92 2.0 n/t backfiring

[SLIDER121]

I have a 92 non turbo auto with no upgrades. I have checked the timing marks and it all looks good, but still backfires out of the air box and exhaust under a load only, it won't go over 2000 rpm under that load. I have replaced the tps and the ais for idle issues which i will contribute to a bad fiav. The car had set for 5 years before I got it. I am thinking computer now. Any help would be greatly appreciated. Thanks

 

[DSM1G90]

NT 1.8, or 2.0?

If that thing sat for 5 yrs, was their fuel in the tank all this time?

If so, get that crud outta there since it's gone to varnish (prob why you're backfiring due to exhaust valves sticking some), flush out the system, and change the fuel filter.

Some techs take off the valve cover and spray down the valve train with WD-40, then roll the motor over a few times to get the WD down the valve stems, then let it sit over night.

Amazing what WD-40 does for sticky valves, for I've been there as well - soaked down a valve train to free up sticky valves.

-DSM

 

[SLIDER121]

Sorry it is a 2.0. Yea the gas was bad , dropped the tank cleaned it, changed the fuel pump(stock), changed the fuel filter twice and replaced the filters in the injectors. I did put 2 cans of berryman b12 in the tank and it helped.

 

[SLIDER121]

Ok, I'm frustrated. When it is in park and do a wot it sounds like it is taking a big gulp of air and seems to bog, just for the heck of it I tried to drive it and it has small backfires in the exhaust and no balls. I thought maybe the torqe convertor was staying in lockup, but don't think that is the case. The timing seems to be correct. Any suggestions. Thanks.

 

[DSM1G90]

Done anything with the ECU?

 

[SLIDER121]

I opened the module looked good. I'm going to get the drb3 from work to check everything but I have to find the correct card. I was wandering if this could be a cam sensor issue?

 

[DSM1G90]

I've replaced my CAS due to similar (course, I'm a 1990 CAS making yours a different setup ..), but wondering even though the ECU can look good, but some internal components have gotten bad .. like sensor drivers.... and those have to be tested out on a tech's workbench...

 

[Pauly D]

I whould check to see if your catalytic converter is good. Sitiing for 5 years those things give out if u let your car sit a month let alone 5 years. Well at least to my knowledge they do.

 

[atownturbo]

Any vacuum leaks?

 

[SLIDER121]

I want to thank all of you for taking the time to help me. It doesn't have a cat and no vacuum leaks that I have been able to find. If the fiav is working incorrectly could that be part of or the problem?

 

[DSM1G90]

If the fiav is working incorrectly

yeppers, it's a big link in the idle chain ... On a side note: how's your cooling system - system totally flushed, including the radiator with new coolant at a 50/50 mix?

 

[SLIDER121]

the cooling system is ok, it could use a good flushing ,but it doesn't overheat and since I replaced the fan sensor the fans kick on like they are suppose to.

 

[SLIDER121]

ok, I hooked up a drb3 to the car checked sensors and then the reader locked up. I am thinking the computer is bad.

 

[jrohner]

If the fiav is working incorrectly could that be part of or the problem?

That's for idle, it wouldn't effect how the car drives whether it's working, stuck open, or stuck shut.

 

[SLIDER121]

Ok, I replaced the ecm and the car is doing better. I'm gonna do a fuel presseure test to make sure I have the correct pressure, it still cuts out with the brakes applied in gear at 15-1800 rpm or in gear without brakes applied at 4000 rpm.

 

[SLIDER121]

Fuel pressure was fine at 47 lbs. Still have no power on acceleration.

 

[SLIDER121]

Alright guys, looks like I found the problem. I did a compression test and found to have a dead #1 hole, put air to it and air was coming from the throttlebody which is intake valves or dropped the seats. I will have to pull the head off to find out. Get back to you with details.

 

[SLIDER121]

Ok, I have 2 bent intake valves. I'll replace those check the head and hopefully be on the road this weekend.

 

[SLIDER121]

WOW... replaced the valves it's amazing at how much better it runs when it has all cylinders.

 

[92AWDTalonTSI]

Wow. It's not common to see anyone come on here, ask a few questions and tackle the issue.

Most of the time people either give up, take it to a shop or keep asking questions to run around the problems they don't want to bother with.

Good job.

No small feat you had there.

 

[SLIDER121]

Thank you for the kind words.

 

[Trav83]

Wow. It's not common to see anyone come on here, ask a few questions and tackle the issue.

Most of the time people either give up, take it to a shop or keep asking questions to run around the problems they don't want to bother with.

Good job.

No small feat you had there.

So True


Glad you figured it out, well done