Hi.
I went for a drive to run some groceries. As i pulled out onto a busy road and gave some gas i heard and felt a clunk like i sometimes get going from R to D within a few seconds it hesitated so i gave it gas. Good thing there wasn't anyone in front of me. Within 1/4 of a mile i made a right turn at a light went up a small hill when my truck just shut off. I pulled over to the side of the road and put it in park and turned the key off. I waited about 30 seconds and restarted it with no issues. I drove up the small hill and turned on my street. As i pulled over to the side of the road to get ready to pull out into traffic it shut off again. I decided to bring my groceries in, giving the truck a 15 minute break. I sat back in my truck, started it and reved it to about 1200 without any issues. Since my road isn't a busy road i decided to cross the 2 lanes to back into the driveway. I pulled out onto the street, put it in reverse and it shut off again. I tried to start it and it just continued to turn over without any sign of fuel. I got out and asked a neighbor to help push me into driveway and he went and got his son. We were about to push it and i turned the key and it started so i quickly pulled into the driveway.
once safe in the driveway i held my foot on the gas keeping it at 1200 for a few minutes. Let go of the gas and it drops to about 900. Within a few seconds i notice the volt meter jump slightly then drop by a 1/4 and a few seconds later my check engine light goes on. I put my foot back on the gas at 1200 and check engine light goes off and volt meter goes normal. I did this a few times and the same thing happens.
Any idea what my electrical issue is without me having to buy a lot of things i can't afford.
Any help would be fantastic.
sorry for the long read but hopefully it's an easy fix.
1990 f150 automatic. Fuel injected.

 

what engine. any codes and have you done any work on it recently.

 

Hi.

 

Hmm this wouldn't explain the clunking but I've had similar issues before on my Bronco when it was a 302 due to the ignition system.

I believe the distributor in your truck (5.0/5.8 I assume?) is very similar to what was in my Bronco, and the PIP sensor (which is mounted around the shaft of the distributor) was failing. It would cause my Bronco to randomly stall out, or sometimes not start at all. It could be something like that. IF it is, it's easier to replace the whole distributor than it is to try and disassemble the distributor and put in a new sensor.

Also, I believe your truck will have a distributor mounted TFI module. They are notorious for overheating in that position and causing all sorts of starting/drive-ability problems such as the ones you explained. Those modules can be tested, but don't always test bad when the are bad. You'll have to have them tested multiple times so they get hot in order to get a proper reading.

 

hi. Thank you i will go see if i can figure out how to pull the distributer out and look in hanes to see what the sensor looks like and mounted.
i normally get the clunk from shifting from R into D or back. Being a $900.00 truck some things i am forced to live with. I'm told the gears in my rear-end are loose and this is quite common. The clunk i can live with i just slow shift from R into D. But for it to clunk while driving forward was strange for me.

 

pull codes and check fuel pressure with a gauge.
both are easy and free and can provide valuable clues.

 

Clunking can come from many things. I don't believe it would be related to stalling/no start. I would recommend checking your u-joints on the driveshaft too see if they are cause of the clunk. If they are worn out, they could be pretty loose causing causing clunking when shifting into forward or reverse. You can check this by grabbing the driveshaft between the joints and trying to shake/move the shaft. If there is any play in the joints, they are bad.


I would also recommend pulling codes and checking fuel pressure.