Hey! I have a 88 ta 305 tpi auto. I live in FL verry HOT. OK in the morning I can start the car and go anywere without the check eng. light coming on. But in the HOT FL afternoon I can start the car and go 1/2 mile down the road and BAM that #$%&# light comes on and the car wont get out of its own way. I have to take off verry slow or it will just start to cut out but it wont stall. It sends out a code 33. I changed the maf, maf power and burnoff relay still the same thing. HELP!!!!!!
THANKS!

 

JR Bird,

You've basically eliminated the MAF and MAF relays. The ECM was trying to tell you via the Code '33' that there was too much air being metered by the MAF sensor to be able to run the engine at the reported RPM and throttle opening.

The TPS is very important in the equation used by the ECM to calculate the expected air flow. The engine RPM signal is also very important. If the TPS voltage is set too low, the ECM will presume the throttle is open less than it truly is, and tend to set the code. The TPS voltage should be
0.47-0.60 VDC at the idle position, with 0.54VDC being the generally accepted standard. You might try to adjust the TPS higher to compensate, but still stay within the specified range. This should tip the ECM toward the correct calculation range.

Of course, this will only work if the minimum throttle position is correctly set. If someone has attempted to adjust the curb idle by moving the throttle position, the ECM may be completely confused and accept a lower TPS voltage than should be reported.

As mentioned earlier, the engine RPM signal is important to this ECM calculation as well. Make sure the distributor connections are intact. The ECM derives its RPM signal from the HEI amplifier/switch module in the base of the distributor. If some of the reference pulses are missing, the ECM will presume a lower than actual engine RPM, and expect lower intake air flow as a result. The result of either cause could be a '33'.

Good luck with this one.

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Later,
Vader
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"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

Check for leaks around the MAF box and air box and rubber duct that hooks to throttle body. You say you changed the MAF, and relays, assuming you mean new parts. Check the TPS voltage and IAC operation (clean).

Also possibly distributor pickup coil.

Since it runs good in the morning and not in the afternoon there is a possibility your fuel injectors are leaking down. When you start up in the morning they are a bit more clear from evaporation but under operation after the car shuts off they may be loading up.

 

Going to try this out tomarrow and see if I can get it. First thing is check the tps at the a+b wires. next I will check the wires in and around the dist. wish me luck!!

 

hey I tried everything and looked at everything. can it be the ecm?? I did see that the wires going into the coil looked all bent and crushed would this cause this?? if so can i get a new plug for the coil??

 

Hey jr,

I feel your pain! I'm a little South of you and I'm having pretty much the same problem. Not sure if location has anything to do with it or not, maybe humidity, but I doubt it.

The only differences between us are: 1. Occasionaly mine will do it in the morning and 2. When it does do this, it will accelerate and run somewhat normaly but when I let off the gas, RPMs drop quickly to idle range, but it wont idle, usually stalls when I stop. I let it sit for about a minute, then it's fine for a few days.

You haven't mentioned your mods, if any. I have a pretty big cam which I'm told will contribute to this problem.

Also, have you checked for vacuum leaks? Didn't help me but maybe it will you.

God help us both!

Ken