pontiac86ta

My car is:
86 Trans Am
305 V8 with a Rochester Quadrajet

This 'ole car has been a headache the past couple of months! So here is the history...

It started out that when I would make a short trip, stopped for a few minutes and try to start back up, it wouldn't start. It acted as if there was no fire. If I would let it sit for a few hours, it would fire fine. We chased that and replaced the rotor button and the problem went away.

Right as we put the distributor cap back on and fired it off, it had BAD hesitation. I couldn't even pull it out of the shop without dying. Sooooo, off with the carburator. And sure enough, the accelerator pump was torn. We then found that the former idiot who rebuilt the carburator before I had the car didn't put the additional pieces back on the accelerator pump (the clip and big spring thing). Luckily I have a donor carb and stole the pieces off of it. We did a thorough cleaning finding all the pieces of the torn pump in the jets. And we replace the fuel filter as well. We put a rebuild kit on the carb and before we put it back on, we noticed then intake bolts were loose. AH!!

We take off the intake, put on new gaskets, seal her back up, torque down the bolts...again...put the carb back on, the horrible hesitation is still there!

Well, we take the carb back off checking everything to make sure we didn't miss anything. (Actually we took it off several times questioning weather things were right or not). We then think it might be the fuel pump. We put on a new regular fuel pump, no avail. So we try an electric fuel pump, no change. ARUGH! Since the electric one didn't work, we just put back on the new manual fuel pump.

After that we unplugged the jets and see what it would do. It ran like a champ, minus the ungodly amount of fuel being burnt. I could mash the accelerator to the floor and it was get up and go! We would plug the jets back in, and we were back at bog central.

During this time, the check engine light was on and our code reader is a piece of junk and won't read my computer. We put the lil key in and just check it that way by reading the flash of the lights. Well, the check engine didn't flash. So I went and bought a new computer. It is now installed and with the key in it will flash the check engine light. It told us the ignition module was screwed up, and it was indeed completely dead.

We changed the ignition module, let the car get up to operating temperature set the timing and went and did a road test. It ran like a champ! I was so happy to have my car back!

Until this morning....

I get to the highway and the car is barely off 100* (it's a short trip to the highway, so this is normal). I pull out and I have no accelerating power. It's crawling like it's on it's last leg. I keep limping it down the road and try to accelerate a little when I would run down a hill. It finally gets up enough momentum I'm okay with trying to keep it rolling.

When the car reaches about 180*, it runs fine. Not like it should, but it runs fine. It still has a bit of hesitation though when at full operating temp. At least it is running better than it was before all of this work.

Now, when we road tested it the previous day, the engine temp was about 210* (I have a 195 thermostat). With that too, my fan doesn't come on either, but I can force it to come on by turning the a/c in the car.

Summary of what's been replaced:
New intake gaskets
Carb rebuild (accelerator pump, gaskets & fuel filter)
Fuel pump
Rotor button
Ignition Module
Computer
Even went as far as disconnecting all that smog crap and plugging the vacuums to it.

What is causing my car do have no power at acceleration when the engine is cold? And still have hesitation when the engine is at operating temp?

Ozz1967

iTrader: (4)

What's your fuel pressure? You have an electric pump in it, you must not rum more than 6.5PSI or you'll flood out your carb. Have you changed the fuel filters?

Have you pulled your plugs to look at them? Are they wet? Are they burnt?

have you changed your plug wires? They could have shorted to the heads/intake, or juts about anywhere and causing loss of spark. have you changed the cap and rotor? if the cap goes bad, it can cause spark flash internal to the cap, thus shorting out internally when it's trying to fire.

Is this a CC qjet? I am assuming it is. When you set the timing, did you disconnect the distributor from the ECM? (Four wire flat connector coming off the dizzy). Factory setting is 6* btdc.

If you did this, did you blow the ECM fuse? Check under your dash. If the battery isn't disconnected on my 84 CC Qjet, I find I blow this fuse every time i disconnect that four wire connector I set my timing. So when I set my timing, I just pull the fuse now instead of disconnecting the Dizzy. Hope this gives you some ideas on where to start.

pontiac86ta

It doesn't have an electric pump. It's a manual pump. We've tested the pump and it's fine. The fuel filter is new.

Plugs are fine. Plug wires are new. The cap is fine and the rotor is new.

CC Qjet? I assume you mean computer controlled? We've set the timing several times before. The magic number for my beast is 8* from TDC.

The ECM fuse is fine as well. I checked that when I had computer problems and ended up replacing the computer. Now, as for you having to disconnect your computer from the battery when you set a timing, sounds like you have a ground messed up somewhere. I'd double check that sucker.

Thank you for your help though. I'm going to double check the timing hopefully this weekend. I've fixed/replaced so much on that car recently that you'd think it would all be fixed by now. But I think it just likes the attention.