Ignition module ground

[8upZR1]

I was looking at the schematic for the LT5 ignition module and saw that it has external and internal grounds. I realized then that the internal ground on my module has not been connected as I have removed the module from under the manifold for troubleshooting and now lay it on the windshield. I have since added an extra ground wire to the heat sink plate to simulate the internal ground, but it has had no positive effect. I was wondering if it is possible to fry the ignition module by cranking the motor without this ground attached. Anybody have a clue?

[Tyler Townsley]

Shipped the dis checker and scope today. Should help answer that question.

Tyler

[8upZR1]

Thankyou Tyler, I will forever be indebted to you. If you are ever in the Thunderbolt/Savannah area and in need of food/shelter/clothing please do not hesitate to ask.

[Tyler Townsley]

There is a pigtail so you can check the module without removing the it. In your case you probably need to pull the module and look at the signal as it comes out of the module before going to the coil. On one of my dis modules the signal looked good until it got to 400 rpm then it became obvious it was bad as the signal lost its uniformity. I just hope it helps.

Tyler

[8upZR1]

I hope so too. At this point I am totally stumped. Ever since this problem started I have removed the module from under the plenum and now I just lay it on the windshield so that I can switch between modules and troubleshoot without hassle. Once the car runs I will find a suitable location and lengthen the harness so that I do not have to mess with the plenum to access the DIS. I cant imagine that both of my modules are broken but if they are I will actually be pleased to know what is causing my problem. At this point I am worried that the modules will check out OK. What then will I do? I have learned from the previous owner that the car has gone through four ECM's. In addition I used to have a problem where the car seemed to run extremely rough and lacked power, but this situation only occured when the motor was cold. Once the engine got to the upper range of the temp gauge it would run great. After I installed a chip the motor never got hot enough that the problem went away so I had to ditch the chip. Nobody I have asked has ever heard of such a problem. Most of the time things get worse as the car heats up, not the other way around. I am thinking maybe this vette is cursed and I will never get everything sorted out properly.

[Tyler Townsley]

4 ECMs? There is wireing problem between the ecm and the dis module. I think you will find the DIS module is bad. You need to use the schematics here and chase out every wire to the end. IE pull the connectors at the ecm and dis and run a continuity test end to end. It almost sound like your ecm in and tach out lines are switched on the dis. This is the major difference between the 88/89 cars and the 90+ cars is that wireing difference. If someone was using a 89 refrence for the wiring or replaced the engine compartment harness with a 89 that would be the problem. After chasing the wireing use the other refrences to make sure you have the right info on the line.

http://www.sirgalahad.org/tyler/misc/90ecm1.jpg
http://www.sirgalahad.org/tyler/misc/90ecm2.jpg
http://www.sirgalahad.org/tyler/misc/90ecm157.jpg
http://www.sirgalahad.org/tyler/misc/90ecm158.jpg
http://www.sirgalahad.org/tyler/misc/90ecm159.jpg
http://www.sirgalahad.org/tyler/misc/90ecm160.jpg
http://www.sirgalahad.org/tyler/misc/90ecm161.jpg

Guess I should have included the ecm breakout box too.

Tyler

[8upZR1]

Continuity between the ECU and DIS wires was one of the first things that I checked, and everything checked out OK. I dont have an oscilloscope but I did hook up a volt meter to the DIS ref out high, ref low, est signal input, tach output, and bypass circuit, at the diagnostoc connector and they all looked good, at least as much as I could tell. The voltmeter averages the high and low and what I got was 2.5V ref high, 0v ref low, .3V est, 3.6v tach, and 0v bypass. This is exactly what the manual says I should get. Obviously the osciloscope is the only way to know exactly if the square wave is being produced but this seems bad to me. My only concern was that maybe the est signal was a bit high, but I guess it is close. The timing should be non existant if some critical wire is unplugged, but I am still getting combustion from all intake ports. I hope to die having solved this issue......

[Tyler Townsley]

4 ECMs is not a good thing. You will be able to look at the waveforms with the scope I sent. Bad gas will sometimes cause symtoms you describe.

Tyler

[8upZR1]

Tyler, I have done checked everything I can and it all looks great. One thing I was wondering is what about the ISS is what RPM is it simulating when it is turned all the way down on the crank setting. I am getting that it is making 1800 RPM. At least that is what my MSD says and it is usually very accurate. Could this be my problem? I can't imagine that the cranking setting would be outputting 1800 rpm. When I turn the knob to the cruise setting it is making a signal equivalent to 6500 rpm. Kinda high for cruising but if this is normall then cool. I guess I will empty the gas tank and refill with new gas, but I doubt that it would make a difference. I was wondering how you have an 88 ZR1. Isn't 90 the first year? Is your 88 a transplant or an engineering mule or something like that?

[tccrab]

I was wondering how you have an 88 ZR1. Isn't 90 the first year? Is your 88 a transplant or an engineering mule or something like that?


Tyler's '88 ZR1 (Queenie) is the only surviving '88 prototype, and one of a handfull of prototype/test cars/mules that somehow survived even though GM had (and still has) a strict policy of destroying any and all development cars.
Here's a link to some nice pics of Queenie, and I've seen a nice writeup on her somehwere, ahha yes, here it is:
www.sirgalahad.org/tyler/prototype/APrototypesStory.doc
http://forums.corvetteforum.com/showthread.php?t=1172641

The earliest prototype I've heard about/seen is a 1986 ZR1, one of the 4 found in a Lotus boneyard in the UK. Here's a nice web site detailing the discovery and rebuilding of one of the cars found there:
http://www.eurovettes.com/zr1_story.htm
And a picture of the aforementioned Lotus boneyard:
http://corvetteactioncenter.com/gallery/showphoto.php/photo/775/sort/1

There's a 1987 prototype car in the NCM, here's a pic:
http://www.corvetteactioncenter.com/gallery/showphoto.php/photo/772/password/0/sort/1/cat/all

There were a total of 84 1989 ZR1 evaluation cars that were built to promote the 1990 ZR1. Members of the press and special guests were invited to drive them and review them for their publications. Many of these cars most likely still survive, and show up at a few car shows every year. These cars are readily identified by their "salad shooter" wheels with the solid center caps:
http://temp.corvetteforum.net/c4/scoob/stealth02.jpg
'90 with exposed lug nuts:
http://www.96lt4.com/ZR1/myll90.jpg

TomC
'90ZR1 #792

[Tyler Townsley]

Tyler, I have done checked everything I can and it all looks great. One thing I was wondering is what about the ISS is what RPM is it simulating when it is turned all the way down on the crank setting. I am getting that it is making 1800 RPM. At least that is what my MSD says and it is usually very accurate. Could this be my problem? I can't imagine that the cranking setting would be outputting 1800 rpm. When I turn the knob to the cruise setting it is making a signal equivalent to 6500 rpm. Kinda high for cruising but if this is normall then cool. I guess I will empty the gas tank and refill with new gas, but I doubt that it would make a difference. I was wondering how you have an 88 ZR1. Isn't 90 the first year? Is your 88 a transplant or an engineering mule or something like that?

The ISS crank setting is 400 rpm. I am unfamiliar with the MSD setup you are talking about. If the the spark event is reported as 1800 rpm at start then that is what the ecm and dis thinks the engine speed is. I would think would lead to a spark event in the cyl too far in advance of valve closing and cause backfire and an inability to start. If the gas is bad it will smell different. Using the scope compare the crank sensor and cam sensor signals to that created by the simulater, they should be the same.
Where is the rpm signal taken from with the MSD? On the zr1 the dis has a pin out that goes directly to the dash tach which is why the tach reports the rpm correctly and the aldl software does not read correctly over 6350.

The story of the 88:

http://www.sirgalahad.org/tyler/prototype/APrototypesStory.doc

Tyler

[8upZR1]

The MSD calculates RPM from the coil signal then outputs it in standard squarewave to drive a tach or shift light, or in my case a digital window switch for my NOS, it displays RPM. I will compare the two signals tomorrow. When a spark plug is laid against the intake manifold and the engine is cranked it is obviously a much slower spark sequence than when the ISS is used. I could tell immediately even without a scope. The sparks come much more rapidly from the ISS. Ifthis is in fact my problem then what do you think the cause is? Do you think it is the sensors failing to read properly or the DIS failing to read the signal?

[Tyler Townsley]

Tyler's '88 ZR1 (Queenie) is the only surviving '88 prototype, and one of a handfull of prototype/test cars/mules that somehow survived even though GM had (and still has) a strict policy of destroying any and all development cars.
Here's a link to some nice pics of Queenie, and I've seen a nice writeup on her somehwere, ahha yes, here it is:
http://forums.corvetteforum.com/showthread.php?t=1172641

There's a 1987 prototype car in the NCM, here's a pic:
http://www.corvetteactioncenter.com/gallery/showphoto.php/photo/772/password/0/sort/1/cat/all

TomC
'90ZR1 #792

Same car. It was produced on the 87 assembly line in June of 87 with an 88 vin on the frame as a 88 production prototype.

Tyler

[8upZR1]

You are lucky to have come across such an amazing piece. Has the motor and tranny been put in? I would love to know how the car compares to the production ZR1.

[8upZR1]

The manual for the ISS says that U2 is the proper setting, do you by any chance remember if this is correct?

[Tyler Townsley]

The manual for the ISS says that U2 is the proper setting, do you by any chance remember if this is correct?

According to this:
http://www.sirgalahad.org/tyler/misc/dis_1.jpg
U2 is the correct setting.

It almost sounds like you have reversed the cam and crank sensor input on the ISS, ie 1800/4= 450 rpm the dis is seeing a cam signal and using that to calculate spark. The thing to remember is under 400 rpm the dis controls the spark based on the rpm input from the crank sensor.

Couple of questions, the dash rpm does not work? Is it bad or is the dis not showing a rpm signal on DIS pin E?

You said the car ran ok before the blown gasket yet you then qualify that by saying it ran ok once it got warm. Something to check is the wireing to the fuel pumps, in the zr1 on key on you get a 2 sec pulse in primary pump and when it is cranked bot pumps come on until ~180 degress when the secondary pump shuts off. If you have a way of checking the fuel pressure at the rail it should go to ~45 psi and hold there.

It is very difficult to diagnose from long distance and equally hard to diagnose alone using tips from online. Been there twice, once it ws a broken exhaust valve spring that took me 2 1/2 months to diagnose. Then it was the prototype which took 2 years to figure out.

The ptype is running but it took so much to get running that I may hae damaged the bearing as it has very low oil pressure, something I will fix in the future.

Tyler

[8upZR1]

OK I will clarfiy. The car ran 100% when the power key was out, absolutely not a single problem. With the key turned to full engine power and at full throttle the car would run like sh*t, unless it was hot. I know this car since it was new, it was purchased by a doctor in 1990 and sat in a garage untouched till about 96 (factory plastic on seats, 0 miles). One day the good docs mercedes had a flat so he tried to drive the vette. Obviously it didn't work, no battery, etc. I was banging his daughter at the time and he asked me to get it runnng cause he wanted to start driving it. I put new battery in and it ran great, awsome power, ZR1 power. He drove and abused the car like no other and things started to break, like the ECU's. The car sat outside for long periods of time and the paint went south. This guy drove the car 10 miles a day and literally never once put the valet key into the slot. Last year he tried to trade the car in for a Toyota and the dealership would not even give him 4K for the trade in value, so that is how I got it. It was totally screwed up when I took over and ever since then I have been fixing stuff. The full throttle/hot condition is only when the full engine power is on. I thought it was from the actuators so I pinned them open to see if that helped, it did a little but the car still did not perform like it used to. The doctor is super cheap and around here there is a gas station that gives 7 cents off premium on Tuesdays so that is what he filled it with, but the place puts something like 10% ethanol in the gas. This messed up the secondary injectors and I replaced those and it helped a little. All this time the car was running great except for the full throtttle/full power, low temp situations. When I pulled the heads I found that the secondary ports were comletely clogged with carbon and there was all sorts of large chunky carbon deposits in the breather areas of the valve covers. So now I am thinking that this previous issue was due to diminished cross sectional area of the secondary ports and hopefully it will be gone when I finally get it running.

This is all probably confusing, and I know that online is probably the worst way to diagnose an egine problem but I have never really worked on a ZR1 or any vete for that matter. Most of my experience is in turbo 4's, Porsche, and Modular Mustangs. I have learned a great deal from the ZR1 forum and net registry sites. Without you and these pages I would be completely lost.

The tach signal at the DIS diagnostic connector is great, the tach is broken at the cluster. It shows something like 4 to 10 times the actual RPM. Idle is 4000, when you blip the throttle a little is shoots past the gauge markings. This problem started before I took over ownership of the car.

The fuel pumps are working great. I run two 255 LPH walbro pumps. Why so much? To feed the wet kit of course. I have fuel pressure gauges that monitor pressure in the rail. It is ussually around 55 psi and it holds it for at least 15 minutes. I have removed the fuses for each pump and checked the fuel pressure for the individual pumps and they check out, about 52 psi each. I have also noid lit all of the primary injectors, they get signal. When I remove the plenum I get nice combustion out of all the intake ports, in sequence of course. I am stumped.

I am sorry to hear about the possible bad bearing. It seems that there is always something to fix. At least you will not suffer from having to much free time.

[Tyler Townsley]

OK, you have done more checking than I thought. Back to the MSD and the dis.

Put the scope on the dis output to the coils one at a time and see what the difference looks like with the ISS and the crank sensor. This signal should be the same in amplitude as you turn the knob with the ISS in the ckt. as you increase rpm the spikes get closer togeather but should remain the same. On the one dis I had when you got over 400 rpm the spikes became random in amplitude and regularity.

Can you look at the signal in pin E on the dis or pin F on the diag connector. This is the tach line and it should match your MSD, where do you tap in the msd and how does it account for waste spark? Could it have loaded the dis ckts taking out something internal in the dis? NOS huh, you and some guy I know in Denver would get along real well. LOL


Tyler

[8upZR1]

I will check the output to the coils today. The MSD is spliced in between the coils and the DIS. MSD has adapters where you remove the coils and place the adapter in between the coils and the base, with the adapter basically sandwitched between them. Each adapter has four wires running from it where you make connections with the MSD. Each coil has two wires and the adapter cuts these into four. The four wires are two that come from the DIS, and two that go to the coils. The MSD takes the signal that would normally come into the coils and changes it accordingly, more energy, retard, two step, multiple spark output, etc. Then it outputs the signal to the coils and controls them. There is a harness that attaches the box to these wires, and it also comes with a plug that can be inserted into the harness instead of the box. The plug just connects the cut wires again so that the ignition is back to stock. Swapping between the MSD and the plug makes no difference. The MSD figures the RPM from the coil input, the coil positive wire I think. Then it converts it into a standard square wave to drive a tach or what not. If the signal out from the MSD is 1800 rpm then the input is 1800 RPM. I have called MSD tech and they claim that it is impossible for the box to alter the signal. Input to output is 1 for 1. The box has settings for waste spark or coil on plug style systems. I have been running this box on my mustang for years and the vette for a few months before the head gasket failure and I think it is a great ignition. The only thing that compares is a boost-a-spark from Kenne Bell and it doesn't have any adjustability, it only increases spark energy, but the tradeoff is installation ease.

[8upZR1]

I have just compared the coils input signals from the DIS using the ISS and then the crank sensor. On all channels the signals are the same except for the frequency of the waves. The crank sensor, which is a lower RPM signal, has the same magnitude of wave as the ISS. The peaks are closer when I run the ISS. As I turn the ISS knob from crank to idle to cruise the peak to peak spacing decreases but the magnitude of the waves and their form stay the same as with the crank sensor. I checked again to see if everything was hooked up correctly and sure enough the crank end of the ISS was used with the creank sensor input of the DIS. It still gives me 1800 RPM in the Crank position. I think that maybe this is the problem. The DIS is not interpretting the crank input signal correctly. I have no way of measuring the rpm corresponding to the signal from the crank sensor, but it is definetely on the low side. I would say a maximum of 150 RPM. I dont know what the starter should be spinning the motor to but this seems low to me.

[8upZR1]

I have had no success but I did notice that wheneve I try to start the motor the A/F gauge reads between lean and stoich. My mustang will only start when the mixture is rich. Has anybody taken a look at the A/F ratio on their ZR1 when the motor is cranking? A few months ago I asked all the various people who burn chips for the ZR1 if they could burn me a chip or two with different fuel settings for cranking and I was told by everyone that it was impossible, or that it would be easier and more cost effective to wire up a stand alone injection system. Does anybody know of a method to adjust fuel mixture on these cars without resorting to one of those Jap piggyback boxes?

[Tyler Townsley]

I have had no success but I did notice that wheneve I try to start the motor the A/F gauge reads between lean and stoich. My mustang will only start when the mixture is rich. Has anybody taken a look at the A/F ratio on their ZR1 when the motor is cranking? A few months ago I asked all the various people who burn chips for the ZR1 if they could burn me a chip or two with different fuel settings for cranking and I was told by everyone that it was impossible, or that it would be easier and more cost effective to wire up a stand alone injection system. Does anybody know of a method to adjust fuel mixture on these cars without resorting to one of those Jap piggyback
boxes?

The start enrichment calibration can be changed. No one has found a need to do it so they are not sure what to change and by how much without the car right there to see the result of thier efforts. If you have a lean start condition I would look at the primary injector function first.

The motor mounting in the zr1 is different than a normal 350 which is why they have a different cradle, that may be changable but it could not be used for the lt5.

If you review the testing procedures for the dis you will note the wornings about using a vtvm to check outputs. I assume this is because the additional loading will damage the internal cktry. Based of your results with the ISS I think the dis module or the crank sensor is bad, I think the MSD may have cause the dis to overheat and fail. On way would be to install your dis in another running car to see if it exhibts the same problems.

Tyler

[8upZR1]

I agree. I believe the crank and cam sensors are good. I used the ISS in check mode and the green lights flashed indicating that the sensor output was good. The lights only flashed faintly, but they did flash, so I assume that they passed whatever testing the ISS machine performs. Tyler please PM me with your address so that I can return the ISS and scope. Thankyou again for letting me borrow them.

ZR1 MK are you still willing to instal my DIS in your car to see if it is good?

As for the lean starting condition, I don't believe it has anything to do with the problem. The injector spray pattern looks good, noid lights check out good, fuel pressure is good. Earlier today I sprayed extra fuel into the manifold from my NOS system, two 0.018 jets, and it did nothing, not even a change in A/F ratio. I guess that means that the fuel is burning up in the manifold. So I am back to thinking that the timing is totally F'd. Somehow the spark is coming as the intake valves are open. Perhaps I will try swapping plugs. Swapping CYl #1 @ 6 deg BTDC with cylinder that has intake valve open. Dunno if it is worth the effort but at this stage I am trying anything that could remotely be possible, no matter how unlikely.

[ZR1 MK]

ZR1 MK are you still willing to instal my DIS in your car to see if it is good?
Yes. I remember the DIS located under the plenum and being able to unplug from the wiring harness. Also, will your 1991 DIS (if I remember correctly) work on my 1990 engine? Some say the part number for 1990-95 is the same, while others say they are different. We need to confirm this. Keep in mind, for shipping cost and time frame, Im located in NY. I will be available after Im back from my next track event that puts me home on July 18.

[8upZR1]

ZR1 MK my car is a 90, so no problem there. I will PM you tomorrow about specifics. I have since ordered a new DIS with many prayers that it is in fact the root of all evil concerning my problem. I am at this point doubtful that the DIS is bad though. I am thinking more and more that I have some other issue.

I was wondering if it would be possible to start the LT5 by unplugging the ECU all together and leaving the DIS plugged in. For fuel I will spray the wet side of my NOS system. All I am really hoping to accomplish is to cut off the fuel injectors without removing the plenum and actually unplugging them from the harness. Will the DIS produce a spark without the ECU? I am thinking that maybe the mixture is way off and if I could adjust it with pills to get it in the ballpark I could go from there and find somebody who would be willing to burn a chip with less fuel without actually having to have the car in front of them. I am not looking for the car to run on the nozzles, just sputter a little to let me know that it is in fact the A/F ratio that is holding me back.

Another thought of mine concerned the hydraulic cam followers. Can they pump up? If so can they pump up to the point that the intake valve does not close? I was thinking maybe the intake valves are staying open and that is why I am getting combustion in the ports. Silly thought, but I have not much else to think about these days.

[ZR1 MK]

I wounldnt run the car by disconecting items you mention. Also, if the lifters operated fine before, they will be fine now.
If you want, give me your phone number, or you can call me.

[8upZR1]

No need. I think it is F'd, totally F'd. I cranked it over today and it sounded kinda funny, like something was missing. It almost sounded as if the motor was spinning freely. It was distinctly different than ever before. I checked all the usual stuff and everything looked OK. Then I ran a compression test and behold, one cylinder gave 30 psi, the others only about 5. About 2 weeks ago I checked the compression and it was in the high 180, low 190 range. I did not hear anything bang or clunk, the starter did not even seem to strain. I am guessing that the whole thing is trashed. OH well. I would like to thank everyone who gave their input on my previous dilema. Earlier in the week I was thinking about how difficult it would be to swap out the LT5 for an LS series engine. I have come to the conclusion that it would not be worth the trouble. However, I have located a suitable SB2.2. Its 355 CID, 820HP, carb, distributor. A nice piece. I am thinking that maybe the trouble will be worth the final result. At least I wouldn't be thinking about ignition modules, and computer jive. I have researched this today and it seems that the parts that are incompattible can be swapped with those from an LT1 car without hassle. I hate this LT5.

[tccrab]

This is sad news indeed.
Are you SURE that the compression is lost, and you don't just have leak in your compression tester?

I'd *really_really_really* hate to see you give up after so much time and effort that you've spent, and no doubt a small fortune that you've had to dish out.

Get a second opinion before you give up the ghost.

Surely there's fellow ZR1'er somewhere reasonably close by you that can lean on for support.

Guys?
Are you listening?
Time to step up to the plate!!!
One of our own is ready to lay down his arms in defeat.

Tyler has already stepped up and sent some test equipment, is there anyone within reasonable driving distance who has the experience to help this guy diagnose/repair his baby?

It'd almost be a sin to drop in one of those ugly new generation small blocks, although a new LS7 at 550hp would almost make the ugly bearable....

I'd offer to drop on by, but California is a long_long way from Georgia.

'Get 'er Dunn!

TomC
'90ZR1 #792

[8upZR1]

Its OK. I still have a Mustang that is plenty fast. Maybe some day I will find the motivation to tear the motor apart again. Its definetely toast. I checked the Mustang with the same gauge and its working fine. I guess I just tried cranking it over one too many times. Sounds kinda like a 928 with a snapped timing belt, although I doubt the chain broke, but with my luck anything is possible. Where I live I am the only person with a ZR1 for at least 100 miles. Even the Chevy dealership here thinks ZR1 means 16 valve pushrod motor. To say its kinda backwards, backwoods, backside is a total understatement. Again I thank everyone who tried helping me out. Special thanks to Tyler for sending the ISS, he doesn't even know me and sent out a package, total class act. Tyler for president. If I ever get the ZR1 running I will post.

[tomtom72]

I would just like to say how badly I feel for what has happened to your Z.:cry:

Good luck in your future plans!:thumbsup:

Tom

[8upZR1]

This probably does not belong in this post, but I was looking on Ebay for ZR1 engines and found an 89 MY engine with drivetrain and front clip. The date stamp is 88. I noticed the PCV system is different than on my car. I was wondering how similar this motor is compared to my motor and if the rated power output was different. The starting bid is 11K, a bit high IMO but if this motor has some sort of additional collector value since it is an 88 then maybe the price is right.

[ShawnZR-1]

I have read through this thread with a bit of dispair since I'm currently rebuilding my top end. I pray that I don't run into the problems you have but I have been guided by Mike at EES so I feel quite confident.

In any case, I would be very willing to spend some time with you (ROAD TRIP!) troubleshooting your beast once mine is back on the road. Don't give up on it, but certainly take a break from it. Only bad things come from frustration.

Just know we're out here to back you up. I'm not an expert by any means, but I have a decent troubleshooting mind and have a knack for looking at things from different perspectives. We can and will get your Z back in tip top shape!!!!

[Tilbac]

Good news

[8upZR1]

I have finally had a day of free time and have disassembled the LT5 once again. It gets remarkably easier every time. Anyway I have found the culprit. A true mystery, now solved. I dunno how or when it happened. I cant imagine that I did not notice this the last time I assembled the motor. But here it is.....the F F F F'ing hydraulic followers. 17 of the 32 are locked in a fully extended position. I have put a few in a vice and tried to collapse them, but no luck. They will not budge, not even for a hammer. They are somehow solid, and fully extended. I imagin that most or all of them were on the intake side. I did not pay attention due to some extraordinary circumstances. Normally I would label where they come from but I was interrupted, I then turned the head on its back and they all fell out before my brain could think about it. Oh well, but since I had combustion in the intake manifold I assume that most are from the intake and they held the valves open even when riding on the base circle of the cam. How this happened, I do not know. If a piston hit them I would think that they would be stuck in the retracted position. I remember checking them before I put the motor back the first time and they were fine. I always kept them in a zip lock bag with oil.

So, my question to everyone is this: Does anyone have a set of lifters for sale? Does anyone know specifics about what type of audi lifter will work? I have heard A8 but what year? Intake or Exhaust? Does anyone know what has gone wrong with my set?

[8upZR1]

After consulting with a santeria priestess named Pearla, I have found a solution to my broken lifters. I soaked them in the urine of a virgin overnight and left them in a room full of pennies with silver pieces at the corners.....and what do ya know, they actually do move now. And to think that women dont have a clue. Anyway, the heads are back on and hopefully today will be the last time I need to work on this thing. I will post results.

[tomtom72]

I remember a thread somewhere, here or at CF or CAC, about lifters. Someone determined that the lifters from the Aurora motor were the same size lifter bore. I don't know if this is of any use to your situation.:o

Good luck with the motor!:thumbsup:

:cheers:
Tom