I have a 1990 f150 with 140,000. It has two fuel tanks and is a V8 (350 i believe). Anyway lately it has been acting odd. I go out to start it and it will start right away but after a few minutes it will stall. I start it up again and keep my foot on the gas to warm the engine. I release the gas and I may get out of the truck to let it continue to warm while I ready for the trip I am about to take. As I get it it sometimes stalls. So I change my plans, crank it up again, rev it up and sit in it until I am ready to go. I take off slow and everything seems fine, but then it will stall just up the street. This will go on for a few more times and then it seems to be fine. The other day I got on the highway(a little nervous because I did not want to stall there) and it ran fine until I got off the highway and then it stalled again. I started it up and finally got to my destination and turned it off. I found if I leave it running it will do better but I only do this when I in and out of where I need to be. Anyway I come out and sure enough the process starts all over again. I recently changed the fuel filter, the air filter, and put STP in both tanks and nothing seems to help. Anybody have a clue as to what this problem may be? I read that if its the fuel pump that it usually wont crank is this the case? If its the fuel pump there are two correct and woundnt act better when the other tank is engaged? It doesnt. So I am clueless. Any help you all can provide would be great.

Thanks
Jake

 

Howdy and welcome. Engine wise you could have a 302 or 351. Looky at your vin number 8th digit N is for a 302, and ummm I think H is a 351 (could be wrong on that).

Could be a lot of things, and I bet the computer has some codes stored (even without a check engine light) and you can read the codes yourself. Read how at www.fordfuelinjection.com

Adrianspeeder

 

i'll give that a shot and let you know how it pans out thanks

 

Years ago my 89 302 5 speed would do that too. It would even surge up and down and sometimes when you take your foot off the gas to make a turn it would die. Real fun with the steering. So one day I removed the throttle body and drilled a small hole in the top bufferfly valve maybe a 1/8 or 3/8 can't remember for sure ?? to many years but anyhow it stop the surging and dieing. The idle rpm is control by the air bypass valve and sometimes the only thing left to do is drill it.

Even on my 02 5.4 there's a hole in the butterfly valve too.

 

Well I bought I tried your idea and I had trouble so I found a ACTRON AUTOMOBILE CODE SCANNER CP9015 and bought it for about 20 bucks. it is the kind that beeps when you have it hooked up and have it in test mode. I hooked it up just like the book. Put it in sound mode and put it in hold mode. I then turned the ignition key on without starting. I went bak to the scanner and put it in test mode. It does not beep but instead continues one long continuous noise. I even waited up until a minute to see if this changed nothing happened it still continued to make the noise. I then turned the key off and it still made the noise. I unplugged the scanner and reinstalled it and got the same result. I unplugged it once again and turned the truck on and let it run for a minute. Turned the truck off and hooked up the unit and turned the ignition again - again the same noise. I then cranked over the truck hoping for a different response - same response.

According to the scanner manual You have two plugs right next to each other that look like the following
_
- - _ -
_
Also according to the book the scanner hooks into the truck starting with the second dash (similar to a three pronged plug) and then into the seperate plug

According to the book all the slots don;t need to be occupied because the other more expensive scanners sometimes use that slot.

I should also mention that the larger plug on the truck does not have the clip to hold the scanner on so I used electrical tape to make sure I had a firm seating between the two. I verified this everytime I took this on and off of the truck and after each test.

Given all this - What am I doing wrong??? It seems rather staight forward The scanner and battery are new and I coin tested to verify the battery and the scanner. This is so frustating. Any advice guys? All I want to do is test my truck so that I can have knowledge of what is broken before I have it repaired Thanks




it also indicated that the

 

riderman -
I don't know about your scanner but my Daddy used to refuse to even talk to me about any idle/miss problem until I could say that I had put in new spark plugs. New plugs can cure all kinds of problems, it is about the cheapest fix you can start with, and it usually needs to be done anyway. Even if your plugs are only a few weeks old - replace them if this problem started since you put them in.

Buy a Chiltons book for YOUR TRUCK (ie Ford F150 1990-96 or something similar) it will be the best 25 bucks you ever spent.

If this problem only happens when the engine is warming up look at the cold start injector system - usually an engine temp sensor or sensor wiring.

If this problem is worst when it is very humid or foggy or condensing dew, look at the spark plug wires. At night you might be able to see the sparks jumping off the wires or the corona.

Check your fuel injectors for an even spray pattern. Dirty injectors can cause what you describe.

Don't drill any holes in the butterfly valve.

Good luck and let us know what you find.

 

You can check for codes without any equipment at all by following the procedure at www.fordfuelinjection.com

What engine did you determine it to be?

Adrianspeeder

 

Well Im the first to say im an idiot - it appears that i had the code reader installed in reverse One I installed it correctly I then realized that my key ignition had to be held so that it remained in the proper location for the test; that is why i got the constant beep. Once i held it in the positon i was able to the off engine test - and that came back normal - code 11. I started it up and got the 4 beeps to indicate that its an 8 cylinder. I then did the test where you push on the gas all the way down then release. This gave me a code of 651- Electronic Pressure Control circuit failure - Does anybody know anything about this code? BTW its a 5.0 engine

Thanks
Jake

 

if nothing tech wise could be clogged cats, my bros old '92 5L 302 kept stalling and knocking of that.