Hello all,

New to the forums, but not to the below problem. Any help would be greatly appreciated. Here we go.

I have an 89 with 3800 miles in pristine condition. Recently I started driving it again and have been having several issues. Upon pulling it out of storage I was getting variable idle after the vehicle warms up. The dealership replaced the ECM and changed out the whole ignition system. Everything was working great for a few weeks. Then i was driving one day and the thing cut out on me for no apparent reason. I tried starting it and nothing no go. It will crank all day but wouldn't start. BACK TO THE DEALERSHIP. We drained and cleaned the fuel tank tested the fuel pump and filter. We are getting fuel pressure at the rail to GM spec. So I started driving again and the same thing, just cuts out and it won't start. Once the car cools down it will fire right back up again on the first crank. Not sure what is going on. The deal is wanted to change all the fuel injectors. I'm a little leery due to the fact that how could all injectors go bad at the same time. I know the car sits but we always put stabil in it and at least emptied the tank every spring by driving it. This only happens when the car has warmed up. Again once it cools it fires right up. Dealership is just as puzzled as I am. Any thoughts would be great.

Thanks.

 

You could simply have one sticking open and flooding it
Those old multecs....step up to some Bosch better design can handle todays fuels. Do NOT waste your money on cleaning/rebuilding just put them in a box.
Best thing to do is check the ohms on them when the engine is HOT then decide if thats what you want to do. Sounds like they are throwing parts at it.,..suppose with the low miles maybe its worth it . They can work ok when cold then start going wacky once hot

Post up some pics !

 

You think that it's possible that all of them are going bad at the same time. I would be more inclined that it would sputter do to one or two fuel injectors are sticking.

 

Your assessment is correct for vehicles that have a sequential fuel injection system. You Vette is batch fire if one injector shorts it will disable all of the injectors.

 

That makes more sense now. I just want to make sure it is not something else that we should look at before I drop 300 to 500 dollars on this thing and still end up in the same place.

Thanks.

 

Did the stealership change out the ignition control module? When they go bad they are affected by heat and go out, then after the car cools down they seem to work again. These are hard to bench test because of the no heat condition after they are removed from car. Also get a noid light and check your injectors before letting the idiot's at the dealer sell you a injector R&R make them show you the readings, Then call Jon @ FIC,
$300 - 500 will turn into $800 - 1000 if you have the dealer do it.

 

If you just want to throw parts at it I would put a ing module in it and a fuel pump in it before I did injectors. Although you had fuel pressure when it got to the dealer to test it does not mean that the pump did not heat up and stop working this is pretty commom. Injectors would be the last thing I would replace on a car with that low of millage unless I knew they were bad

 

Make sure there is THERMAL grease under the ignition module inside the distributor. The modules get very hot and will go into failsafe mode (turn off) if the proper grease is not used. Some people use dielectric grease by mistake (or none at all).

 

Multi tech injectors do fail. They do not tolerate corn gas, mileage is irrelevant they have been living in it for many years.

Suggest ohm checking the injectors before guessing & "throwing parts at it".

Some injector check info in this thread:
http://forums.corvetteforum.com/c4-t...-concerns.html

 

I had Gm change ignition module last year only 54 miles since they changed it. I like the suggestion about calling Jon @ FIC. We'll see what the cost is. Will have to take manifold apart to replace or can they just pull the injectors and replace?

 

Plenum and runners need to come off fun stuff. Replace the orings on the fuel rail also once disturbed (old age) they have been responsible for more than 1 C4 fire. Should come wiht the Fel Pro TPI gasket set.
These have a tendency to leak from the rear wall of the base intake once stripped down you got an opportunity to see if you need to pull the base off or not. Hopefully not.

 

I called FI yesterday, Jon was with a customer so Kyle ended up talking to me. Real nice guy. He basically told me that he has been changing out alot of Fuel injectors and been selling them new TPI diaphragm and spring kit due to the added ethanol in the fuel. The ethanol causes the internal parts of the injects to rust. So the replacement kits are designed for the new fuel of today. So for a complete rebuild kit it comes out to be about $480 + shipping.

I'm probably mid level experience as far as mechanically able. I've changed brakes and radiators on other various vehicles. You think this is a pretty easy switch. Do we have any tutorials on this?

Thanks guys for all your help.

 

So I figured it would cost me about $900 to do the work with parts. I'm thinking of waiting till next spring. This way it doesn't sit again. Thoughts

 

there are so many tests that can be done before you throw parts at it. install a fuel pressure gauge on it for 40 bucks see what the fuel pressuse is when it dies. carry a spark tester with you see if you have spark when it dies. You could throw parts at it for months and not get it fixed

 

agree with hooked. If you have a fuel pressure tester, you can use it with any car, and since all of them being made now are fuel injected, you will have a dynamite test tool.
I also think it is the ignition module, but you have to check the spark when it quits. not a fun thing when you have one of these cars because of the tremendous underhood heat. I would set yourself up in advance, remove the spark plug wire plastic ring on top of the distributor, and when it quits, just remove the first plug wire you come to on the distributor, and slide in a spark tester.
It could also be the ignition coil.
If there is no spark, you can always take the ignition module to autozone or O reiley's and have them test it. bring along your wife's hair dryer and get it good and hot while they are testing it. if it is heat related, it will quit working right in front of you.

 

Classic of low mileage garage queens. (no 'fence intended)
Age takes it's toll on so many parts that would otherwise not be a problem.

IMHO consider your car to be twenty years old, not just 3800 miles old.
Seals, rubber parts and fuel system components are subject to the same degradation with regard to age.

 

Where in the world did you get THAT number?????

a set of Bosch-III injectors with gaskets and O-rings for the rails sells for about $250 from FIC

the regulator diaphragm is about $75

Its a 4-6hr job for the first timer.

BUT, when you ADD the cost of a FSM set to that, you now have spent less than $500.

And believe me, and everyone else will agree, you NEED that FSM.

It tells you how to save your money and STOP paying a STEALERSHIP that has NO C4 techs to work on your car. They got next to you on the ECM...Jeeze. That was a crime.

Find a local Corvette club and join. They will know who you can trust to work on your car if you do not want to.

IMO, your problem is fuel injectors. get a dvm and ohms test each inj hot and cold. if you see ANY at less than 14...they are junk.

Has ANYONE looked at the harness ? Age is a problem, not miles. Plastic insulation dry rots and strange things happen,...

Inj swap is cake walk. Read the thousands of threads here and go to You Tube for MANY videos on C4 inj swap. FIC also has lots of stuff there.

 

I would not throw 500.00 worth of parts at something and hope it fixes it. Test test and more test. it is not hard to find the problem if the car is acting up. fuel and spark are easy to check if you do what I and coupguy said.

 

I had the fuel pressure checked and also the spark. Everything checks out. As far as the price. I called (FIC out of Georgia) and this is what they priced me...

New 22lb delphi FI $399.00 E-10 compliant
Fuel Rail Kit $30.00
TPI Diaphram & Spring Kit $50.00

Dealship labor was around $375.00.

So I figured other misc. Expenses comes out to be around $900.00.

I could do it myself and watch the video I just am a little intimidated due to the fact that it has such low miles and I don't want to create a bigger problem. The goal is to get it running right so I can turn around and sell it.

Now I might be asking a stupid question but what's a FSM (Assuming Factory Service Manual)

Lastly, did the photo's I posted come up. Should be under My Corvette Photo's.

 

After it dies, pretty easy to check for spark. If it's there, you've eliminated the ignition system. If it's not, start at the distributor and work forward.

You already said you checked fuel pressure and it was fine. Even if the injectors are bad, it's HIGHLY unlikely that all 8 failed at once. Even if they do, the car will still run. I picked up a used '90 L98. As soon as it went closed loop, it ran....rough....but it was still very driveable. 7 of 8 injectors tested at 8 ohms or less. So, check the injector impedance but don't count on injectors fixing the issue.

I would check for spark when it is dead and check the fuel pressure. Once you know which element is missing, continue to trouble-shoot that system.

Frankly, I would not be surprised if the ignition module has failed again, likely due to a lack of thermal grease as Cliff mentioned. If it's bad, you'll have no spark while the no-start condition exists.