I have a 90 GTA with the 5.7 tpi. When I put the petal to the floor the car bogs down.

I have an adjustable fuel pressure regulator and have tried everything from 42 to 50 psi and nothing seems to help. Car is mostly stock, just has an afpr, 54mm tb, K&N filter, gutted airbox and some porting to the upper intake.

This happens at lower rpm's it starts to pull pretty good at 3000 rpm or so.

My check engine light is on but I don't have anything to check the codes with atm.

I am going to change the fuel filter tomorrow and check the timing. Anything else I should possibly be looking at? o2 sensor maybe?

Thanks.

 

you just need a paperclip to jumper A and B terminals on the ALDL port.

https://www.thirdgen.org/forums/tech...er#post2246077

https://www.thirdgen.org/service-eng...ht-error-codes

The code will blink using the SES light.

Something must be serious since the compter sees a problem, sounds like ignition related or maybe a sensor IMO.

 

tps sensor.... it has three setting that it read, idle, part idle, wot, mine went bad and did the same thing, off course mine went out when i was lined up with a mustang and was a rather embarrasing moment, as soon as my car shifted to second, it bogged and died. but at idle and part throttle it drove fine so i would look into that. some are adjustable mine isnt. but i think its like 50 - 60 bucks not much. hope this helps

 

Thanks, i'll take a look at that.

I noticed that it only does it at low speeds. If I stand on it going under 20 it accelerates fine for about a second then it bogs for 2 or 3 seconds then it is fine again. If I am going over 20 or so and stomp on it it runs fine.

Edit: I'll try the using a paper clip to get the code

 

well in that case it may not be a tps. when mine went out, as soon as i went above part throttle the car bogged. id suggest what formula recomended and jumper your ecm to get your codes, i think there is a thread that explains how to do this. i know how its hard to explain in words without confusing you. no pun intended. thanks
kevin

 

I'm going to check the codes tomorrow. I just changed the plugs, wires, cap and rotor. I am wondering if it is possibly the ignition module, I should have checked it when I did the cap and rotor.

 

Pulled the code and it is code 41, which is:

41.Fault at cam sensor OR Cylinder select error OR Tach input error

Anyone familiar with this?

 

I have a 91 Camaro. Since yours is a 90 and also has speed density, here's what I can gather from the manual. Hope it helps:

This EXACTLY what the book says code 41 is:

CYLINDER SELECT ERROR (FAULTY OR INCORRECT MEM-CAL) 5.0L (VIN F) & 5.7l(VIN 8) "F" CARLINE (PORT)

The following is some more info, kinda skimmed over by me.

THE ECM used for the engine is also used in other cars with other engines, but the difference is the MEM-CAL. If a code 41 sets, the incorrect MEM-CAL was installed, is faulty, or installed incorrectly.

Pull the ECM out and remove the little access door. CHeck the MEM-CAL to see if it's loose or if any pins are bent. Make sure it's in correctly and seated all the way. Check the part number on the MEM-CAL and see if it's the right one. If so, then it probably went bad and you need a new one. It is also possible the ECM is bad, but it shouldn't be replaced until the MEM-CAL is properly checked and replaced.


Then, it has a small flow chart outlining the diagnostic procedures:

-Igniton off, clear codes (disconnect your battery for a few min)
-Start engine and run for 1 minute or until SES light comes on.
-Pull code from ecm. Does code 41 set?
-YES-faulty connections or wrong mem-cal, or it's bad.
-NO-code 41 is intermittent. review above diagnostic methods.

Hope that helps. I tried to make it clear, lol

Kevin

 

Hey thanks for the reply.

I actually just fixed it. The car had a custom memcal in it, I replaced it with the original memcal and the problem is fixed.