My car is currently gettina bout 10 mpg. Not that im too concerned with gas mileage, but this is rediculous. I just changed the fuel filter, and adjusted all sensors. Im not too familiar with these cars, could someone please let me know the possible causes of thi sproblem? i am pretty much clueless. also, i dont know if it matter much, but i dont have a cat. i dont thin that would cause this problem, but who knows. please let me know what i sohuld do. Also, when braking, the car seems to shake back and forth a bit, not like hot spots on the rotors or anything(it actually doesnt feel like a brake problem at all), could this have something to do with my engine or transmission? Ive never felt anything like it.
shawn,
I saw you other post about your car shutting off and basically running bad. With your current statement about 10mpg, I would also agree you are running insanely rich. We need a little history on the car. Why was the person selling it..did he say? It sounded to me like it was mostly stock, but it's pretty hard to get a stock GN to run *that rich* without the previous owner playing with things incorrectly.
Do you have a scantool? This is paramout to solving your problem. A lot of time & money will be wasted without one. You can get one for less than $300, and believe me - it will pay for itself.
Do you have a fuel pressure gauge?
Could you take pictures of your engine for us to look at and see how stock it may be if you are unsure? Take close pictures of your driver's side throttle body/valvecover area - this will point out if your injectors have been upgraded and if you have an adjustable fuel pressure regulator. If you do have an adj. fuel pressure regulator - you need a fuel pressure gauge to make sure you are getting the proper pressure for your injectors.
Lastly, either stuck open injectors or the chip is probably the culprit. Feel each injector with your finger when the car is runing and try detecting pulsing or an on/off operation of the injectors. This may verify if you have an injector or more stuck open.
Try to get digital pics if you can - you can email them to me directly at mailto:gn@wideopenwest.com if you like. Something is definitely wrong with your car - there are a lot of possibilities (scantool, scantool, scantool!), but we may be able to help nail it down without one.
i will get pcitures within 24 hours. i scanned the ecm manually(as per instructions on this website) and code 22 came up-tps circiut low. I adjusted the tps again to the correct setting and the problem still exists, not as bad, but still there. anyway ill get the pictures up soon
Did you get the TPS wet? What is the idle voltage set at. Does the voltage increase steady with no black out as the throttle is increased?
3 questions:
1. How can you tell if your Adj Fuel Pressure regulator has gone bad? I'm trying to chase down a gremlin....(not the car)....
I have been using a fuel guage mounted on the rail. I know it's not accurate, so I decided to put a handheld guage on that I bought from one of our vendors.
2. The brand name is Westward. Are these accurate?
I was showing 38 lbs with disconnected vaccuum. So I upped it to 45 (using a Thrasher).
I also had made an adjustment on the actuator to back off the boost a little. Went out on a test drive and I started getting a massive boost spike. As soon as I hit 15 lbs, the car would immediately jump up to 30. I thought maybe I had some loose hose or something. I've checked every vaccuum line and don't see any leaks.
Despite the massive spike, I was not seeing much KR. About 1 to 2. The car sputters like crazy as it hits 15 lbs and spikes up to the stratosphere. However, I'm not seeing much KR. Only 1-2 at most. My O2's are in the 825 to 850 range which is probably pretty rich.
I thought maybe the fuel pressure guage is not accurate. So I turned it back down to 38. I still get 825 to 850, very little KR and big time sputtering.
3. Is it possible to hose up the actuator by taking the arm off and on over the years? The car has 42K on it.
I'm not getting any error codes, very little knock, all of my hoses are on tight, I couldn't find any cracked ones, and raising and lowering the fuel pressure does not seem to effect my O2's. I do admit that I'm not getting my readings in 3rd gear though.
After all that, does anyone have a suggestion of where to look next?
Thanks
Craig Martin
87GN