It seems to me from reading many many posts related to MAFSs that they are very erradic and random. Some people can can remove screens and they still run fine. Some people remove screens and they get codes. Some people can run this or that aftermarket brand and be ok while others put them on and get codes for no apparent reason. What the hell? This doesn't seem logical to me at all and I myself am dealing with a very frustrating problem with a code 33 and am wondering what is going on!?

 

There can be quite a few reasons why the ECM is triggering a code 33. In my experience, it is the most common trouble code there is for our cars...

If you replaced the MAF sensor itself, as well as all of the relay's... did you at least run through the wiring harness, and make sure that none of the wires that are associated with the Mass Air Flow are being pinched, or are cut?

Aside from the code 33, how does the car run? When she warms up, what is her RPM at idle? Does she run rough? Is she shifting horrible? Is she in 'Limp Home Mode'?

 

Have you checked the rubber duct from the MAF sensor to the throttle body to see if it fits properly or has any small holes or tears in it that would cause an excess of air to the throttle body?

The Trickster!!!!!!!!!!!!!!

 

The car runs well.. sometimes the car will idle fine and other times it will fluctuate up and down a bit. I have checked the ducting to the trottlebody and it looks good. I will usually get the code 33 after driving for a minute or two... Then it runs almost the same but feels like it wants to die a little at low rpms...

 

are you using a K&N air filter?

 

When you say fluctuate, do you mean you're 'surging' while you drive? When you let go of the gas (in gear), does it feel like (at low RPM's) the gas pedal is being pressed, then depressed. then pressed etc..., that type of surge?

Trust me, don't even bother trying to set the IAC or TPS.....with that error code, you'll never get it running 'right' until the code is removed. I had the exact same problem, and it turned out it was my ECM (this is why I swapped to a Carb, cuz I had no time to deal with it).....

 

Yes I am using K&N and it only surges in park, not in drive.

 

if the K&N's are over oiled , it is possible to contaminate the MAF,....... you can clean the MAF with some electrical contact cleaner






worth a try

 

What kind of MAF are you running? Is it the original? If you're only surging in park, and not in gear, then I wouldn't worry about it.... it's prolly the slightest 'pinch' in the harness that's causing the code.

How did you re-set the ECM? Did you disconnect the battery, or did you just remove the fuse? I don't think it's the K&N Filter, cuz if the MAF were being contaminated.... it would eventually trigger a code 36 along with the 33..

 

Try this.... with the battery disconnected, remove the connector to the MAF Power Relay, and make sure the terminals are at their furthest point possible. Hold all the wires in place, then firmly push the connector back into the Power Relay. Re-connect the battery after about 10 minutes, then start the car...

Did the SES light come back on?

 

If people left them alone half the problems would not exist. First, get rid of the K&N filter. I have 4 chevy's all had them. Take a look at the throttle body after a year with a K&N. The MAF hotwire is very sensitive to any type of contaminate. If the MAF burnoff is not cleaning the hotwire you get sluggish or a totally inactive MAF. The most common problems are the relays, replace both of them before going any further. Try some contact cleaner on the plug at the MAF. Don't spray anything on the hotwire or you will be buying a new MAF in short order. Generally if you don't have a code GENTLY tap the MAF and see if the idle stumbles, same with the relays. As was mentioned a leak could be a problem anywhere in the intake area but that will generally throw an O2 code as well. Always reset the ECM and clear codes before trying to troubleshoot. After you find it go back to a stock pleated paper air filter.

 

where are these MAF relays located?

 

MY 89 has them on the driver side firewall to the right of the fuel pump relay. They are the same part number.

 

thank you, i found them and replaced reset the ECm and my code 36 is code

 

thank you, i found them and replaced reset the ECm and my code 36 is code

 

my 87 ta has a code 33 set i have replaced everything but the wires and ecm , im guessing that your car has had a engine swap at 1 point in its life like mine(305 to 350) & it has the wrong prom in it. ihave messed with this MAF system 4 2years now and every time i run through the diagnostic table i get "faulty MAF" & i have put 2 different bosh (oem)MAF's in & i still get "faulty MAF" I suggest getting the engine ID #off the front of your engine and order a hypertech chip(prom) 4 it. i have 1 on the way. im hoping this fixes the problem &if it does u get a perfomance chip 2 (id that prom mine was wrong)