All stock except for a test pipe back exhaust 45k mile GN. After I pulled the stock setup, engine killing Caspers chip out of it and put the stock chip back in it has run good for the first 50 miles I've owned it, until tonight when I went out for a ride along with a WE4 buddy and for the first time my car was skipping and popping under any kind of throttle. When I would shut it off and restart it, it would run fine thru a gear change sequence and then start laying down again, and hesitating and popping. The more throttle I give it the worse it runs. Fuel filter?
Just like that, running like a p.o.s.
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scot w.
GNSperformance.com
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Fuel filter, waste gate hoses, plug wires. Check all the basics. I have had a couple cars driven to me from long distance to find the waste gate hose blown off the plastic Tee.
The car ran fine when I parked it 2 days ago. I pulled it out and washed it last night and then went for a ride. I looked to see if anything got wet, then I checked all the grounds both straps and fuseables and at the battery. I basically checked all the old school tricks I could check by hand and eye. No service engine light. The part that I don't get is that it will run fine briefly if I shut it off and restart it. As I get down the road it starts acting up again. I can pull over shut it off and restart it and it will take off fine, even full throttle right through the gears. Then I'll let off and drive normal and as soon as I try to give it some pedal again it hesitates and pops. The engine being hot or cold makes no difference.
All cars are weird,these included.
I was driving my car pretty hard one night and it never missed a beat,like always ran like a top. Came home parked it in the garage go out the next morning and wouldn't start, checked all the little stuff; fuses,power wire for the ecm,fuel pump,hoses,electrical connections,etc. turned out to be the ignition module had went bad.
just sitting over night.:frown: John :smile:
First of all thank you, I appreciate the responses. I went into the garage this morning and I could smell fuel but nothing is wet, which makes me think spark issue. I pulled it out to get a daylight look at things and just moving around the driveway it is now running rough and stumbling. Its probably my imagination but the fuel pump also seems noisier. As soon as I get another 1/2 hour free of my kids I'll do a plug check. I know its not OBD2 but what can a good scan tool diagnose or rule out on these?
Turbo6Smackdown
Well-Known Member
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- Dec 31, 2005
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- 6,110
Don't give up man. ALL used car purchases can do this. It's not the car, it's not the prior owner. It's a used car. Trust me, the people here can get this car sorted out for you, I promise you. Just stay with it.
Give me some history. What gauges do you have. Any scan tools? Was the car raced in it's history? (most likely)
Where has it grown up at? The south, or rust belt. Have you done any spring cleaning to it yet?
Give me some history. What gauges do you have. Any scan tools? Was the car raced in it's history? (most likely)
Where has it grown up at? The south, or rust belt. Have you done any spring cleaning to it yet?
turbo39151
anycoloraslongasitsblack
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- Nov 7, 2002
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- 4,460
Sounds like a MAF. Ask your WE4 buddy to let you swap his onto your car and see if it changes anything. No scan tool needed for that one. BTW, do yourself a favor and buy a scanmaster at least...
The car is mostly stock. Stock airbox/filter, stock chip, down pipe, no cat, hooker cat back, all fluids clean, open air breather, clean intake tube and intercooler (not oily) original coil pack/wires, no signs of ever having gauges or aftermarket intake, no stress cracks, has auxilary tranny cooler, no rubber in wheel wells. Carfax and Autocheck have it spending most of it's 45k mile life in Ohio. Just about everything under the hood is clean and in factory locations. It did have a Caspers chip in it when I first got it, the stock chip was in the glove box. I pulled the Caspers one and put the stock one in. The car idled and ran smoother with the stock chip. Compared to stock the Caspers one had some knock and a few hundred rpms more before shifting. I'm gonna try to put a SNAP-ON scan tool on it this afternoon. No check engine lights, and 10-4 on the Scanmaster.
turbo39151
anycoloraslongasitsblack
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Might want to try a TT chip TurboTweak Home
Does the caspers chip have anything marked on it or any numbers to identify it being for stock injectors?
It has some ballpoint pen written #s, I emailed Caspers to see if I could get info on the chip. That was over a week ago....
Anyways, I haven't scanned it yet but my wife did give me a break from my 4 and 6 year old boys and I'm positive it's fuel pump and or strainer sock related. When I first start the car it runs smooth and the fuel pump hums away normally. As soon as I move the car around, close a door or (most importantly) bang on the tank the pump changes tone, gets louder, and the whole tank starts vibrating. Then the car starts running lousy again. Shut it off and restart it and it starts out pumping normal till something upsets it again. So I'm sure it's the pump but, I still plan on scanning it and checking fuel pressure from the stock Bosch unit though.
Turbo6Smackdown
Well-Known Member
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Alright then. Here's what ya do. It's gonna suck, but it's what I would do.
Yank the injectors, have them cleaned and flowed from witchhunter, or somewhere like that. Verify their flow rate as well.
Check the coil pack, plugs and wires. Make sure they're doing what they're supposed to do. Get a new fuel pump and hotwire kit from full throttle speed. Get a new airfilter as well. Standard issue from autozone will work fine. Ensure the maf is doing what it's supposed to be doing, and triple check your maf hose for ANY leaks. Take it off, put it in the dark, and use a flashlight, to see if there's any pinholes in 'er.
After that is done, reassemble everything, and have turbotweak cut ya a new chip. A standard issue 92 chip will do you just fine.
Empty the gas tank as completely as you can, throw some good 93 in er, and then change the fuel filter. After that's done, install a oil pressure gauge, a boost gauge, and a scanmaster. This is VERY important.
Tell me what ya come up with. I want a 3 page report on my desk my wednesday morning.
I'm pretty confident this will fix your problems.
Yank the injectors, have them cleaned and flowed from witchhunter, or somewhere like that. Verify their flow rate as well.
Check the coil pack, plugs and wires. Make sure they're doing what they're supposed to do. Get a new fuel pump and hotwire kit from full throttle speed. Get a new airfilter as well. Standard issue from autozone will work fine. Ensure the maf is doing what it's supposed to be doing, and triple check your maf hose for ANY leaks. Take it off, put it in the dark, and use a flashlight, to see if there's any pinholes in 'er.
After that is done, reassemble everything, and have turbotweak cut ya a new chip. A standard issue 92 chip will do you just fine.
Empty the gas tank as completely as you can, throw some good 93 in er, and then change the fuel filter. After that's done, install a oil pressure gauge, a boost gauge, and a scanmaster. This is VERY important.
Tell me what ya come up with. I want a 3 page report on my desk my wednesday morning.
I'm pretty confident this will fix your problems.
Thanks for the laundry list. I checked the intake hose for holes when I first got the car but, not the flashlight trick. I will do that. For now I will also be ordering pump/hot wire and fuel filter. My buddy came over this moring and we put his pressure gauge on. At it's best with the car first started and the pump running "normal" I was only getting 28lbs at idle. As soon as I smacked the tank and the pump started growling and vibrating the pressure dropped to 24 psi and the car started stumbling and it would stay that way till I shut the car off. When I shut it off the gauge quickly dropped to 0 and I assume it should hold pressure?.
turbo39151
anycoloraslongasitsblack
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Yes it should hold pressure.
Turbo6Smackdown
Well-Known Member
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Yes sirree. Oh yea, one more thing you're going to need. Adjustable fuel pressure regulator, and fuel pressure gauge 
