My car was kinda choking at idle in drive or reverse soon after i'd start it. I checked the tps voltage with scan tool and got a .56. I got a 175 with IAC. No codes. So I went ahead and took the valve body off and cleaned the deposits both inside and outside. I didn't remove anything from the throttle body... all i did was polish it and replacxe what looked to be a blown gasket. I put everything back together and now I idle at 1500! in park, drive and reverse are normal... but I'm throwing a code 33 and a code 36 now. Before I started it i put in fuel system cleaner through the gas tank on less than a quarter tank. The 33 reads MAF voltage is too high, the 36 reads MAF burnoff circuit problem. I have no idea what to do. Someone please.
I just went down and checked the TPS... now it reads 3.10... would this cause a code 33 and 36???????

 

Yellow,

Clear the error codes by disconnecting the ECM power for five minutes. you can do this by disconnecting the ECM fuse or the battery (its always a good excuse to clean the battery terminals).

Run the car again and see what codes are generated. If you are idling at 1,500 RPM once the engine is warmed, you need to check the TPS and throttle minimum air position adjustment.

 

A little more engine info would be useful. In a case like this I would walk through all work performed again. IAC would be one starting point. I only say this because if it was removed it could be damaged if installed incorrectly. If it is a TPI there is a plastic vacuum line under the throttle body that could be easily forgotten.As Vader pointed out clear all codes. Start engine and wait for MIL light to come on. Read codes, look for the first one. Sometimes that is a clue as they are stored in order. Did you turn the IAC control pintle? If so, there is a procedure for reset(I will look it up). I am also wondering if the cleaner concentration(low tank) was too high and the O2 sensor got contaminated. Keep us posted, and we will help. Danno, 89 rock

 

thanks for the suggestions. But it ended up being a bad TPS. Why it didn't throw code 22 instead of 33 is beyond me. Put in a new AC delco TPS and everything is just fine. The original problem I wanted to fix by cleaning the throttle body still remains. If the car is slightly warmed up... it turns over just fine... but when I put it in gear, sometimes the rpms drop really really low and then stalls when I give it gas.

 

Did you adjust TPS voltage? Does it rev normally when out of gear? Any vacuum leaks? I would check EGR and related components. If everything else seems OK EGR would be a good starting point. EGR problems manifest themselves at idle, or on deceleration (stalls on dec.) and are fairly easy to fix. If all things are back to square one then I would take a look there. Keep me posted. Danno

 

Yellow,

Did you disassemble and clean the IAC pintle rack gear? You can remove it, clean it, and lightly lubricate it with clean engine oil, then reassemble. If the IAC is sluggish, or the minimum air position is incorrectly set, you can have hesitation at throttle tip-in.

You may also want to check the fuel pressure for grins.

 

if its still throwing a 36 after your puter re-learns then as you know its your MAF. lil suggestion a GM tech gave me, when you replace your MAF replace your relays as well. there only $10 a piece so thats cheap ins.
a way you can tell if your MAF is bad is to lossen your intake hose on the front side of your MAF. get a friend to turn your car off after its been running a lil bit of time . as your friend turn the car off remove the hose and look at the MAF wires, if they are glowing then its your relays. your AF is working if the wires are glowing.

 

I haven't thrown a code since I installed the new TPS. Now... anyone know how to get rid of that squeek that sounds like it's coming from behind the speedometer soon after starting? I tried spraying some WD40 behind the face plate, but no fix.

 

You will have to pull the instrument cluster and pull out the cable. I take it that it a mechanical speedo? Clean the cable and lubricate with a good grade grease. On these models you can't pull the cable out from the bottom, it pulls out through the top side. Just replaced mine, what a B****. Sorry, not a lot of fun. Forget the WD, all it will do is make a mess and if it hit's the faceplate of speedo it will probably wash off the numbers. LOL Danno