I have a 1989 Pontiac Formula with the L98 350. Please see signature below for mods that have been done so that I can try to keep this short. I feel that my car is running rich because when I hit it off the line, it feels like it is bogging down and there is a hesitation in the throttle response. I have done all the conventional mods for bringing more air into the motor (holes in air cleaner, bigger TB,etc...) and I am wondering if the computer is adding to much fuel to the system. I also have an AFPR on the car and I would like to set it at 50psi but I have not gotten the instructions on how to set it yet. Once I get those, I will adjust AFPR to 50psi and see if that helps or hurts. 50psi because I have been watching the boards and everyone else seems to have good response from this PSI setting.

Is there any sure-fire method that will tell me if I am running to rich or not. I have a custom burned PROM from Ed Wright and it was burned with the stock fuel injectors for the car. I have not changed those and they are original items.

Any direction on this problem would be grately appreciated.

 

the only way to tell if your car is running rich is to hook it up to a code scaner, like the kind they use in shops. my car runs rich, but i dont have a probalem with it bogging down.

 

any other things I can look at that will help with this bogging down issue?

Has anyone ever heard of this occuring and what would cause it?

 

A hesitation off the line can be caused by a lot of things, 'running rich' is not necessarily one of them

When did this problem start. Was it gradual, or one day it was just bogging?

As for places to look, i'd point my finger at tune-up parts, TPS or some other bad sensor first myself. There is also 'tip in knock', which could be causing your ECM to be retarding timing off the line.

 

Ed,

All tune parts were replaced when all the new hardware was added last summer...not to say that I did not get a bad part though. What parts should I check first?

So you are saying that by increasing fuel pressure, this will not help the issue that I currently have?

 

Modding a broken car is always a bad idea.

When / how did this problem start and how severe of a bog are we talking about. All i know right now is something is wrong with your car, but not even vaguely enough detail to hazard a guess. For all i know this started last weekand you got a bad tank of gas, knowwhatimean, if you want troubleshooting help over the internet, you need to describe your problem in great depth, remember i can't see, hear or feel what you are.

 

If I sit at a stop light and hit the gas pedal, the car seems to hestitate like I just shoved 20 gallons of gas down it with no air to breathe. It will hesitate for about a second and then catch up and react and go.... I have been guzzling gas like crazy (yes I know its a big motor) but it seems to be disppearing very rapidly.

Hit the gas, loss of power, then it wakes up and goes. 28,000 original miles on motor. Modifications were done because guide plates on heads were leaking and blue cloud of smoke was occuring so since I had to have the heads redone, I thought now was a good time to do the mods listed below.

I am stuggling on what else to tell you. What specifics do you need and I will get them...

 

When did this problem start?

How badly is your gas mileage down?

Does it otherwise run fine or does it seem to be generally down on power?

Does it happen when hot or cold, or both. Does it get better or worse when the car is hot / cold. Does it matter what the weather is. Does it matter how long the engine has been running.

At this point i'd guess i am looking at one of a few things, either your ignition is weak, your TPS is shot, or the MAF is starting to get flaky. Of course there are always other things as well, and thats why i want to know every little detail you can think of.

Diagnosing driveability problems over the internet is always nearly impossible, and if the best description you can give is that it hesitates from a stop and gets bad gas mileage there is nothing i can do except tell you to start throwing money at the car and hope you replace the right part before you go broke or go crazy. And you'll really hate yourself if after spending $1k in parts you find a vacuum leak or a frayed wire.

At this point you need to check EVERYTHING. I'm talking pulling and reading plugs, ohming out the plug wires, inspecting the cap and rotor and really the whole distributor, checking for vacuum leaks, wiring connections are on and good, make sure the TPS is set and working, your CTS is OK, etc. If you don't know all of that stuff checks out, how will *I* know if they check out, knowwhatimean.

 

First off, me giving advice is like the deaf leading the blind But first things I'd check is your fuel pressure and your spark plugs. Maybe replace your fuel filter. It did wonders for my car.