I have an 87 IROC 305 I just bought and it's got the awesome SES light. Pulled code 34 from it, low flow, signal high for MAF. I searched these forums and found a lot of useful places to start.

First I tried clearing it, to see if it was a lingering code, but it came back.


Second I tried checking the fuses and relays. Fuse on the passenger side fender looks fine and the relays, well I just replaced them as well as the fuel pump relay since it was in bad shape.

Third, took the MAF sensor out and it looks fine and pretty new. The sensor looks like it had been replaced, since I believe the original has the fin heatsinks in it, and the PCB inside looked spanking new. Took the snorkel off and I feel a suction into the MAF, so as the code says I suppose the air flow is fine.

What do I look at next? I don't think the car is running rough at all, seems to drive just fine. If it is in limp mode I would be surprised, but I do not know since it has been on ever since I purchased the vehicle.

 

If you let the car go into closed loop before you drive it, will the ses light still come on? Mine did the same thing even with new relays and maf, tried a known good maf with the same results. I found if I let the car go into closed loop first before I drive it, there are no problems. With the stock motor and chip, the car would lose a little power and throttle response when the light came on, but with the new motor and custom chip it goes nuts and you can't drive it. I was thinking of adding a heated O2 sensor so the car will go into closed loop quickly. I know it's not the right way of fixing it, but it should work.

 

on the maf sensor is it a hot wire or hot film type the wire one looks like the inside of a light bulb when u look through the maf if it is that one try a flim type and see if you still get it i had it and was using a flim type went to hot wire and never came back

 

I've tried both types on mine, same problem. Both sensors work fine in my other '86.

 

My MAF has a circuit board going through the middle of it...

 

Code 34 is very seldom the MAF sensor itself failing. A misadjusted or malfunctioning TPS will cause a code 34, also another culprit believe it or not is leaking injectors. Test your TPS voltage first and let us know what the readings are. Also put a fuel presure gauge on the test port on the rail and let us know how fast your fuel pressure bleeds down.

I fought a code 34 for a year before I figured it out. Turned out mine was caused by the injectors leaking.

Do some testing and post the results and we will see if we can help you track it down.

 

Thanks for the info. I'll test the TPS this week/next weekend and post the results. I would need to get a fuel pressure gauge though, so I'll do the TPS first.

 

Any thoughts for me (not trying to hijack)? My tps is dead on, my injectors are new and I only have the problem if I start driving the car before it goes into closed loop. Thinking back, mine may set a code 33? It is a maf code, I do remember that.

 

Well I finally had some time to go out and look at this. The tech article for adjusting this didn't seem to have enough detail for me, being new to all of this. anyways, i found this page by searching this forum:

http://www.sethirdgen.org/tps.htm

I used the second method with the paperclip. I got a 0 reading on my DMM, maybe I am using it incorrectly or not getting a contact with the wire. Anyways, under further inspection I noticed that my TPS sensor was missing the bottom adjustment screw. I rotated the TPS to find out that the screw had been snapped inside the throttle body (damn previous owners). Anyways, I am pretty sure that my Camaro was not an IROC to begin with or was a 4bbl IROC converted to TPI at a later date (hoping for the second). If anyone could go into more detail about checking the TPS voltage a better way, I'm all ears

I also found 2 extra plugs not plugged into anything by the TPS sensor. A green and a white plug that seem to be in the same wiring loom. It goes into a big cluster of other looms and wires that runs along the manifold. Not sure where those go but who knows if it has anything to do with my problem.

 

had same code on my 87. was the TPS causing it. bought a new one set it and no problems.

 

Thanks for the info. Maybe I'll just buy a new TPS sensor and hopefully be able to get the screw out of the tb. I would hate to have to spend much more on the setup, I just want the code to go away so I can get plates. I don't want to put too much money into it because I will be putting in a 383 block with carb into the IROC sometime in the next year or so and selling the 305 w/ tpi.