Drivabilty issue.

[BBBAD94ZR1]

I hope you guys can help me out. I got my Z home today a 94 zr1 10k miles. The owner washed off the engine with a hose a big no[-X .
I blew it off and the air cleaner had some water in it. No much. Here is the issue. I drove car for around a half hour mellow, I got on it a few times not going past 4500 rpm and I noticed a stumble. Drove it a bit more and I noticed if I shifted form 3rd to 4th at low rpms the car hesitated kind of like it was missing or starving for fuel got on it and it did not happen for a while. I let the car sit for a few hours took it back out and it ran better however when driving in 5th around 50 to sixty under accel the car stumbled. Go to 6th and it really ran bad drive it hard and its ok when in to high gears under light accel it stumbles sometimes?:icon_scra :icon_scra .
The car also had the chip changed here is the number of the one not in the car GM#16209008, the one in the car is 12528772 gr.3.670. Anyone know what the difference is between these two?
Please give me your input. Anyone know of a gm dealer in Nj who has a Zr1 tech? I hope its something easy to remedy.

Thank you
Ray

[black92]

sounds like an o2sensor. my 92 done the same thing. you might put it on a computer to check. hope that helps

[WB9MCW]

i would say first thing to do is to figure if it is electrical (spark/ignition...which might be from the hose job) or mechanical ( suspect would be bad fuel pump psi or injectors...low miles can hurt both by sitting around too much!!!) funny no dic light to help with trouble codes clues...sorry to see prob's right off the bat with ur new baby but not to worry ull get her up to snuff!!! u need to get tight with tomtom he just went through the new to u low miles zr-1 blues...TT will be a great asset to u for ideas because he has just been there!!! I sent him a pm so he will p/u on the post!!! Plus TT lives in NY!!!

[tomtom72]

Hi Ray,

Listen, does she give any "SES" light? Did you check for codes? When the stumble happens do you get a "SES" light, even briefly? Did you scan it?

Okay the sum total of my megar understanding of EEC is the ECM has two types of things it does:
1.) Operations it controls.
2.) Sensors it monitors for info to make control decisions.
If the trouble is a malfunctioning part that is not in either of those departments than you would not likely get a "SES" light & a DTC stored in memory, unless the part is related to something in either #1 &/or #2.

Your problem could be that water got to the injector connections, I can't remember if they had water-tight connectors. Or there could be a water induced problem and another part failure happening at the same time. If water got down the plug holes that could be the source? If water got to the coils then that could do it but it's hard to say where the water got to. From your description it seems as if this is random...like the water is doing the deed. I have a scan tool BUT I don't have any software for a OBDII set up. I whish I could give you a better input...if you need extra hands shout at me & I'll show up! Just a shot in the dark...how is the fuel filter? On my car the one from BG was still in it after 15 Yrs!!!! along w/plugs & a/f & pcv's!!

:thumbsup:
Tom
Oh, I'm just a rookie too, so I can't say for sure that I can do any thing but try to assist you....if I had the answer I'd fork it over...but I'm willing to help ya if ya want another body. I'm sure one of the senior guys will be along to show you the light...I know that for a fact!!

[BBBAD94ZR1]

Thats for the input guys, Tom no codes, no engine light, strange.....
I called Halibek and he said change the plugs, what do you think?
Looked at the plug holes dry. I suspect water also, the owner hosed of the engine[-X put it in the trailer and it sat for two days in -10 degrees[-X . I also fell sitting for 8 months and just getting started to operation temp does not help either.
The fuel was half a tank and I filled it up.
Im gonna change the plugs and go from there.
If the problem persists Ill give ya a call.
Thanks
RAY

[tomtom72]

Hey Ray, I defer to Mr Haibeck!!!!! :worship:

Yea look man I offer any help I can give ya, which ain't much 'cause I don't know much...but PM me if you want another rookie to lend a hand in person! It seems to me that plugs are cheap & why not give'em a shot. I wish I knew what Mr. Haibeck forgot about LT5's:o

PM me if you need to....don't hesitate.

[BBBAD94ZR1]

Well today, I changed the plugs and oil. Took it out and the same conditions. I also noticed at idle the throw out bearing makes some noise.
When you push in the clutch it goes away. Can you grease it and has anyone ever seen this before on a low mile car. I guess sitting it the worst thing for these car.

Any ideas?
RAY

[tomtom72]

Hey Ray, Sorry I didn't know about where you lived or I would have for sure given you a shout & stopped by on my way home! It would have been cool and I would have brought my tools!

Now on to the business:

Did you change the fuel filter and then do a fuel pressure test following the Helms manual? If not, swap out the filter...autoZone has them...and do a pressure test. I can't say for sure that is the root cause but the FF is easy to change. Oh, you do have the Helms manual, right?? If you have access to a scan tool it would be good to do a reading with the motor running in "open loop" and "closed loop"...I kind of learned how to interpret that data when I needed new injectors.

Stupid Q...does the car miss as soon as you start it or does it take a few minutes before the miss becomes evident and does it get worse the longer it runs???

The "noise" from the trans/clutch thing...when you step on the clutch you hear the noise? If yes and you pop it to the neutral gate and let off the clutch you still hear the noise?? Usually the T/O bearing makes noise only when the clutch is depressed and usually the noise quiets &/or leaves when you are off of the clutch, either in gear & moving or in neutral.

Don't feel bad about this...I have a theory about low mile virgins, like yours & mine...the worst thing is for these cars to sit and then be used...it causes more problems than if you just use them every chance ya get...screw the milage! My car came to me w/8,000 miles on it and I had clutch hyd. system problems after I drove the son of a biach to BG & back. I swear the car thinks I'm a slave driver!

Look man here's my digits...914-663-1201...use'em if ya need to...feel free...you are not alone in this and we are a tight group, we don't leave any one behind!

:thumbsup:
Tom

I think the noise you are hearing from the tranny/clutch with the pedel up is the dual mass fly wheel...especially with a miss, it sounds real swell!

[tccrab]

Well today, I changed the plugs and oil. Took it out and the same conditions. I also noticed at idle the throw out bearing makes some noise.
When you push in the clutch it goes away. Can you grease it and has anyone ever seen this before on a low mile car. I guess sitting it the worst thing for these car.

Any ideas?
RAY

Ray:

When I picked up my '90 last March (almost a year ago, gosh how time flies!!), it too had an issue of the throwout bearing making noise. Didn't happen all the time, and would go away as soon as the car warmed up, or about the 3rd or 4th stoplight. I figured if it didn't go away, I'd eventually have to drop the transmission and replace it. I guess I got lucky, because it eventually went away. I think it just needed a little exercise to limber up some stiff joints. :wink: Truth be told, it was probably some corrosion or a burr that eventually got smoothed out.
My car, like yours, sat for most of her first 15 years. It only had 9700 miles on her when I bought her home. It was stored in a climate controlled shop and received the appropriate care, just didn't get driven all that much.
These cars just need to be driven. Often. And they seem to like getting their legs stretched once in a while. :-D

TomC
'90 ZR1 #792

[BBBAD94ZR1]

Thanks for all the input so far, for the record my plugs were pretty black.
Would it be safe to assume my injectors may be dumping to much fuel and loading up after being driven above 4500rpm? Does anyone know a good lt5 tech in NJ. I spoke with Tom Tom and he suffered fRom the same crap.
I also found out the trans rattle is from the car missing and the flywheel weights banging around. Well Im going to get the car scanned in two weeks and see whats going on with my injectors etc.:icon_scra :dontknow:

Any other input is well appericated.
Thanks
RAY

[tomtom72]

Ray, just to give you the BMW part number on the oil for the MN6/ZF6:
P/N = 07-51-0-009-420
Description = oil, 10W60
cost = $8.95 per liter, Westchester BMW price, plus s/s tx.;)
Fill = approx 2.2 liter, maybe a bit more...till it runs back out of the fill hole. Three liters for the first change, two next yr., etc...

I think scanning with a service bay diagnostic scanner will point to the trouble. I think if an experienced Tech sees the data the diagnosis will be evident. Plugs should not be black, brownish color is what book says. OBDII has the ability to do a cylinder balance test and I think that along with the fuel numbers will point the way to the source of the trouble.

A good guess based on the facts is either a vacuum leak the size of the Grand Canyon or there are some injectors leaking due to not closing fully.
Otherwise why would it storm @WOT and part trottle = miss.

Good luck & if extra set of hands needed, you have my #.
:thumbsup:
Tom

[BBBAD94ZR1]

Thanks for the info Tom, here is an update guys. I drained all the gas out of the tank and it looked ok. I put in some ultra 94 and the same crap.
The miss was the same, I had the car in the garage and was reving the engine up to around 3500 rpm and it was missing kind of stumbling, it was also spitting out of the exhaust. The car broke up everytime I did it. You could also hear a slight miss at idle. Does anyone have any other advice for me. I seems like a injector issue 2 me.
Im going nuts here. Please advise.:cry:

Thanks
Ray

[WB9MCW]

I still suspect the fuel pump(it very well may be the injectors are shot but lets check the fuel psi first)...do the psi test on it and change the ff like tt said.... next will be the ohm's on all 8 injector readings....go to this site for ideas and pic's..plus jeffvette is good at zr-1 diag. so work with him on it but be sure to do steps one at a time and keep reporting here what you find as u go! Here is the PNW ZR-1 site url... We all know how you feel right now but not to worry the brotherhood will get you through these times. Right BlackJack!!!

And I quote the master!!!

LT5 Top End Tear-Down

By:

Jeff Flint - Washington State Director/ZR-1 Net Registry
Robert Melbo - Oregon State Director/ZR-1 Net Registry



Looking under the open hood of a ZR-1 can be a scary proposition. Lines run every which way and the possible expense of a misplaced screw or broken part can send shivers down the spine. What looks to be a nightmare is actually quite simple in reality. Part 1 will look at the removal of the top end, while Part 2 will focus on the cam covers for refinishing to bring new life to the engine.

http://www.pnwzr1.net/:thumbsup:

http://www.pnwzr1.net/Registry%20Project/9.JPG

http://www.pnwzr1.net/Registry%20Project/9a.JPG

[blackjack]

right on:)
blackjack

[tomtom72]

Jez Ray, bless you for draining the tank! Go buy a fuel filter and use that to get the wrench size for the nuts on it and the lines...I don't remember if they are the same, sorry. Swap the filter, and do a pressure test alla the book flow chart or see Jeff's answer to Nate(sick 90) for a simpler way.

Gotta start eliminating places to look. If the fuel sys check out then ing sys is next on line. I would still say that if the fuel sys checks out okay I would borrow a scan tool and "look" at what the motor is doing. You can take out all the plugs and turn the key to "on" and smell all the plug holes...if the injectors are leaking you might smell the fuel or just turn the key on for a short time and then pull the plugs to see if gas is present. Obviously it shouldn't be and the injectors are leaking.

:thumbsup:
Tom

[Demps]

Before you go crazy:

Did any of the stock plugs have the platinum tip missing from the ground? This will effectively increase the gap. What did you gap the new plugs at?

Ted

[BBBAD94ZR1]

Plugs were ok, they were black, changed them with 419's and gap is 45.
ray

[Demps]

Ray,
Wish I were closer. I had a car once that sputtered on throttle tip in. It was the plugs. If it were my car, I would re-gap the plugs to .035 and see if it makes a difference. It is free to do so if you take your time and properly remove the plug boot. Is the 419 the dual platinum? If so, get rid of them!!! The platinum puck will fall off. Ted

[BBBAD94ZR1]

ok what plugs would you suggest.
thanks
RAY

[Demps]

I've been lucky to find Rapidfire #9s. My yellow car has the expensive Iridium plug and it's good for what it is. #9s are about $2 each and go strong for about 10,000 miles. Ted

[BBBAD94ZR1]

Plugs I put in were 413's not 419's regapped and same issue.
RAy

[Demps]

I hate to be the one to say it but get the Helms manuals.

Does the car act the same when it is cold (first started) and when it is hot (over 120 deg F H20 temp)? (o2 sensor)

Go buy a fuel pressure gauge with a drain hose on it. Connect to the schrader valve on the fuel rail on the passenger side front. (filter)

The manual references fuel or spark--which everyone else has. Could be the spark plug wires are broken down or damaged. Measure the resistance across the plug wires (boot to boot):

8/5
1/6
4/7
3/2

[BBBAD94ZR1]

Thanks,
I have the books, I will do this next week and let you know my findings.
RAY

[BBBAD94ZR1]

I got the Z happy again :-D , I took it to the dealer the Rick recommended flushed the injectors 3 times, changed the fuel filter, and new plugs again. Two of the plugs fouled out from the injector cleaner. The car needs new exhaust the resonators are making noise when downshifting. Think im going for the B and B. What do you think?
The car now runs and idles perfecto! I did the nickel test and it works. I want to thank all of you for support. I also got pulled over twice on the way home from the dealer.
The cops pulled me over for no inspection sticker and after I explained the situation they were cool and commented on the car.
You are a great bunch of people.

Thanks again....
RAY:worship:

[tomtom72]

=D> :mrgreen:

Glad it was that simple Ray!!:thumbsup:

[WB9MCW]

now u is da man mr ray in the baaaaaaaaaaaaaad 94 zr-1.........................

[blackjack]

pedal to the metal
blackjack

[john k]

Happy your car is runng well glad we could help.
if you need anything else dont hesitate to call.
john

[tomtom72]

Ray, mind if I ask a Q? What exactly was this "cleaner" & how was it applied??

thanks for any light!

:mrgreen:
Tom

[BBBAD94ZR1]

Tom,
The cleaner was applied directly to the injectors and the fuel supply was cut off. The car only ran on the injector cleaner. This process was done three times. I seems to have worked pretty well and saved me 2 grand on injectors and install. The gm part number is 58cpcr3 and a can of Bng injector cleaner in the fuel tank to clean out any carbon deposits.
Thene finally a set of new plugs part number 5614355 /41-913 plugs gapped .50. The car runs so smooth the nickel test actually works.
I will try to post a video of this.
RAY=D>

[tomtom72]

Thanks Ray! You had this done at the dealer?? sounds like a very specialized cleaning process.

anyway glad you saved the $$$!!!:mrgreen: