Stock 84- bogs down & backfires

[High Roller]

I need all the help I can get. My 84 is bone stock with 79000 miles. It's not driven much, just a weekend cruiser. This morning after leaving home in it, it started to bog down and backfire when I tried to accelerate hard. The car has been sitting for about three months because I've been getting it ready to paint. I had the same symtoms a couple of years ago and replaced the gas tank, the in tank fuel pump unit (I know it's not the pump, but don't know what it's called) the fuel filter, and even the ignition switch. The problem only happaend when the car had half a tank of gas or less. Guess where the guage is now. Yep, half a tank. When it does this, if I pull over to the side of the road, cut the key off, and restart it, it will pick up and run ok for a few miles before it starts doing it again. Does anybody out there know what is wrong? Oh yeah, when I accelerate hard, the boost guage goes up to about 10 lbs and when it backfires, immediately drops to 0. Thanks.

[SVOeric]

the 84's have 2 pumps, the one in the tank (low pressure), and the one on the framel rail (high pressure) It could be your other fuel pump is going south..

or it couild be you have a injector that is about to bite it.


It does sound like a fuel related problem, or possibly something strange with the VAM ??

[High Roller]

Thanks for the thoughts on my problem. I've run out of time to get into it this weekend, so I'll tackle it as soon as I can. Until then, just keep those cards and letters coming.

[svono50]

Perry, I have a couple of questions to add to the points Eric already brought up. Are you sure the ignition system is in a "good" state of tune (i.e.- plugs, wires, cap, rotor, etc)? What is your ignition timing set at, should be 10 deg BTDC. Did you get a bad tank of gas? Are you still running the stock disty and TFI? Just a thought that your PIP sensor (inside the disty) or TFI may be on their way out.

Any of these things can cause problems like what you are seeing. You just need to go through things one-by-one to eliminate items. Good luck.

[SvoTy]

Re: Stock 84- bogs down & backfires

Originally posted by High Roller
I need all the help I can get. My 84 is bone stock with 79000 miles. It's not driven much, just a weekend cruiser. This morning after leaving home in it, it started to bog down and backfire when I tried to accelerate hard. The car has been sitting for about three months because I've been getting it ready to paint. I had the same symtoms a couple of years ago and replaced the gas tank, the in tank fuel pump unit (I know it's not the pump, but don't know what it's called) the fuel filter, and even the ignition switch. The problem only happaend when the car had half a tank of gas or less. Guess where the guage is now. Yep, half a tank. When it does this, if I pull over to the side of the road, cut the key off, and restart it, it will pick up and run ok for a few miles before it starts doing it again. Does anybody out there know what is wrong? Oh yeah, when I accelerate hard, the boost guage goes up to about 10 lbs and when it backfires, immediately drops to 0. Thanks.

Sounds like the fuel line on the intank pusher pump is split and letting air into the system. Also you might have a pinched fuel line on top of the tank.

An easy way to find out would be to go to Sears or someplace and buy you a fuel pressure gauge and drive the car and see what the fuel pressure does.

This is kind of a 50\50 deal because the ignition pick ups are really bad about going out like Ted posted.

Ty