View Full Version : Critical parts that are no longer available
Don in VT
11-17-2013, 08:10 PM
Hi All,
Lately there have been a couple of posts that do not leave me with a warm and fuzzy feeling about the future of driving our ZR1's. The posts mention lack of critical components that could make the difference of whether we drive our ZR's or just leave them parked in the garage.
Recent posts mention the Ignition Control Module and the ABS relay. From what I can see these parts are gone and there does not appear to be a suitable replacement for them. I have noticed that when a used ICM has been available, to the Net members, the price has been out of reach for at least some of us.
Has anyone made a list of all the critical NA parts and posted it anywhere ?
Just wondering.
Cheers,
Don in VT
:proud:
Ps: At least for now our ZR is running great and does not need anything but ya never know !!
Z06scentair
11-17-2013, 08:11 PM
Your absolutely correct that dis module is the scary part! I asked for someone to donate a bad DIS for a friend of mine to look at....possibly repair? No one has offered up yet!
tccrab
11-17-2013, 09:14 PM
Can't help with the DIS Module.
As far as I know it's specific to the LT5.
The ABS solenoid I know well.
Here's how to cure it:
http://www.zr1.net/forum/showpost.php?p=98460&postcount=17
http://www.zr1.net/forum/showpost.php?p=98461&postcount=18
'Crabs
Blue Flame Restorations
11-17-2013, 09:20 PM
Member Y-ME (Dan Vlach) is parting out two (2) ZR-1's right now. Having more than one ZR-1 in the stable, I purchase the parts no longer available to put on the shelf. It's a "must".
The list is short. I always make sure I have extra ECM's and DIS modules on the shelf. I even keep ZR-1 specific body panels and AC lines but I'm pretty anal. Nothing else is really a show stopper for me unless I'm missing something?
Most everything else is C4 specific.
Z06scentair
11-17-2013, 09:23 PM
Member Y-ME (Dan Vlach) is parting out two (2) ZR-1's right now. Having more than one ZR-1 in the stable, I purchase the parts no longer available to put on the shelf. It's a "must".
The list is short. I always make sure I have extra ECM's and DIS modules on the shelf. I even keep ZR-1 specific body panels. Nothing else is really a show stopper unless I'm missing something?
Most everything else is C4 specific.
Sale me a dis module?
Blue Flame Restorations
11-17-2013, 09:25 PM
Sale me a dis module?
I would if I could. I have the minimum shelf parts available for each car. Sorry.
I'll start looking for another one and give you the lead.
Kevin
11-17-2013, 09:26 PM
critical parts that are no longer available? pretty much all of them
Z06scentair
11-17-2013, 09:45 PM
I would if I could. I have the minimum shelf parts available for each car. Sorry.
I'll start looking for another one and give you the lead.
Would appreciate that.
Vetman
11-18-2013, 08:57 AM
:cry:This really worries me. My stock z has 64,000 miles and runs and looks great. I don't race it but do drive it a lot. Hope to drive to the gathering in May at NCM. Do these two components fail often, considering I have 64,000 miles? Up to now I thought I could get anything mechanical that wears out fixed!
Blue Flame Restorations
11-18-2013, 08:59 AM
:cry:This really worries me. My stock z has 64,000 miles and runs and looks great. I don't race it but do drive it a lot. Hope to drive to the gathering in May at NCM. Do these two components fail often, considering I have 64,000 miles? Up to now I thought I could get anything mechanical that wears out fixed!
Failures for these compnents are pretty rare but the cars are getting older as well.
XfireZ51
11-18-2013, 09:18 AM
Member Y-ME (Dan Vlach) is parting out two (2) ZR-1's right now. Having more than one ZR-1 in the stable, I purchase the parts no longer available to put on the shelf. It's a "must".
The list is short. I always make sure I have extra ECM's and DIS modules on the shelf. I even keep ZR-1 specific body panels and AC lines but I'm pretty anal. Nothing else is really a show stopper for me unless I'm missing something?
Most everything else is C4 specific.
Brett,
Even the ECMs aren't that critical. For the most part they can still be repaired relatively inexpensively. I would say that the critical path is the DIS module for now.
Blue Flame Restorations
11-18-2013, 10:01 AM
Brett,
Even the ECMs aren't that critical. For the most part they can still be repaired relatively inexpensively. I would say that the critical path is the DIS module for now.
I keep hearing from time to time that people have a hard time finding them or knowing where to get them repaired. Maybe they just don't know where they can get them repaired????
Thanks, Dom.
Bob Eyres
11-18-2013, 10:23 AM
My DIS module went bad very early, about 17 years ago. Replaced under warranty. I try to keep all replaced parts. I'm going to check to see if I still have it.
Anyone ever had one apart?
Don in VT
11-18-2013, 10:55 AM
This is for "crabs",
Thanks for the great solution for the ABS relay. I will save the fix. I actually used a similar solution for a Porsche 928 electrical issue.
Thanks again
Don
For the rest of us:
It seems to me that the DIS module is the electronic equivalent of the 800 lb gorilla sitting in the corner of the garage. We just ignore the potential problem and hope it goes away. I guess it has not been a big issue up till now as that the component has been very reliable. As noted by others the cars are getting older and we will probably see more and more of them fail. As the DIS units fail and if the owners can't find a replacement the ZR becomes useless, period, end of story unless you do an engine swap (back to L98, LT1/4 or LSx.
We use the ZR for lots of long trips and that will come to an end because we can't afford to have a car stuck 1000 miles from home with no way to fix it and drive it back home.
This might be a good time to flip this issue of the DIS over to the Technical Discussion side so folks like Dynomite, Mark H and many others can weigh in if they are so inclined.
I will restart the DIS availability and alternatives (if any) on the Technical side posts.
Thanks all for all the help with trying to understand this issue.
Cheers,
Don in VT
:handshak:
XfireZ51
11-18-2013, 11:58 AM
My DIS module went bad very early, about 17 years ago. Replaced under warranty. I try to keep all replaced parts. I'm going to check to see if I still have it.
Anyone ever had one apart?
Bob,
Because of the environment the DIS lives in, they epoxied the unit. That means it covers all the internal components. Digging all of that out would be a nearly impossible task and even then you probably can't do it without damaging the components. Marc H has an IM unit w/o the epoxy and there's a pic on his website of it. Had the LT-5 been designed w a 24 tooth reluctor, it would have made life much simpler. Maybe Mercury Marine has a solution.
Brett,
Marc H has a stack of ECMs and has a reliable place for hem to be repaired. May want to check w him.
Don in VT
11-18-2013, 12:41 PM
Mark H. has taken a unit apart and actually has a pic of the unit on the inside. It has 2 large IC's and other components. Repairing the unit looks to be difficult.
Thanks
Don
XfireZ51
11-18-2013, 12:58 PM
Mark H. has taken a unit apart and actually has a pic of the unit on the inside. It has 2 large IC's and other components. Repairing the unit looks to be difficult.
Thanks
Don
It was never taken apart. He got it as is. essentially the IM is a co-ECM. Since the basic code for the LT-5 is a derivative of the L98, GM came up with other ways of accommodating the unique aspects of the motor. That's why we have things like secondary injector relays. According to speakers at the Gathering, the need for unique ECM code was a primary consideration in the scuttling the second generation LT-5.
LGAFF
11-18-2013, 01:49 PM
I know Motorola did some of the prototypes, but who ended up making these?
Vetman
11-18-2013, 01:52 PM
I will show my ignorance here. What is a dis an IM and where are they located and what do they do? Is it within the ECM. I do know what and where that is.
GOLDCYLON
11-18-2013, 02:00 PM
I will show my ignorance here. What is a dis an IM and where are they located and what do they do? Is it within the ECM. I do know what and where that is.
The DIS (Distributerless Ignition System) Module resides under the plenum.
They are long NLA in the GM system, They are not being rebuilt at this time. You have to get one at this time from a total car part out.
http://farm8.staticflickr.com/7124/7834731450_02f54041d1.jpg
Paul Workman
11-18-2013, 04:23 PM
Heat is the enemy of electronics of all kinds. The computers and targeting equipment I worked on in the Navy were cooled with chilled water. Failure rate rose exponentially with temperature of the electronics! Never forgot that!
There is some buzz about better air density for HP gains, or easing plenum removal. But, what caught my attention about TB bypassing was significantly reducing the plenum temperature, and thus the DIS module temp failure rate, especially around town driving.
YMMV...
XfireZ51
11-18-2013, 05:24 PM
Heat is the enemy of electronics of all kinds. The computers and targeting equipment I worked on in the Navy were cooled with chilled water. Failure rate rose exponentially with temperature of the electronics! Never forgot that!
There is some buzz about better air density for HP gains, or easing plenum removal. But, what caught my attention about TB bypassing was significantly reducing the plenum temperature, and thus the DIS module temp failure rate, especially around town driving.
YMMV...
Paul,
May want to consider the plenum spacers. They seemed to inhibit heat transfer to the plenum from the IH.
Dynomite
11-18-2013, 07:56 PM
I know you guys are talking about shortage of critical parts.....and failure of some critical parts.
But really....how often does a DIS fail or for that matter an ECM?
I only see one DIS failure in this Poll Classic New Owner LT5 Problems (http://www.zr1.net/forum/showthread.php?t=17014)
XfireZ51
11-18-2013, 08:39 PM
I know you guys are talking about shortage of critical parts.....and failure of some critical parts.
But really....how often does a DIS fail or for that matter an ECM?
I only see one DIS failure in this Poll Classic New Owner LT5 Problems (http://www.zr1.net/forum/showthread.php?t=17014)
Agreed. However, it would be nice to have an alternate for ignition to take advantage of benefits from newer technology.
Dynomite
11-18-2013, 08:57 PM
Agreed. However, it would be nice to have an alternate for ignition to take advantage of benefits from newer technology.
Great point :thumbsup:
Another issue is the interchangeability of parts. 90's for example have Injector Housings and Plenums a bit different than Injector Housings and Plenums on the 91's....The parts can be used with some modifications.
Marc has defined the interchangeability of ECM.......what about the interchangeability of DIS for 90' through 95'?
Marc Haibeck did some testing of the interchangeability of ECM.......ECM Interchangeability TIPS (http://www.zr1.net/forum/showthread.php?p=156570)
LT5 Performance Calibrations (http://www.zr1specialist.com/HAT%20Web/products/LT5%20Performance%20Engine%20Calibrations.htm)
Blue Flame Restorations
11-18-2013, 09:12 PM
Great point :thumbsup:
Another issue is the interchangeability of parts. 90's for example have Injector Housings and Plenums a bit different than Injector Housings and Plenums on the 91's....The parts can be used with some modifications.
Marc has defined the interchangeability of ECM.......what about the interchangeability of DIS for 90' through 95'?
Marc Haibeck did some testing of the interchangeability of ECM.......ECM Interchangeability TIPS (http://www.zr1.net/forum/showthread.php?p=156570)
LT5 Performance Calibrations (http://www.zr1specialist.com/HAT%20Web/products/LT5%20Performance%20Engine%20Calibrations.htm)
I believe that the DIS are interchangable for 90-95. I used one from a 92 on the PhaseII LT5 in EX5023 but had to switch the location of two pins on the harness. Tyler knew to do so. Fired right up.
FAILURES ARE VERY RARE
taximan
11-19-2013, 09:20 AM
Why dont we go to the source and ask Marc how many DIS modules he sees that are bad ?
XfireZ51
11-19-2013, 10:36 AM
Why dont we go to the source and ask Marc how many DIS modules he sees that are bad ?
Marc and I have discussed this a few times. His comment was that MAYBE he has seen 2-3 that were damaged over his 10+ years. It is a very stout piece.
Paul Workman
11-19-2013, 10:39 AM
Man yall skeer me! I went and bought that 1500 dollar part on the big auction site!
Really I scared myself after removing the dang thing a couple weeks back.....remember dynomite?
When I reinstalled it, only put heat sink paste on the intake flat and not the module side. I did coat the entire flat surface but after tightening down I did not pull it back off to make sure it was making contact everywhere.
I contacted Marc and he advised me to remove it and install heat sink paste to both mating surfaces. I haven't done it yet as I don't wanna give Jerry more money for the original gaskets....lol
So I have scared myself, by removing something I knew nothing about. However on a more serious note. I had a conversation with my co-worker and he seems to think I installed the correct amount. His biggest fear was the bolt in connector and bending one of those pins...as he said that would be very easy to do and could be detrimental.
The purpose of the grease is to bridge the gaps between the microscopic peaks and valley on the mating surfaces - with a conductive substance that increases the contact surface area thus promoting heat transfer.
Not going to argue with Marc, but in spite of the heat transfer characteristic imparted by the grease, radiation (of heat) is also an affective part of the heat transfer process; arguably better than the grease itself. My point is some grease is essential, but more isn't necessarily better. Whether you spread peanut butter on both pieces of bread for a peanut butter sandwich or just one, having the right amount can be achieved either way, I suppose.
Now, with regard to NLA parts, i.e. the DIS module, (as I stated on the CF forum): The supply of parted out LT5s has pretty much kept up with the demand - over all. This is in part because the dang things rarely fail. So, in the rare case one does fail, there has (according to Marc I've spoken to and others) always been one or two around. There aren't (up to now) been any ZR-1 parked indefinitely for lack of a DIS module. All it would take to upset the balance and change that is to create an unfounded panic resulting in hoarding of those truly limited parts to take place. I won't fault you or anyone for picking up a spare part here and there. But, as pointed out, $1500 paid for a non-emergency (running LT5) is the type of thing that often does promote panic hoarding; a "run on the bank" if you will.
However, and that said, etc, etc, whenever there is a demand, a supply usually comes along; we've seen many a cottage industry pop up. Jerry's Gaskets, is but one example where parts NLA from GM have been replaced: & often times are improved on in the bargain (thank you Jerry!)!
And so... Soon it may be too for the DIS as well. In the mean time, the LSx motors too have the equiv of distributorless ignition, and the key to adapting the LT5 to (some versions of) the LS electronics (among other things) is the 24 "tooth" reluctor the LS (ECM) requires. Posted within the last week(?) on this web site (someone help me please) I read where one of the many talented people here has built an external reluctor that will allow the LS hardware and software to drive the LT5 ignition - potentially ending the OEM DIS issue.
Rustling up parts for the LT5 can be annoying, compared to visiting any GM parts counter with cash in hand. But, because these motors are so bullet proof, breaking one - even in extreme demand (racing) situations - is rare enough that adequate parts can be had, if not just immediately.
I don't loose any sleep over it.
Paul Workman
11-19-2013, 10:42 AM
Agreed. However, it would be nice to have an alternate for ignition to take advantage of benefits from newer technology.
:thumbsup:
taximan
11-19-2013, 11:45 AM
The purpose of the grease is to bridge the gaps between the microscopic peaks and valley on the mating surfaces - with a conductive substance that increases the contact surface area thus promoting heat transfer.
Not going to argue with Marc, but in spite of the heat transfer characteristic imparted by the grease, radiation (of heat) is also an affective part of the heat transfer process; arguably better than the grease itself. My point is some grease is essential, but more isn't necessarily better. Whether you spread peanut butter on both pieces of bread for a peanut butter sandwich or just one, having the right amount can be achieved either way, I suppose.
Now, with regard to NLA parts, i.e. the DIS module, (as I stated on the CF forum): The supply of parted out LT5s has pretty much kept up with the demand - over all. This is in part because the dang things rarely fail. So, in the rare case one does fail, there has (according to Marc I've spoken to and others) always been one or two around. There aren't (up to now) been any ZR-1 parked indefinitely for lack of a DIS module. All it would take to upset the balance and change that is to create an unfounded panic resulting in hoarding of those truly limited parts to take place. I won't fault you or anyone for picking up a spare part here and there. But, as pointed out, $1500 paid for a non-emergency (running LT5) is the type of thing that often does promote panic hoarding; a "run on the bank" if you will.
However, and that said, etc, etc, whenever there is a demand, a supply usually comes along; we've seen many a cottage industry pop up. Jerry's Gaskets, is but one example where parts NLA from GM have been replaced: & often times are improved on in the bargain (thank you Jerry!)!
And so... Soon it may be too for the DIS as well. In the mean time, the LSx motors too have the equiv of distributorless ignition, and the key to adapting the LT5 to (some versions of) the LS electronics (among other things) is the 24 "tooth" reluctor the LS (ECM) requires. Posted within the last week(?) on this web site (someone help me please) I read where one of the many talented people here has built an external reluctor that will allow the LS hardware and software to drive the LT5 ignition - potentially ending the OEM DIS issue.
Rustling up parts for the LT5 can be annoying, compared to visiting any GM parts counter with cash in hand. But, because these motors are so bullet proof, breaking one - even in extreme demand (racing) situations - is rare enough that adequate parts can be had, if not just immediately.
I don't loose any sleep over it.
Great assessment Paul. I think you are right on !!
BigJohn
11-19-2013, 01:48 PM
The purpose of the grease is to bridge the gaps between the microscopic peaks and valley on the mating surfaces - with a conductive substance that increases the contact surface area thus promoting heat transfer.
Not going to argue with Marc, but in spite of the heat transfer characteristic imparted by the grease, radiation (of heat) is also an affective part of the heat transfer process; arguably better than the grease itself. My point is some grease is essential, but more isn't necessarily better. Whether you spread peanut butter on both pieces of bread for a peanut butter sandwich or just one, having the right amount can be achieved either way, I suppose.
Now, with regard to NLA parts, i.e. the DIS module, (as I stated on the CF forum): The supply of parted out LT5s has pretty much kept up with the demand - over all. This is in part because the dang things rarely fail. So, in the rare case one does fail, there has (according to Marc I've spoken to and others) always been one or two around. There aren't (up to now) been any ZR-1 parked indefinitely for lack of a DIS module. All it would take to upset the balance and change that is to create an unfounded panic resulting in hoarding of those truly limited parts to take place. I won't fault you or anyone for picking up a spare part here and there. But, as pointed out, $1500 paid for a non-emergency (running LT5) is the type of thing that often does promote panic hoarding; a "run on the bank" if you will.
However, and that said, etc, etc, whenever there is a demand, a supply usually comes along; we've seen many a cottage industry pop up. Jerry's Gaskets, is but one example where parts NLA from GM have been replaced: & often times are improved on in the bargain (thank you Jerry!)!
And so... Soon it may be too for the DIS as well. In the mean time, the LSx motors too have the equiv of distributorless ignition, and the key to adapting the LT5 to (some versions of) the LS electronics (among other things) is the 24 "tooth" reluctor the LS (ECM) requires. Posted within the last week(?) on this web site (someone help me please) I read where one of the many talented people here has built an external reluctor that will allow the LS hardware and software to drive the LT5 ignition - potentially ending the OEM DIS issue.
Rustling up parts for the LT5 can be annoying, compared to visiting any GM parts counter with cash in hand. But, because these motors are so bullet proof, breaking one - even in extreme demand (racing) situations - is rare enough that adequate parts can be had, if not just immediately.
I don't loose any sleep over it.
Did you really typ all this??
I can see why you would need sleep!
:cheers:
Z06scentair
11-19-2013, 07:51 PM
The purpose of the grease is to bridge the gaps between the microscopic peaks and valley on the mating surfaces - with a conductive substance that increases the contact surface area thus promoting heat transfer.
Not going to argue with Marc, but in spite of the heat transfer characteristic imparted by the grease, radiation (of heat) is also an affective part of the heat transfer process; arguably better than the grease itself. My point is some grease is essential, but more isn't necessarily better. Whether you spread peanut butter on both pieces of bread for a peanut butter sandwich or just one, having the right amount can be achieved either way, I suppose.
Now, with regard to NLA parts, i.e. the DIS module, (as I stated on the CF forum): The supply of parted out LT5s has pretty much kept up with the demand - over all. This is in part because the dang things rarely fail. So, in the rare case one does fail, there has (according to Marc I've spoken to and others) always been one or two around. There aren't (up to now) been any ZR-1 parked indefinitely for lack of a DIS module. All it would take to upset the balance and change that is to create an unfounded panic resulting in hoarding of those truly limited parts to take place. I won't fault you or anyone for picking up a spare part here and there. But, as pointed out, $1500 paid for a non-emergency (running LT5) is the type of thing that often does promote panic hoarding; a "run on the bank" if you will.
However, and that said, etc, etc, whenever there is a demand, a supply usually comes along; we've seen many a cottage industry pop up. Jerry's Gaskets, is but one example where parts NLA from GM have been replaced: & often times are improved on in the bargain (thank you Jerry!)!
And so... Soon it may be too for the DIS as well. In the mean time, the LSx motors too have the equiv of distributorless ignition, and the key to adapting the LT5 to (some versions of) the LS electronics (among other things) is the 24 "tooth" reluctor the LS (ECM) requires. Posted within the last week(?) on this web site (someone help me please) I read where one of the many talented people here has built an external reluctor that will allow the LS hardware and software to drive the LT5 ignition - potentially ending the OEM DIS issue.
Rustling up parts for the LT5 can be annoying, compared to visiting any GM parts counter with cash in hand. But, because these motors are so bullet proof, breaking one - even in extreme demand (racing) situations - is rare enough that adequate parts can be had, if not just immediately.
I don't loose any sleep over it.
Paul,
Im with you and everything you said. Im not the type who buys up parts and stores them.....thats my old man. Need a part for a 20's,30's,40's,50's,60's car or truck? He has got it.
My reason was just to have a backup in case the original didn't make it.
You guys are a wealth of knowledge and I look forward to contributing my expertise to many discussions!
Franke
11-19-2013, 08:44 PM
I really don't believe the LT5 will become a 600 pound paper weight. There is always an alternative solution. Just look at what these guys on here are already doing to improve the ignition system and other stuff with parts from the newer design engines etc. Z owners take heart - we'll be ok.
Vetman
11-19-2013, 10:37 PM
Thanks, does this mean I can use my AC next summer and not worry about cooking my DIS.....:-D
lisounds
11-20-2013, 12:17 PM
I have been reading this thead. very interesting
does anyone have a picture of this part
both in and out of the car
what is the gm part number ?
THE SKY IS FALLING !!
NO it's not.
This part very rarely fails on these engines. There are spares floating around. Don't be foolish and buy something and pay a premium for a part you will never need.
I have been reading this thead. very interesting
does anyone have a picture of this part
both in and out of the car
what is the gm part number ?
Pictures of virtually every part in the LT5 engine
do a search for ignition module.
www.jerrysgaskets.com (http://www.jerrysgaskets.com)
BigJohn
11-20-2013, 06:01 PM
I see no problem!
Look at Paul's car; it is making a comeback.
In the early 80's we could no longer get a water pump for the 426 Hemi from Mopar parts.
So we had an adapter made so we could use a 454 water pump.
:cheers:
efnfast
11-20-2013, 06:15 PM
Somehow I'm not worried about a lack of parts. With the talent I've seen in this group, someone, somehow will come up with what is needed by adapting, or manufacturing.
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