AWD Laser pulls hard first and second, hesitates in third..?

[Burntrubber87]

My car has been sitting for awhile, I took it out for a ride ('92 awd laser) and it was running strong in first and second but third boosted good until about 4-5.5K RPM and it would hesitate/sometimes cut out/backfire etc, but then sometimes the car runs fine in third gear and strong into fourth..its running 16 psi stock motor with cone filter and a broken dp. going to fix the exhaust and hopefully get the boost down. Do you guys think this could have been fuel cut at 16-17 psi? or maybe the car has bad gas..it has fresh plugs and newish wires..i'm not sure.

 

[1992awdlaser]

My first thought was fuel cut. Does it accelerate and then stop all of a sudden? Or does it just not pull as hard as first and second gear?

 

[xdxoxuxgx]

If it feels like its hitting a brick wall then its fuel cut

 

[Burntrubber87]

It does it differently sometimes. Once it backfired and cut out for a second. Sometimes it will hesitate and buck hard but i usually get out of it once it starts hesitating you know.

 

[1992awdlaser]

Check for boost leaks. That probably not the problem but it can't hurt.

 

[Burntrubber87]

Check for boost leaks. That probably not the problem but it can't hurt.

Yeah i was definently going to do that..how do you check for leaks past the throttle body? I am making about 20 lbs of vacuum at idle and around 25-30 in decel in gear..that should mean that everything past the TB is in good shape, right?

 

[xdxoxuxgx]

Those are really good vacuum numbers, your boost leak test should pass with flying colors

 

[Burntrubber87]

What i'm going to do is run this gas out of the car, put in some fresh 93..and maybe new plugs with the exhaust fixed and see where i'm standing with the high boost/ third gear problems. and do a boost leak test..if not that then i'm not to sure what to do.

 

[welfle18]

I would check your plug gaps. I had a hesitation problem when I checked my plugs they were pretty far off like a .045 gap fixed that and voilà the problem was fixed. Something that I would check out.

 

[B-Man]

My 3000gt did something similar when the plug wires went bad. I'd check plugs too like what welfle18 said.

 

[My1GLaser]

My car was doing this at 16 psi on a 14b. Long story short...it was a fuel supply issue. My inj duty cycle was fine, but I was not getting enough fuel according to my WB, O2 sens voltage & DSMLink. My lb/min is higher in 3rd then 2nd or 1st (of course), so I was running lean at about 5000 rpm in 3rd (not 1st or 2nd).

I would say clogged fuel filter, clogged injectors, clogged fuel pump "sock", bad FPR or pump...lastly it could be a rusted fuel tank. I don't know how prone our cars are to this, but I had a 91 hyundai excel that sat for 16 months and the tank rusted. The longer I drove the more rust packed up into the filter. If I let it sit the rust would settle back down and I could drive it again. It took a while before I saw the pattern.

 

[My98slvrGSX]

is it when your wide open? or like at half throttle?

 

[Burntrubber87]

I'm gonna go check the gap on the plugs now. And it was doing it at like 3/4-WOT. also does anyone know why my gauge cluster lights and rear running lights wouldn't be turning on..does anyone have the stock underdash fuse box diagram..or know where to find it online..or just tell me which ones to check.

 

[My98slvrGSX]

i had my brake and rear running light module go bad. and my brake or running lights wouldnt work. its located behind the stero. check that maybe?