I have an 88 E-150, 4.9L, 124" WB, with 303K miles. First hot days here in GA. Day before yesterday, when hot, it drove as if it was starving--intermittent throttle control. Thought it was fuel related. It stalls and will not re-start until cooled. Runs fine after cooled, as if nothing is wrong. I have replaced the fuel filter and have purchased new internal and external fuel pumps but have not installed, thinking that it might be vacuum (or other) related. Any ideas?

 

Sounds more like your TFI Ignition Module on the Distributor is going bad.

 

Thank you. I will replace it and will test with a drive to Nashville tomorrow. New plugs, wires, rotor, cap--while I am in there.

 

I wouldn't want to test out that theory on a drive from GA to Nashville if it has been stalling. I'm going from Macon to Tullhoma, TN tomorrow. If I see you on the side of I 75 or I 24 I'll stop.

 

I have replaced the TFI ignition module, the coil, new plugs, wires, cap, rotor. New external fuel pump, internal pump and sender assembly. New fuel pressure regulator, ISC valve. After about an hour of driving in hot weather, it stalls and will not start for fifteen minutes. Then will run for another hour before stalling. This morning, less than a mile from the house, it stalled on making a right turn. I coasted it to the curb and it resatarted and drove fine for the 45 minutes it took to get to Atlanta, with some strange gas gauge activity. Any ideas? Re-cap: 1988 E-150, 304K, 300ci, no a/c, 124 WB. Thanks.

 

The vac lines crack from the heat over the passenger side exhaust manifold. The vac reservoir "coffee can" behind the battery will corrode and leak.

Typically I can't see where a vac leak would make such a distinct response only in hot weather, but it's hard to predict and this area probably needs to be reworked anyways. It's easy.

Oops, I thought you had a 302. I see you have a 4.9L. May or may not have the same problem.

 

Thanks. Will check again, all "looked" good, age may dictate. What else? Computer? Bad TFI Module? Sensor?

 

When you replaced the TFI Module did you use heat transfer compound?

How hot is the engine running, you may need to check the radiator.

Are you running the A/C when this happens?

The Computer, maybe but not likely, yours is inside under the heater.

You need to find out if it is fuel or spark that you are loosing. Get one of those round dial type tire gauge form a parts store that will check your fuel pressure, some will and some will not. Then when it dies ground pin 6 of your test connector or have someone turn the key off and on and see if you are getting fuel.

For spark get a set of insulated spark plug pliers and pull off a wire and hold it close to the block and see if you are getting spark while the engine is cranking.

 

Ya, used all of the compound when installing the TFI module.

Temp is good, on the gauge. Radiator installed new 2/05.

Not equipped with A/C.

Could it be a failing coolant temperature sensor? Fuel manifold tempertature switch?

Heat from heater core effect on computer?

 

Fuel pump relay???

 

Would not cause this problem.

Not likely unless it gets real hot on the passenger floor board area.
If it is you could put a vacuum operated valve in the supply heater hose, this would also keep the inside of the van cooler in the Summer.

Not likely but to check it when it dies just turn the key off and then back to run (ON) and you should hear the Fuel Pumps run for 2 seconds. If they do the Fuel Pump Relay is not your problem.

 

Replaced the relays, fuel pump and EEC. Drove 90 miles in 80 degree weather. No cut off while driving. Yeah! Stalled in park at the store. Boooo. Started again. Yeah! Drove to park, tried to leave an hour later. Would not start. Booo. Could hear the fuel pump. Yeah! Smelled as tho it was getting gas. Yeah! Let it sit. No good, wouldn't start. Boooo. Found a can of ether, took some work to get it started. Got it home. Yeah! Re-starts and finds correct idle after 15 secs. Now what?

 

Is it a timing issue?

 

"Could it be a failing coolant temperature sensor? Fuel manifold tempertature switch?"

After rethinking this question, yes it could be the Engine Coolant Temperature sensor, this is the one with two wires on it. If your engine is hot and the EEC thinks it is cold and sets the fuel rich and timing to the cold settings it could flood out and not start for a while.
There is not any item called an "Fuel manifold temperature switch".

There is an Air Temperature sensor.

Here is some information on the ECT.

http://fordfuelinjection.com/index.php?p=28

 

Thanks.

I purchased the engine coolant temperature sensor and the air charge temperature sensor when I got the relays. Was hoping it was the relays. Will install, now.

See section 24-10, 1988 truck shop manual B, for info on the fuel manifold temperature switch.

Have a Happy Easter.