me: Long time gear head, mostly pre-computer cars. 59 Studebaker Silver Hawk, 62 Stude GTO Hawk, 64 Mercedes 220 SB, 72 Porshe Targa, and I breed VWs in my back yard. I mostly restore, not a hot rod guy.

Purchased my C4 (actually my wife's) about 2 years ago. Looks good and runs good, until a few weeks ago. I just moved and am living in an apartment without my tools. I drove the C4 to my new location (5 hour drive) and about half way it lost power. Cranked but could barely move the car at idle.

With no tools, I had the car towed to the Chevy dealer (1st mistake). $1500 later they say its fixed. They replaced several items that made no sense and ECM, could have been that. Cranked, ran fine for about 5 miles and it died. Would not crank. Back to the dealer (2nd mistake). $600 later, new EGR, another ECM and a claim that the wiring was causing erratic signals to the ECM (a rat in the car per the mechanic). Said he chased to problem the TPS and water temp signal. They offed to "try" and fix, but the car is NOT going back to the dealer. Now the car cranks, idles ok but runs poorly under power. Like a cylinder or 2 are missing. Ran better before the 2nd dealer trip.

Enough background. I can borrow tools, FSM is packed somewhere but I'm ready to go. After reading lots of posts I ordered TunerPro software, ALDU1+CABL1 hardware but have not received it yet.

To me, the car acts like a problem with the TPS. I measured, .6 V at closed throttle, 4.6 WOT. Measured at the TPS, not sure where to check at the ECM. Found 1 nicked wire at an injection, fixed that but it made no difference.

Looking forward to help from you corvette folks. I get most of my information on my other cars from forums. I will post as I go.
Please - ask questions, give opinions.

dell

 

Can you give us some background on the car:

- Year
- Transmission type
- any mods

If I read your post correctly, you were driving the car (it was fine) and then it "lost power". Does that mean it was still running but badly, or does that mean it died and would crank but not restart?

Oh, you are correct about not going back to the dealer. With rare exception, Chevy dealers are not very good at handling cars that are a couple of generations back, in my experience.

 

What year C4 it makes a difference.

Crossfire, l98 mass air flow, l98 speed density, LT1 speed density, LT1 or 4 mass air flow?

First impression = plugged cat converter(s).

 

1991
automated trans
stock L98, TPI, no mods to my knowledge

first time, it lost power but would crank and idle. Just enough power to move car at idle. Push the pedal just a little and it died.

Second time, it lost power for about 10 minutes (enough to get it off the road), then died and would not recrank

 

Usually a motor with those symptoms will throw a code.

 

Back at the car. I would expect a code.

What terminals provide ECM codes? I though it was A to B, but with A B jumped, the fans run when the switch is turned on. Hope I did not screw something up.

 

It sounds like you may have a few bad injectors. Have they ever been replaced? If not, that could be your problem. Check them with an ohmmeter hot and cold. I recall that anything not near 16 ohms is bad.

 

Do you check resistance with the electrical connectors installed?

 

I unplugged the injectors and checked resistance. Engine is cold.

is there an explanation? other than needs rebuild/replace?
1 - 16.3
2 - 0.2
3 - 6.9
4 - 11.3
5 - open
6 - 16.4
7 - 7.5
8 - 16.4

If anything other than 16 is bad, how did the car run at all?
Who makes good injectors?
Any good test/rebuild recommendations?

 

Until I read your last post, I was thinking fuel pump issues. Assume you've already checked pressure and leak-down?

 

have not checked fuel issues, but seems like I need to start with new injectors.
looking for advise on replacements or a good test/rebuild vendor.

Also, isn't terminals A to B the correct terminals to read codes?

 

Fuel Injector Connection

Jon is the owner. Call & speak with him personally.

http://www.fuelinjectorconnection.com/

Nuff said.

 

Top, right 2 terminals (next to each other) are A and B. Jump those to read codes.

 

Terminals A and B, top row, right two terminals. The ones that have A and B written on the top of the terminal plug.

I paper clip those terms, switch on the key and ... the radiator fans come on ?? The dash lights up normally. I pull out the clip and the fans go off.

Does that make any sense to anyone?

 

I have a 90 and a 91. Both ran with bad injectors but crapped out under acceleration. When they got hot, they would not even idle. Check the posts in this forum. I recall someone last week going through the same problem you had with taking the car to the dealership. From my experience and reading this forum, to the mechanic unfamiliar with this issue, the "cure" has been an unnecessary tune-up and/or replacing the fuel pump -- neither of which solve the problem.

 

I had three injectors go bad and Jon was a great help. The injectors should read between 10 and 14 ohms. Either side of those readings is bad

 

Jon recommends:
new Delphi injectors that are stainless steel.
Or rebuilt Bosch 3 injectors.

Any opinions? I sure like the price for the rebuilt Bosch

 

I and many others have bought the reman Bosch III that Jon has. I have not installed mine yet. There are a lot of threads on here from members that have and they all seem very pleased.

 

yep, my book saYS whenyou do that, fan is suppoed to run,,thats one way to check cooling fan motor.
You have an OBD 1 system. A is the ground terminal and B is the diagnostic terminal.Key on, engine stopped.code 12 flashes 3 times, then the code. wjhich will flash 3 times for each code.A and B are in the right top corner of the ALCL, reading it RIGHT to LEFT is correct way ( top terminals read (looking straight at it) FEDCBA, and bottom reads normal, ie, GHJKLM. good luck,.

 

OK. Here's the story to date. It's ugly. The chevy dealer in Knoxville on Parkside Drive is, well fubr.

Removed the throttle body to get to the injectors. There are three hose connections that are broken. Four including the hose to the drivers side PCV valve. It was spit over 1/2 way around. One of the t50 screws holding the drivers side intake is broken. There is a hose missing to the EGR switch (not sure what supposed to be there, I'll include a photo). The water hose connection to the throttle body was bulged at the TB. The hose is paper thin.

I am not saying the dealer mechanic broke all this stuff, but how can a mechanic but the parts back together without fixing this stuff !! He replaced the EGR valve, so he had to see most of these issues.

Injectors are filthy and several o rings are cracked. Interesting they wrote on the invoice that they checked the injectors and they were fine.

OK, off my soap box.

Thanks to all who gave me suggestions. I'll post how the car runs when I replace the hoses and injectors. Not done yet.

Corvette forum rules. More knowledge than a dozen dealers.