No throttle After 15 Minutes

[treblig]

I am out of deals on my 302, please help!!

I have stock 5.0 with less then 2000 miles on the motor. I took off almost all the sensors that I could to keep the car to run correctly. I have the O2’s, ACT, BAP, no EGR, I am on a three pulley system, no power steering, AC, or air pump, no WOT or BAT (?). I have 3/8 fuel coming out of tank to a -6 fuel filter (Summit 10 micron) to a Holly fuel pump then to the 5/16’s stock 5.0 fuel line then to the injections. Inside the tank I have a 1969 Camaro tank with a 69 sending unit, pick up tube is 5/16. The tank has been coated with POR 15 tank coating.

Here’s my problem:
When I start out the car runs great, jump on the gas and the tires break loose, engine temp is 0 to 100 degrees. After driving the car for 20 to 30 minutes, engine temp is 180 and the oil temp is 190, outside temp is 34 degrees. When I go to give it gas the car just dies, you let up on the gas and the car runs but you have to give the gas very easily. After 30 minute you really have to play with the gas and baby the pedal to make it back to the barn. The first time this happen I dropped the tank and coated the inside thinking of rust and corrosion. That’s done, drove it again same thing. So I dropped the tank and found out that the pickup tube has a screen and there is a crease right where the tube ends so I thought that the tube was sucking up the screen so last night I cut the screen off. Put the car back together and went down to the DMV today (they were closed due to the weather) to get my license tabs. On the way back the same thing, car dies until you let up on the gas and baby it.

The fuel pump is an old Holly inline, when they first were doing the 5.0 conversions, 1993. Also the pump is pretty quite at first; 15 minutes later you can really hear the pump (at a stop light) next thing the car is dying.

Before I go out and spend 250 for a new pump, I wanted to see what you guys think. I want to think it’s the pump however I am thinking it might be electrical, stock coil and distributor, motor gets to temp and you heat expansion could cause gaps in solder joints I know if it’s electrical I could be chasing this for weeks and drain my savings account for my paint job. I am so close.

[MJN]

Did you check to see if you have any codes?

See if you can borrow a fuel pressure gauge that will screw into the schrader valve on the fuel rail and check the fuel pressure.

Usually if it's electrical on the ignition side you don't get those type of characteristics. I've had both the TFI and PIP go on mine and they both start by exhibiting misfiring at higher rpms before completely cutting out. Electrical usually results in a misfire of some sort it didn't sounds like you though you had a misfire.

One other thought, where do you have the EEC (computer) mounted? If it overheats it could cause issues.

[AustinSnake]

You can get a fuel pressure gauge from the Autozone tool loaner program. You can keep it for 60 days and take it back for a full refund. Make sure it has a Ford shredder valve adapter. See if the pressure is acting up when you have the problem.

[Doug Meldrum]

I had a similar problem and it was the injectors. as soon as it warmed up it was much worse. I had a couple that were clogged and the rest were overcompensating for the lack in the cylinders that were clogged (dripping, no mist). The intake smelled like it was flooding and it was blowing black smoke. I had 38 lbs. of fuel pressure. The injectors had over 100K miles on them. New injectors and it runs great!

[Big Blocker]

Treblig,

You say you have some of the sensors, did you by-pass the rest or just disconnect them. I'm assuming that you have the EGR by-pass resistor setup and that the TAB / TAD has resistors where the coils used to be, right? Also, check your TPS for being set to high when cold . . . unit will heat soak after a short drive and send back false readings to the EEC, causing the system to run erratic . . . same with water temp and air temp sensors, without them runs bad due to erratic info being sent to the EEC.

HTH

Doc