Well I have been having some serious issues with my car. About a week ago my alternator went out so I replaced that. Then I decided to fix my rear end mount, replace my transmission and clutch. The car ran great.... for about two hours. All of a sudden my car just starts bogging and backfiring. Poor idle and sounds like crap.

After further inspection, we found that the car runs great after 3800 rpms. So we figured that the injectors were stuck open for some odd reason. We replaced the injectors, all 4, and no change. After that didn't work we then decided to replace the cpu, and it still runs the same. So we have replaced the alternator, injectors, variable resistor, cpu, spark plugs and wires. Now we are going to try the replacing the air sensor, crank angle, TB, and the coil packs.

If anyone has any input with this problem it would be greatly appreciated. We are very confused with this, and have never ran into such a problem before.

 

maybe you could post year and model???

 

oh sorry...88 n/a.

 

What rpm does it start bogging at?

 

It bogs right away. It idles fine when I first start it, but when its under a load it starts jerking and bogging. Once you clear the fuel out and keep it above 3800rpms it runs, not normal but enough to drive it.

 

Did you by any change the angle of the AFM?

 

My car was bogging and Jerking terribly after about 40 seconds when I put on a new TB. Just needed to adjust the TPS. pretty simplet ook maybe 10 minutes to fine tune it.

Mountign the TPS was another story though....

 

Sounds to me like the TPS isn't functioning correctly, but possibly sounds like compression isn't good.
-justin

 

Thanks, I'll give the tps a try. If that doesn't work, I'll try a different tps then go from there...As for compression, the car seems to run fine (when it was working)but I will test it out tonight. I'm leaning towards the tps now because before all this I had a bouncing idle, but it only was for a minute durind a cold start.

 

I am the other person working on his car.

The compression in the engine is fine. as Zero stated the car runs fine after 3800.

Zero also has failed to mention that every once in a while it iwill run fine all together. its the wierdest thing, it will go from running like crap, to running fine, to running like crap at will. THis is why i thought it was the computer. but after replacing the computer, we found this is not the cause.

the car acts like it is extreamly rich from idle to 3800 RPMs (when its doing it's thing) (this is what made us think it was the injectors sticking open untill re replaced them and found out it does the same thing.)

Zero also failed to mentioned that the timming is set correctly.

tonight we plan on replacing the AFM, TPS/TB, DIS/CAS, and the coil packs.

after that, i really dont know what else to try. anyone else had this problem?

 

did replacing the AFM solve this...mine does the same thing and the AFM is the culprit...ckeckt he FSM for the OHM and test the terminals....even if you see that the terminals hold the specified resistance per the FSM, wait a while to see if it maintains it...if it does not then you will knwo why the car runs fince sometimes and liek crap at other times

 

replacing mine will not help my typing will it?

 

It's gotta be the airflow meter. Try swapping with a friend who has a 7 and see if that works.

 

not trying to steal your thread or anything but since this is somewhat related. How much does a new s5 n/a TPS cost? thanks.

 

we replaced the AFM a few days ago. this seems to be the problem as it has not done it since!

 

my car is doing the same thing, but it seems as if one of my injectors are leaking.

 

The TPS may have a perfect idle value, but it is worn & has a dead spot further up in the sweep, you will get intermittant fuel cuts.

See the linked video > short video