Ok All You Efi Gurus, Here's Your Chance To Help

[D.Hearne]

This past weekend my 95 E150 van developed an occasional "stumble". It was like it lost electrical power to the engine suddenly for a split second. Did it three times in a hundred mile trip. Then this morning it did it again, but this time it cut out for a second or so, and this happened 3-4 times. This evening, on the way home, it ran flawlessly. Motor is a roller 351W,( speed density system) never been touched, only tuned up a couple times. 150,000 miles on it. Plug wires are Ford Racing 9mm and are a couple years old, ditto for the plugs, cap and rotor. All other parts on it are the original pieces. Any one got any ideas?

 

[bnickel]

ignition switch. if the key cylinder is kinda loose in the column it will cause that exact problem. my uncle used to have a 93 e150 with the 351 and it would do the same thing. also had similar happen with my 73 galaxie and my brother had it the worst i've ever seen with his 83 tbi v6 stang. just a thought i would check it sometimes just wiggling the key when it does that will fix it right up. you eventually get a feel for where the key needs to be to prevent this.

another thing to check is the coil, the TFI coils are bad about that.

 

[Loup-garou]

Check for electrical system Technical Service Bulletins and/or recalls on that van. There were some problems with the large pickups and vans involving the "multi-purpose switch" in the steering column; though I'm not sure if that year was included.

 

[Hack]

Did the computer set a code? If so, getting the codes read is the way to go. IMO this is a job for a competant dealer. Throwing parts at it gets expensive very quickly. It could just be a bad ground or a loose connection somewhere in the harness. I believe that dealers also have the capability to hook a data recorder up to the engine (if no code was set) and then you can drive it until the problem happens again. Then they read the problem from the recorder and fix you up.

Good luck.

Edit: once the dealer finds the problem, you can save some money by removing and replacing the parts yourself - depending on where the problem is located. This is how I generally handle this type of problem with "newer" vehicles from the 80s and 90s.

 

[D.Hearne]

Well it very well could be the ignition switch, that's been loose for some time. Sometimes you can actually start it up without the key in it. The coil? Maybe so, It's got the second third one since new. Second one was an Accel coil, it didn't last six months. My kid also suggested hooking it up to an OBD to check for faults. He works at the local Advance Auto Parts and we're going to do that today.

 

[88 Fox GT]

Hook it up to a code tester. Or ground the STI and read the flashes of the check engine light.

It could be one of many things right now. Dirty injectors, aging TPS, ignition switch, or something in the ignition system.

 

[D.Hearne]

Ok, Went to town in it this morning, played with the ignition switch all the way there, nary a hitch. Tried to hook it up to a code reader and got no response, like the harness to the computer wasn't plugged into it. What's the STI, Speed Demon?

 

[68rustang]

my old truck did the same thing once. It was the fuel pump. Check your fuel pressure.

 

[Hack]

Ok, Went to town in it this morning, played with the ignition switch all the way there, nary a hitch. Tried to hook it up to a code reader and got no response, like the harness to the computer wasn't plugged into it. What's the STI, Speed Demon?

This is the absolute worst kind of problem to have. Doesn't set a code in the computer, but could leave you stranded at any time. I'm not sure what the cost is, but I think you should find out whether a local dealer will let you drive around with a fault recorder.

Or just keep driving until the failure strands you. At that point the dealer could diagnose it more easily.

 

[D.Hearne]

This is the absolute worst kind of problem to have. Doesn't set a code in the computer, but could leave you stranded at any time. I'm not sure what the cost is, but I think you should find out whether a local dealer will let you drive around with a fault recorder.

Or just keep driving until the failure strands you. At that point the dealer could diagnose it more easily.

This is what I'm afraid of. It's exactly that kind of problem. If my 06 Stang was here, it wouldn't worry me too much. I've got to drive this thing to work, Friday thru Monday. The Friday drive is 105 miles, one way. The Sunday & Monday drive is only 28 miles one way. I pulled the K&N filter and cleaned it yesterday, it was dirty, and maybe that was the problem. It had this same thing happen when fairly new once, but with a paper element.

 

[pabear89]

This past weekend my 95 E150 van developed an occasional "stumble". It was like it lost electrical power to the engine suddenly for a split second. Did it three times in a hundred mile trip. Then this morning it did it again, but this time it cut out for a second or so, and this happened 3-4 times. This evening, on the way home, it ran flawlessly. Motor is a roller 351W,( speed density system) never been touched, only tuned up a couple times. 150,000 miles on it. Plug wires are Ford Racing 9mm and are a couple years old, ditto for the plugs, cap and rotor. All other parts on it are the original pieces. Any one got any ideas?

Sounds like Fuel pressure problem.
try replacing the fuel filter and check condition of air filter also.
when my 89 F250 7.5 started doing that it was low on fuel pressure from dirty filters.

PB

 

[D.Hearne]

I'll try the fuel filter, I changed the pump about 6 months ago, I don't recall messing with the filter then though.

 

[68rustang]

LIke I said earlier my old truck, 95 GMC SOnoma, 4.3 L TBI. Had a very similar problem. It would intermittently stumble. I checked all the ignition, changed the plugs, cap, rotor and wires, replaced the Fuel filter, checked for vacuum leaks, all the easy stuff. It turned out to be the pump going bad. It needed 7-9psi to run properly, the pump was making about 4psi. Get your son to borrow a fuel pressure gauge from work.