What she is:

'87 IROC TPI... 305 converted to a 350

w/ stock 350 memcal, knock sensor, 24lb svo injectors, Comp XE 262H-4 Camshaft.... 416 casting heads w/ 2.02/1.60 valves... hedman headers w/ a.i.r.

Now and then I get the MAF code 33 and the engine runs like crap, and Idles even more erratic than it does now.

I've set TPS voltage, minimum air, checked vacuum lines, cleaned the IAC, run through a list of code 33 wiring and voltage checks, replaced burnoff and main maf relays.

Code popped up again today for no reason.... ran bad. came home... went through all the steps again, still had it. Played with the idle screw while running and the SES light went out and all is fine again.... But I had already set minimum air. MULTIPLE times in the strive to get the code to STAY AWAY. Code has been off for about a week and I'd done nothing to it since then except drive it.

What's going on??!?! Can the MAF sensor itself be intermittant?

I was reading some posts about the MAF and came across someone saying this :

lots of mods like cam/heads etc, maf high diag error 33 threshold under ecm constants needs to be increased.

Is that something that I need to change? could that be causing this? I don't see how my ECM can be bad because it wasn't doing this before and I'm getting proper readings of terminal C and terminal B to the ECM. I get .03v from terminal B, w/ or w/o burnoff relay and main relays disconnected. and my grounds are good.

ANYONE have somemore ideas?!

 

You can only get rid of the dreaded 33 error code by having a custom chip burned for your car.

Just for the heck of it, reset the ECM and then drive the car and when on the xway or country road where you are driving at steady speed make sure that the engine RPM is ALWAYS above 2000RPM. Select a gear which will keep the engine above 2000RPM. If you have a 5 speed, maybe run in 4th gear until higher speed is reached.

I have on automatic in my '87, I could prevent the ECM setting the 33 code if I stayed in 3rd gear as I drove around and when I got on the xway, I would not shift to OD until about 65mph because then in OD the engine speed would be above 2000RPM. Try it out.

 

Typically I stay in D until I hit a cruising 50... mostly because if I give it more than 1/2 throttle in OD it slips like crazy, not sure why. Drove around today at 60 on the xway in OD and no code. Was fine all day no code, I'll keep an eye on it though and see when it pops up. When it happened yesterday I was going 35mph in D.... just may have been below 2000 rpm.

 

holy **** im having the exact same problem.