Let me just start by saying that my car used to run fine... and there is nothing new other than my car sitting for about a week while I put a dual electric fan setup on.

Still battling my hesitation problem. I checked my fuel pressure and it was a little low. I called Ed Wright and he told me to put it at 45 psi without the vacuum attached. This helped the sitting in the driveway and nailing it problem. It used to spit and sputter and get all choked down, now, it revs normally with the exception of occaisionally a slight hesitation.

But, going down the road, I give it gas in any gear (4spd) and it hesitates on acceleration. If I am in 1st gear... its starts out stumbling.. then gets so bad there is no repsonse... but as I keep pressing the accelerator, I get to a certain point that everything just kicks in and the tires lite up, and I'm going again. In My opinion, it feels exactly like the TPS has a large dead spot in it, although I get no error code, I checked it manually. I put a meter on it and watch it sweep all the way from .54 volts to over 5 volts. Absolutely no "erratic" operation. It climbs very steadily... so I have ruled this out.

I have 2 mass air flow meters, and have tried both. Both yeild the same affect. I have bypassed the supercharger, and stuck the mass air flow meter right on the end of the Throttle body, and still the same effect.

The oddest thing is, I can go for an hour drive... and 20 minutes out of the drive, its running OK, and there is no hesitation in accelerating. The other 40 minutes of the drive its cutting out, choking down on acceleration. It seems to do fine at idle, and OK at wide open throttle.... its just getting from one to the other that messes up. While its doing bad, I can just cut the ignition for about 3-4 seconds and coast, then turn it back on... and the car is running fine again... for about a minute. I wonder if the car likes being in open loop better than closed loop?????

I hear there is another box near the ECM on an '85 model... that has something to do with the MAF meter... does anyone know anything about that?

I am buying an O2 sensor today after work, they are cheap enuf to try... but I do not have the resources to constantly be throwing parts at it. If any of you out there have owned and '85 and had a similair problem... I would appreciate any help.

 

I'm no expert with SC's, so i dont know if it could still be affecting things while you drive.

The thing with the MAF sensor is your burnoff/power relay, on 85s they buried it in the dash. Wouldnt be a bad idea to replace it but i'm not sure its the problem.

Only thing i can see is that maybe youre not gettin fuel/spark to all the cylinders. So id check the injectors, plugs/wires/distributor cap. Check for other vacuum leaks, and make sure the TB is clean.

It shouldnt be the 02 sensor, that would show up as crappy fuel mileage, not cutting out at speed.


[Modified by vader86, 1:20 PM 9/3/2002]

 

I'd suspect something with your fan setup. I'm assuming this isn't stock by the sound of it. How was it wired up?

I'd disconnect it and see what happens.

 

Duntov is right.Rewire your fans. :chevy

 

Clogged fuel filter? :confused: