Automotive Question

[BLUEJEEPLAB]

SWMBO has a Ford E150 with a 302 that has a low speed miss. It is fine when cold, runs fine when the revs are up (60 or better on the highway) and has great pickup when you throw the boot into the throttle (no miss then).

I get NO codes on the analyzer, has new plugs and wires and a new Oxy sensor. My thoughts have been Fuel issues or Cat Converter, but those options don't make sense with the good high speed performance.

Coil maybe? Anyone ever experience this?

[dale_1]

darn fords

The thing about the coils in that particular application is that they usually cause a miss at every rpm range and at odd times... and... they usually set the service engine light...not very helpful huh?

How's your fuel mileage? when's the last time the filter was changed? I know this is gonna sound odd..... but if you have a bit of a restriction in the fuel filter your mileage goes down and it often causes a low miss.

Boot in the throttle will help clear the miss only because then it isn't getting starved.... efficiency suffers but delivery is still there albeit a little lower than it should be.

I don't believe it's a coil issue..... looking through my TSB's right now and don't see anything to help. Will keep checking through them but there are alot of Tech Service Bulletins it being a Ford (just teasin)

"more input"
year
mileage
last fuel filter change
who did the plugs, wires, O2 sensor
any smoke? specifically white

I will consult my Ford guru for further information tomorrow. I worked for him for awhile and he always helps me if I see something odd. He has been at the top of the heap with Ford for so long I think he's probably gotten dizzy over the years!

[The Lorax]

Could be valve seals, I have a GMC with the same issues, minor differences in where it manifests itself but a similar "random misfire" mine does show engine codes, I have been chasing it for some time and now I have finally come to the point where I need to just R&R the valve seals and see if that finally does it.

[BLUEJEEPLAB]

year 93
mileage 135K
last fuel filter change Unknown
who did the plugs, wires, O2 sensor - Me
any smoke? specifically white No Smoke

The fuel filter was also one of my suspects, I'll tackle that this weekend. I'll have to swing by Ford as it looks as if the "T" bolts that hold the Gas tank hangers won't survive the removal. They are very rusty.

[Czekus21]

You may also need to pick up a special tool to get the fuel filter off. This can be picked up at just about any auto parts store. The tool fits over the fuel line and then you have to put pressure toward the filter to release a line type of lock. While putting pressure on the lock, pull the line out, away from the filter. Make sure that you relieve the fuel pressure BEFORE pulling the filter. Don't ask how I know that but it's a wonder that I don't wear glasses yet.
This type of tool that I described was needed for my 95 F-150 with a 5.0 (302). On SWMBO's 93 tempo, was just clips that locked the filter. 3.0 V-6.

[DiverRay]

The fuel filter on the truck SHOULD be in the right side frame rail, just about at the back of the cab. I don't think you need to remove the fuel tank, but I could be wrong. It does happen now and then.

[dale_1]

E-150

That isn't a typo is it?

Van not truck right?

[DiverRay]

You are correct, it should be a van. Filter should still be in about the same location, just near the side door, not the back of the cab.

[dale_1]

course, here I was thinking driver's side....

I am getting a little old though so it may be the Right side!

[TADracer]

If your gas mileage sucks too, check the vacuum module & switch for the EGR valve. Had this on my 01 Crown Vic, no error codes and made me do alot of curseing. Cost all of $9.00 to fix.

[BLUEJEEPLAB]

It is a van and filler neck is about 4 feet behind driver's door. It's a Custom and has a 42 gallon tank. I am driving it to work for the next three days to get it down close to "E". I was planning on using the Motorcycle jack to support the tank to lower it.

You guys may be right, I think I recall seeing a filter on the frame rail when I was under there earlier. However, that doesn't save me from dropping the tank. The rubber hose from the filler to the tank is dry rotted and leaking too when the tank is full.