hello corvette people ! It's been a while since I posted in the forum because of computer problems ! but I need all your help that I can get !!

my 88 vette has always been , you have to give it several times to start ! maybe the first try will start but sometimes you have to try 3 times or more but it never buged me !! and never known what it was causing this :confused: sometime I will get a bit ashaimed !!

about 3 months ago my vette was having some idle problems !! when it comes to normal operating tempriture ,the idle goes down to 500RPM and some time 400RPM :sad: and as well , I never known what was causing this !!

Now the bigest problem of all !!!

when I am driving my vette and than I will leave the gas pedal it just dies !!
but It just start up when I try to start it !!! with no missfires ,no engine problems and no SERVICE ENGINE SOON light !!!

just a remainder that all of these problems are all still existing !! and don't know how to fix them :confused: so please help me because I don't know where to start from

thank you
marlon
:flag

 

I sounds like a MAF sensor problem. Try unplugging the MAF and see if it runs any different. Check for codes. Repost the results.

 

I had a similar problem a while ago with the near stalling if I didn't give it throttle. Turned out to be the IAC valve. Good luck.

Also, I just recently had the main cat replaced. The seemed to help a little with my idle too.

 

Ok thanks !! now I will go to check ..... just I want to say that I asked my preaveus owner because he is a friend of mine and he said that the starting problem has been there for a while , even when it was his !!!! :confused:

 

I just fixed an idle problem by replacing my IAC valve. Mine wouldn't idle at all until I drove about a mile or 2. Even with the vette at operating temps, if I shut it down and restarted it it wouldn't idle until I drove a little. I even set a code 33, but this all turned out to be the IAC valve. It was pretty easy to replace.

 

First thing, check all the sensor connectors and harnesses. If one has worked itself loose, it will cause these problems. There is the coolant temperature sensor on the block under the TB which if it disconnected, will not allow the car to start. Also the IAC connnector and TPS connectors get old and fall off.

I wouldnt replace the IAC until you have checked everything else. I would tune the car up COMPLETELY, plugs, wires, air filter,Cap, rotor, check hoses, belts, timing, fluids. Check all vacuum lines.

Then clean the TB and follow the tech tip for idle reset. Check for codes. If it still has symptoms, look at MAF, then IAC last.

Also check for gaps or leaks in the Air filter housing, ducts causing false air.




[Modified by GusBustamanteJr, 6:11 PM 2/11/2003]

 

Sure wouldn't hurt to check your fuel pressure, too.

 

Two years ago I flew to San Jose to pick up a 88 with every factory option made and only 26k miles all for $13,000. The car liked new and I took it for a 20 minute test drive and it drove like a new car. I bought it and on the ride back to Arizona and coming off the first exit ramp it stalled. I then realized I did not test drive the car enough to get it up to operating temperature. It was also difficult to start when hot. Anyway, I drove it like this for 4 or 5 local drives after which I would disconnect the battery (have the battery quick disconnect switch ), Then on about the 6 drive it never did this again. 2 years later it starts and runs perfectly. I only way I can explain this is that disconnecting the battery several times might have made the IAC piston run up and down its cylinder to re-calibrate itself (as well as the computer doing this) and this might have freed some gum or whatever that was making the IAC piston stick. It is reallt great when a car fixes itself and just maybe this will work for you.
I understand that there was a recall for the MAF and the relay (not sure what it is called some burn-off relay??) next to it causing this problem also. IMO this 88 Z51 is the best handling Corvette I have owned or driven in and I drove most years.

 

:withstupid: Same thing here! I had some what the same problem for at least 4 month's!! Turned out to be my IAC (Idle air control valve) if you dont know what IAC means. hope this helps with your problem. :thumbs:

 

I had the same problem bugging me for about three four months. My car would only stay running only if I had my foot on the gas. I fixed it by cleaning my IAC valve and readjusting my IAC. The easiest way to do this completly removing the throttle body from the car. Use a cresent wrench to remove the IAC (couldn't find a socket to fit it ) . I used carb cleaner to clean the pintle on the IAC, then I measured from the mounting gasket to the tip of the pintle and I was at 1 3/4, my book says it needs to be at 1 1/8. To do this I just simply turned the pintle like a screw to the required measurment. While I had the throttle body off, I went ahead and cleaned the back side of the throttle body. Use a tooth brush and carb cleaner so you won't scratch it. Put on a new gasket and now my car idles. Even better than before. It is recommened that you clean your throttle body at every 30,000 miles. Hope this helps you cause your problem sounds like mine and I have an 87 coupe :rofl:

 

Hi guys - I'm an ASE Recertified Master Tech / Advanced Driveability Specialist... Here's the "long and short" on the issue:
It sounds to me like a "min air rate"issue - the airflow past the throttle butterflies should be just enough to sustain a fully warmed up idle without the help from the IAC system. What this means is that with the IAC passage completely plugged, you should be able to sustain atleast a 550 RPM base idle. The IAC system is designed to augment that base idle to compensate for additional load - put in gear, cranking the steering wheel hard, A/C load, cold start, decel... If the min air rate is too low due to a dirty t-body or base adjustment, the symptoms you describe will manifest.
Start by grabbing an old tooth brush and a can of carb clean, scrub out the throttle butterflies 'till immaculate, hold the throttle to the floor during cranking to "clear flood condition induced by carb cleaner", (point exhaust at unwelcomed bystanders!) blow out a huge cloud of acrid smoke, hold at 2000 rpm until "she smooths out" and slowly bring her back to idle. You may also want to remove the IAC and clean out the passages too.
If the engine still won't maintain a base idle with the IAC plugged (fully warmed up), you may have to kick up the min air rate by removing the small factory sheetmetal plug covering the base / min air rate adjustment screw (Torx T25)...
Driveabilty is a science in and unto itself - aspirin required in most cases! :banghead: :flag