Hard Start/No Start Troubleshooting Log

[vigman]

Hmmmm must be different in 89

That's the scoop on my 88....from the factory shop manual.

Good luck

 

[MNSIU]

Starts/won't continue to run.

I sure hope this problem is figured out. I have an 89 with 32000 mi on it and it sounds a though it has the same problem. Car starts right up, runs for a bit and then shuts down as though someone has turned the key off. The car may or may not start right up again. Come back in half an hour and I can start it up and go through the same thing. Injectors?

 

[milehigreg]

And we have a winner!

Went out to the garage last night. Disconnected the electrical connector for injector number 8. Said a prayer. Inserted the igntion key. Turned and released. She cranked, fired and RAN!!!! :J


Totally motivated now to tear into the plenum and intake and get the new injectors in.

MNSIU - Get your mulitimeter out and check the resistance of the injector coils.

 

[MNSIU]

I'll do that and thanks for the heads up. I am guessing that once the injectors are out you measure the resistance between the two points? 16 ohms? (I have never checked injectors before. All my previous vetts have not had them)

Thanks again and I'm glad you found your problem. MNSIU

 

[geekinavette]

Went out to the garage last night. Disconnected the electrical connector for injector number 8. Said a prayer. Inserted the igntion key. Turned and released. She cranked, fired and RAN!!!! :J


Totally motivated now to tear into the plenum and intake and get the new injectors in.

MNSIU - Get your mulitimeter out and check the resistance of the injector coils.

Allright a positive note!

 

[Toms007]

Went out to the garage last night. Disconnected the electrical connector for injector number 8. Said a prayer. Inserted the igntion key. Turned and released. She cranked, fired and RAN!!!! :J


Totally motivated now to tear into the plenum and intake and get the new injectors in.

MNSIU - Get your mulitimeter out and check the resistance of the injector coils.

Great news Greg! I was hoping that you would find it soon.

 

[milehigreg]

Thanks Tom and Bill.

MNSIU - You don't have to remove the injectors. Just take off the electrical connector and check between the terminals. Let us know what you find.

 

[vigman]

Two Words

WOOOOOO HOOOOOOOOO

Great news

Vig~

 

[MNSIU]

Greg, GOOD NEWS! I found #8 injector only read about 11 ohms. The others were almost all the same at about 20 ohms. I pulled the connector off of # 8 and the car started right up. I let the engine get up to 194' and it still continued to run. I figured that if this was indeed the culpret I would plug it back in while the engine ideled. As soon as I did the engine quit. May as well change all of them while I have it apart. Is there any pictorials out there that walk a novice through this? Thanks for everyones support and suggestions.

 

[milehigreg]

Greg, GOOD NEWS! I found #8 injector only read about 11 ohms. The others were almost all the same at about 20 ohms. I pulled the connector off of # 8 and the car started right up. I let the engine get up to 194' and it still continued to run. I figured that if this was indeed the culpret I would plug it back in while the engine ideled. As soon as I did the engine quit. May as well change all of them while I have it apart. Is there any pictorials out there that walk a novice through this? Thanks for everyones support and suggestions.

Go to thirdgen.org and look for an article called TPI Injector Swap. While not specific to Corvettes it contains a pretty good explanation and some pics. You will need a 17 millimeter flare nut wrench for the brake booster vacuum connection to the plenum. Ask me how I know!?

 

[MNSIU]

Go to thirdgen.org and look for an article called TPI Injector Swap. While not specific to Corvettes it contains a pretty good explanation and some pics. You will need a 17 millimeter flare nut wrench for the brake booster vacuum connection to the plenum. Ask me how I know!?

Greg, thanks again for the article site. It will come in handy... Ok, I'll bite. How do you know about the flare nut wrench?

 

[milehigreg]

Greg, thanks again for the article site. It will come in handy... Ok, I'll bite. How do you know about the flare nut wrench?

It is actually a 16 millimeter flare nut. The one on mine is stuck tight. I ended up disconnecting the hose from the steel tube and removing the plenum with the tube still connected. Tricky! I hope to be able to get it off while the plenum is on the bench. Easier to put back togehter that way.

I spent about two hours last night getting everything off the top of the engine. Takes some patience. Some of the torx head bolts are hidden down underneath the runners. Two of them were loose and one is even missing. I can't believe I didn't have a vacuum leak!

Here's a tip. Take the gas cap off before you disconnect the fuel lines from the fuel rail. My car hadn't been on for days but there was enough pressure in the tank to push fuel out. Lot's of fuel. As soon as I loosened the cap, no more fuel.

There is a sensor attached to the thermostat cap with a bracket that just kind of hangs in the air above the intake manifold. Anybody know what this is? I think the MAT sensor is the one in the back of the plenum.

Tonight, I clean! :crazy

 

[milehigreg]

Step by Step

Injectors arrived Friday evening but still waiting on new EGR and FPR. So, :eyerole I CLEANED. Cleaned up the plenum and runners. Soaked them both and got all the oil and gunk off the inside as well. Of course, the same gunk that was in the runners is in the intake but I have to draw a line somehwere. Cleaned the throttle body and removed the IAC vavle so I could clean both the valve and the passageway. Cleaned the top of the intake and where it bolts into the cylinder heads.

The article in thridgen mentions taking this opportunity to tighten the intake to cylinder head bolts. I would like to do this but I'm a little scared hnoes about stripping the threads in the aluminum heads. I have a torque wrench. Should I go for it?

Here's a tip - the tiny vacuum hose for the EGR and the EGR solenoid is VERY brittle. Mine broke in three places just disconnecting it.

 

[jmur61]

Similar Problem

milehigreg,
My 84 Vette started doing something similar. I would drive it to work. But after leaving it under the sun in the parking lot all day I would try to turn it on but it would not (it would just crank). I would leave it at the parking lot overnight and the next day I would get a ride to work and go to my car and it would turn on and stay on. I would drive it back home, and get a ride back to work. I work only 5 miles away from home. (This went on for 3 days)
The last time was 3 weeks ago. I drove it to work, and as soon as I got off the Freeway, 3 blocks away from work, it died. I pulled over (with momentum) to side walk and tried turning it on but it would just crank.
I had it towed to my house.
For 3 weeks every other day in the mornings it would turn on. But I would not drive it to work, I have been borrowing my brother's 2nd car.
2 days ago I did the same routine of seeing if the vette would start and I got a different symptom.
Now the only thing it does is: trrrrrr, trrrrrr, trrrrr. No cranking at all.

I think that the new symptom has to do with the starter gone bad.
(How far off from the truth am I?)

 

[ap_g35c]

I posted on this thread a couple of weeks ago about the exact same problem. Since Greg determined the problem was a fuel injector, I tested mine and found that it was bad. Sunday evening I pulled the engine apart, down to the fuel rail, popped in the new injector, reassembled everything and BOOM. The car is running perfect now. $45 dollars and four hours later.

MilehiGreg: Thank you for sharing your experience with others, because of you I was able to save hundreds of dollars by diagnosing and fixing the problem myself.

Everyone else: Thanks for all of your suggestions and helpful comments, to the situation.

It feels so good to drive my vette again.

 

[Toms007]

It's good when a plan comes together!

 

[milehigreg]

imur61 - I think you have a completely different problem. An issue with the start circuit. A service manual is an invaluable tool.

ap g35c - Man. You have about one tenth of the time and money invested in fixing yours . BUT, I have a new fuel pump and strainer, new ecm, new ignition module, eight new injectors, a new FPR and a new EGR. Knowing this takes care of the money spent. I learned a ton about my car. That helps with the time spent issue. The biggest problem is being without my Vette for two months!

 

[jmur61]

Start Circuit

Thanks for your reply milehigreg,
I kind of thought that my problem was different than yours. I have a service manual that I got from AutoZone but it doesn't say much.
Which manual would you recommend and were do I get it from?

 

[ejball]

Helminc.com Sells the original GM version -about $140 - you get all 3 GM service manuals for a 1988 anyways - they have our year of vettes as well as many others. Also, you can find them on ebay quite often. But this is the one you want it is the official dealership version.

 

[Toms007]

I agree Helm manual the only way to go. I bought mine on ebay.