I'm working on a 1991 Camaro RS 3.1L,, I got the car as it had been sitting for 10 years half outside half inside.

Now let me start off by saying the last 3 digits of the vin# are 666! and I'm starting to believe this car is cursed.

I;m mostly a ford person but decided to try the GM side out.

Here's what the car needed and has been done so far.

The gas tank was empty and full of rust so it was flushed and the pickup/sender and pump were replaced and fresh gas put in.

Fuel Filter was replaced
Plugs/Wires/Cap Rotor were all replaced
Timing set at 10* with Wire disconnected
All injectors were replaced with Bosch units (goodbye delphi injectors)
TPS replaced
Idle motor replaced
MAP sensor replaced
Ignition Module Replaced

it was hard to believe all of this stuff was bad but I think the weather or the fact it was sitting for so long deteriated all of it.

We finally are getting to the point where the car will start (but not good) it takes like 5 or 6 attemps and have to fiddle with gas pedal to make it run.

It idles great! smooth with no misses.

Now here's the major prob,, it has NO POWER I mean it will bug as soon as you tap the gas,, it will rev in neutral if you gradually increase the pedal but hit it fast it will bog badly and then rev.

In drive the car will not go above 5-10mph,,, it bogs terribly! and pops out the exhaust. almost wont make it up driveway

there was a check engine light related to the knock sensor circuit,, but I believe that the wire going to it was loose as the connector is cracked and when I tugged on it it came right off,, no light since making sure it was on tight.

I'm about to install a new 02 sensor in it just for the hell of it (orig 72K miles) but the problem I have with that is it takes roughly 1 minute for 02 sensor to run and warm up before car goes into closed loop so the problem would be there when car is warm not cold,, but the problem is there in both cold and hot situations.

I would like to install a FP gauge and watch the FP but it almost impossible because of the design of the intake to install a gauge and bolt the intake back down. why no pressure port is a mystery???

I've done compression test and its within 2% of 180psi accross the board so I will rule out mechanical.

I'm down to Pressure regulator, ECM or 02 Sensor and other things I should know about these cars?

Thanks for listening,
Brad M

 

Check the catalitic converter and for a crossed plug wire

 

ya. i am not trying to be a jerk or infer anything but i put the wires on my friends ford on wrong b/c i was thinking chevy. So i would check that first. obvious stuff first. then check the plugs to see if it's rich, lean, detonating etc.

if all fails get a LS2 or 383. lol!

 

Cats seems fine,, no backpressure you can almost tell a plugged cat as it will quiet the exhaust extremely and this baby flows (no catback installed)

Orig we changed plugs after it was running and the ones in there seemed like it was running rich (black) new plugs are starting to look same.

Firing order is correct checked 3 times,, no crossfire as everything is seperated. like I stated it idles great.

 

check the coil and distrib mod also for vaccum leaks you can check fp at the filter

 

and no black smoke from burning rich i assume (at idle)?

 

no smoke at all.

never even thought about putting FP gauge at the filter (bangin head)

I'm gonna pull apart fuel pressure reg friday,, I assume they sell rebuild kits?

 

i wouldn't be surprised if they sold you the wrong fuel pump.
just by looking to them, you can't tell the difference.
most TBI pumps will only put out about 16~18 PSI, some can hit 25 PSI.
you need around 40+ PSI.

it has a test port, but its not really easy to get to.
the attached pic should help you fine it.

 

I seriously must have been blind not to see that port when I replaced the injectors..

I dunno what it is about this car but makes me feel like its my first time working on ****.

 

you probably have a TBI fuel pump .... I got one by mistake in a TPI car and it did what yours is doing. Mine would pop through the intake, idle fine and bog the second it was under any type of a load but would rev up sorta freely in nuetral.

 

and once again the TBI is blamed for the problems, this time in a V6!

 

hey good thing about having a TBI car is you can't get the wrong fuel pump hahaha mine runs nice with a TPI pump.

 

so does the car run?

 

My '92 RS is doing the same things. It is a 305 TBI. MAP sensor checked out, IAC valve/motor change made no diffrence, TPS checks ok(0.62v). Confudlled as to why I got a code 33 once for Vac low / MAP volt High and a code 54? Got these codes three times back to back and motor barely stays running at Wide Open Throttle. I've been stumped for two months with this problem and the threat of having to rebuild my tranny in my van is putting more and more pressure on me to figure this out. What about EGR control or the AIR system? Steady Vacum when tested with finger covering hole partially no guage to test it (I'm know as a poorfessional).

 

I have had the beginning problems more than once. Only two things happenned, over and over.

1. Plugged cat or muffler. Mine finally got to the point where it would only run at full throttle.. You can just disconnect the exhaust to test this theory...

2. More than once I have had the ignition coil die. The insulation breaks down and half the spark shorts through to the mount bracket. You need to run the engine in the dark and see the sparks fly!!

 

The coil is brand new but I have also thought of the clogged exaust theory. HMMMMMMM.......... I'll try that to mar row, Don't know why I haven't before. Is it possible that I may have damged my O2 sensor by spraying carb cleaner down the throttle body or is this just coinkidinkal?

 

Nah, the only thing I have seen actually damage an O2 sensor is acetylene from a torch... and old age!

Just drop the pipe in front of the cat and then see what you have

 

Well low and behold I checked the FP and it was 15psi!! for sure they sold me a TBI pump.

changed it out with one I had in garage and now its 40psi steady..


BUT!! now the car starts great! and idles great.

we took it out for a test drive and it ran perfect around the block great power except it started up with the same problems again.. almost like it was starving for fuel and bogging terribly!! if I even attemped to touch the gas it would die. but it would return to idle and run great??

got it back in the garage and checked the FP again and it was steady at 38PSI and jumped to 40-42 while revving.

Changed the coolant and checked over everything.. pulled it back out and hit the gas and it took off like a bat outa hell for like 4 seconds then it started to bog all over again and proceded to just get worse to the point where I couldnt touch the gas?

So now I'm left with:
MAP (went back to the original)
TEMP sensor (Air or Water)
02 Sensor?


EDIT: yes I did reset ECM