Hi guys from heart of europe
I have camaro 1986, 2.8 multiport FI. I could start but no power and no speed if I stepp on the gas pedal.
I replace:
sparg plugs (ngk 2771)
Ignition control module (ACDelco D1943A)
pickup coil
ignition coil (UNITED MOTOR PRODUCTS C535)
Catalytic converter is ok (replaced some years ago)
.
and no change

Diagnostic say only 34-MAF (but this sensor is bad some years and car was run good)

Engine running video: I try test fuel presure and seems ok. video: (its quite loud, I remove catalytic converter)


Any idea where is problem? Thank you for reply and sorry for my english

 

Do you have access to a scan tool? And can you do a backpressure test? If youre flooring it and RPMs do not rise like they used to then something could be plugged. Also youre english is good.

 

I know you don't want to hear this , , , BUT , proper troubleshooting procedure literally demands that you repair the known faults first , before you go chasing your tail looking for a malfunction that just may well involve the code 34 !

There are various levels of MAF failure , as in perhaps when the first code 34 appeared some years ago the MAF voltage output was slightly low , enough to trigger the code but not low enough to affect the running of the engine . Now , some years later maybe the MAF has finally totally failed , no output whatsoever , and this very well could cause the issue your now experiencing .

The new MAF may well or may well not solve your problem , but like I said earlier , before blindly throwing one more random part at the car , fix what you KNOW is broken first , and then if the problem persists then take the troubleshooting from there . If a new MAF doesn't fix it , as a next step put a "noid light" on both injector banks (after checking the fuses INJ 1 and INJ 2) , to make sure all 6 of your injectors are actually spraying fuel into the engine .

PS , Before you DO replace the MAF , using this handy wiring diagram for your engine make sure you do have +12V on the light blue wire coming from the MAF relay

 

Pro: No, I have no scan tool, what you mean exactly? Is some better for my old camaro, than MIL(service engine light and plug wire between A and B pin on the diagnostic conector)? Same with "backpressure test".. but I try use google for more info

OrangeBird: I understand you, but real sittuation is: MAF was totaly dead some years ago(interupted wire on PCB - no signal to ECU ) and camaro was run in safe mode good. The problem is new.
All fuses are ok, but I try check the injectors.

Today I noticed on the back side of throttle it too much carbon with oil or fuel(carbon is not dry but greasy). Same in manifod intake - I try disassemble it and cean.
If I start engine and unplug conector from TPS sensor, RPM will increase 2x or 3x (i dont know exactly, i have no tachometr) and engine run pretty good (on this RPM)

I make video with cold start.. Is here Before star(after keys move to ON position) is heard creak sound(same if I turn off the engine).. what can it be? fuel regulator? Stepper motor is silent and sound comes out of that place somewhere.

 

It sounds like you just have a code reader. You need a scanner with an ALDL cable.
You can get one complete unit like this:
http://www.1320electronics.com/products.html
And then sync it up with your phone/tablet. Start up the car and check out your fuel trims, O2 sensor readings, etc.
Or you can get an ALDL cable from moates.net, tunerpro rt (free), and a laptop and do the same. But the first link I posted would get you started quicker.

 

Thanks, I look at it.

Is some chance that the software will be work with this scaner+reduction cable?:

scaner elm327: https://www.aliexpress.com/item/ELM3...ceBeautifyAB=0

reduction ALDL-OBD2: https://www.ebay.de/itm/Diagnosegera...QAAOSwdzla~oYP

I buy elm327 one year ago for my ford. Reduction I can buy from a neighboring country.. It will be about 2 weeks faster.

 

Problem solved. Bad throttle possition sensor.