My 88 coupe has seen very little road time this summer because of rotting weatherstripping which makes the possibility of getting caught in a south florida downpour a very wet proposition. So I took it out 2 weekends ago to drive it a bit and it ran like crap. It was hesitating, stuttering and carrying on. The check engine light was on. I turned around and parked it. I hoped it was just due to sitting for awhile so later in the week I started it up, let it sit for a good while to get warm and then took it out. It ran fine, great, problem solved it just had to be blown out.

Well on Saturday I was hoping to take it cross state. But once I got it out on the open road the hesitation and stumbling returned. Tonight I got out the trusty paper clip and pulled the codes. I got a 32 (which I've had since I owned the car - EGR issue) but also got a 22 and a 33. I know the 22 has something to do with the TPS and the 33 is MAF related. I noticed when the stumbling started I immediately saw the check engine light flip on. If anyone could offer some advice as far as what to check from easiest and most common to most difficult / worst case I would appreciate it.

I am not a mechanic by any means but can turn a wrench and follow instructions just fine. Any guidance would be much appreciated.

 

For ECM codes
http://www.c4vettes.com/index.htm
then click the indepth thumnail and then the ECM codes.

For the MAF, there are a number of threads on this topic see the answers on the thread Help! 86 L98 stalls at idle with a code 34
redvette1986 at 5:34 earlier today in this forum......

 

Yea I saw that site I guess I was hoping for some more detailed info. Thanks I will dig around some more.

 

Well, both TPS and MAF problems will definitely cause drivability problems. These two sensors are critical to the proper operation of the engine.

They both need to be checked. First clear all error codes by disconnecting the battery for at least 30 seconds. Then:

To check the TPS you need a digital volt meter. The exact procedure should be posted in the Tech Tips section on this Forum. Without going to the trouble of re-typing the entire precedure, what you need to do is check that the voltage is .54 mV (+/- .075) with the ignition key "on" but engine not running.

You also need to use your hand and slowly open the butterflies while watching the TPS voltage readings. Voltage should steadily increase as the butterflies are opened, with NO sudden jumps in voltage. Sudden voltage spikes or voltage not increasing means the TPS is bad.

The MAF: I'd first do a visual check to make sure that connector is firmly plugged in. I'd then remove the MAF and check that none of the tiny wires located between the MAF screens (4 of them) is broken.

Re-install the MAF, start the engine and, when idling, tap the bottom of the MAF with the handle of a screwdriver. If the engine stumbles, your MAF is bad.

Before heading to the parts store, try to borrow a known good MAF (either from another 'Y' body or even an 'F' body - Camaro, Trans Am, etc) and install it. If the problem goes away, your MAF is bad.

If neither of these give positive results, you can look forward to checking all the wiring.

There may be procedures for checking the MAF in the Tech tips section too.

Hope this helps.

 

Awesome info thanks a bunch Jake!

 

Just to add a note to Jake's detailed troubleshooting...
I had a problem with the weather-pack connector to the MAF on my '96. OBD-II is good for throwing detailed codes, at least...
I cleaned the pins and slightly crimped the female connectors, reconnected it and the MIL hasn't come on in two months...
Hopefully your solution is this inexpensive as well; good luck.

 

I had same problem as mvmechanic. That thing is out there in front of God and everybody. It probably takes more abuse than any other connector.