I've had a thread like this before, but now I have more information, so maybe someone can help me, NOW! lol

Dispite my best judgement, I took my 1988 L98 TPI baby to Meineke. All I wanted them to do was run a diagnosis for what's wrong with my car. What I told them was:

Long start times (usually from cold state)
Engine sometimes dies after 1-2 Mins of driving
Black smoke comes from tailpipe, if I use the gas pedal to start the car
Rumbling noise beneath the car when I drive at slower speeds

So I take the car in at 11:00 and decide that I'll wait. At about 2:30, I finally walk up to the counter to see if they even TOUCHED it yet! They said, "Yes, and the mechanic would like to know if you could leave it for a while" Which pissed me off, because I could see my car sitting in the same parking space for well over 2 hours. So they took it, came to the conclusion that they'd need it longer, then didn't bother to tell me, KNOWING I was waiting.

You can see that I don't like them very much.

So anyways, they said nothing was wrong, but there was a service bulletin, which said all these things to do, since this is a common problem w/ the 88 'Vette. It would cost me $350 for JUST the diagnosis (gee, didn't I JUST ask for a diagnosis?) Needless to say, I didn't leave it.

So I get home, and find this thing online saying that it could be the MAF sensor realys.

It says I can replace the relays, and it may help out the problem. But here's the problem. It says that it's available as part number 14089936 from GMSPO. I'm a former Ford guy, so Iunno WTF GMSPO even stands for! I checked websites and none of them bother to tell me.

So my questions are if anyone has had these problems, which I listed above, wtf is GMSPO, and does anyone know where I can buy these relays? I found some for $14, but they say that they're for blower motor, which I'm not sure if that's another word for the Mass Airflow Sensor or if it's a compat. relay!

Thanx in advance!
~Derek

(Sorry for the long post!)

 

Locate the ALDL connector under the LH dash, remove the cover (if installed) insert a bent paper clip into pins A&B (upper right), turn on the ignition and count the SES flashes.
First a "12" will be flashed three times, followed by each trouble code three times, ending with another "12" three times.
Turn off the ignition, remove the paper clip from the ALDL and install the cover.
Bring the trouble codes here.

 

Well actually, I have an OBD I code reader. I had used it on my car a few weeks back, and I didn't get anything but the normal "12" I'm not sure if your method would produce anything else, but I figure that I'd bring this up before I go try that.

 

1) I tried the paper clip.. no error codes
2) I found the relays at a local part store. They didn't help
3) I remembered that when I changed my spark plugs many many weeks back, I had fuel on them. So I ordered some Bosch fuel injectors from FiveOMotorsports on eBay. I hope they help!!

 

You could very likely have leaking injectors. They DO cause the symptoms you describe. If I were a betting man, I might even put money on it. That said, systematic troubleshooting is always preferred to dumping money and "poking and hoping". The helms manual will show you how to properly test for leaking injectors, fuel pump check valve, and leaky regulator. Also be aware that the ford injectors are larger and will flow more fuel. Fuel pressure will have to be altered, at a minimun, to make the 24 #'ers work well.

 

Black exhaust means too rich mixture. Wet plugs with gasoline tells you TOO MUCH gasoline. The first couple of years of C4's had injector problems and they were replaced under warranty. No code will be set by too rich mixture. One way to tell if your injectors are leaking is to connect a fuel pressure gauge to the shrader valve on the end of the fuel rail and turn the ignition on and then off. On every start, the fuel pump is turned on for 2 seconds and shut off and if oil pressure rises enough (engine catches and runs) an oil pressure switch turns the fuel pump back on. GM says fuel pressure must not lose more than 1 psi in an hour. If you lose fuel pressure rapidly, then you likely have leaking injectors which causes a rich fuel to air ratio and hard starting, black exhaust, stalling...........all of your symptoms. The cure is to replace the injectors.