Friday I was driving on the highway when I lost all engine power. Felt like it was fuel starved, when I depressed the pedel it just bogged down. It would idle fine. I also got some surging. Then the check engine light came on (a little late IMO, no sh@t there was a problem). This also happed on a lesser scale when I was going up a steep hill (15% grade) for about a half mile last week in Vermont.

I pulled into a service station and shut the truck off. There wasn't a mechanic on duty so I had to head to the next station down the road. The truck started fine and the engine light stayed off. It seemed to have its power back but still acted funny on the highway once in a while. The next service station was useless, they said anything could have happened and without a check engine light on and a code to chase down they couldn't help.

I checked the superchip to make sure that it was still seated properly. I also changed the fuel filter, it seemed a little obstructed when I blew through it (I know not a smart thing to do but I had to know if it was plugged). The new one was much less restrictive.

I also checked for any vaccume leaks, as best as I could visually.

It seems to be running fine now, am I missing anything?
Is there anything else that I should check out?

Any help would be appreciated.

 

The problem, unfortunately, could be normal. What were the outside temperatures when you were driving?...were you stopped waiting for a light to change or were you in slow (less than 10 mph) traffic?

I had this same exact problem last year driving through the Mojave Desert with outside temps at 105 degrees. I had to stop at one major intersection idling in drive for at least 3 minutes before the light changed. When the light changed, I depressed the accelerator and the engine bogged...so I floored it and it didn't make a difference. After moving down the road about 600 yards, the engine started to respond again. I figured the under-hood temps built up real high which added to the high temp fresh air being pulled in through the fender well and into the Intake Air Temp sensor. The sensor then sent a signal to the computer and the computer in turn retarded the timing. One symptom that you had, that I didn't, was I had no "Service Engine" light come on.

If the temps were high, you might have your Ford dealer install the new program into the computer that addresses poor engine performance in high ambient temperatures. The Tech Service Bulletin (TSB), which was issued last month (June 02), was issued to address the influx of complaints.

I also think that, on the Triton engines, if the coolant temperature (sensor in the block) reaches a high level, the computer will shut down 4 of the 8 cylinders to prevent further overheating. After running on 4 particular cylinders for a while, the computer will shut those down and alternatively activate the other 4 cylinders. Running on half of the cylinders will also make you scream "P.O.S. truck!" when you're in B.F. Egypt. However, if my memory serves me right, when the computer does a shut-down of the 4 cylinders, the engine light stays on until the computer is reset. I think the info on this is in your Owner's Manual. Check it out.

I hope this helps you out.

 

No, it wasn't hot, 75 deg. outside temp and I was traveling at about 70 mph on the highway the last time it acted up. I felt a jerk, very subtle. I do not drive with my radio on so I am always listening for odd noises and am pretty tuned into my truck.

I then felt a slight surge and then it would not accelerate. I couldn't maintain a speed above 60 mph. If I gave it more gas it would bogg down and almost buck. When I exited the highway and had to merge onto a smaller street it was very difficult to get it to go, bucking and all. The engine couldn't take more than 1/8 th throttle.

It never back fired, no smoke came out the tail pipe, and it never pinged.

Any other thaughts would be helpfull. This was the first time that I felt the truck may let me down and may not be reliable.

It is a '98, 5.4L with 76,000 miles on it but looks brand new (and used to run better than new), check out my gallery.

 

I am stumped.

Possibility:

There may have been a vacuum build up in the fuel tank. A plugged tank solenoid/vent would cause a negative pressure to build to the point where it hampers/offsets the electric fuel pump to deliver high enough pressure to the injectors. Do you remember how much fuel you had in the tank when it happened?

 

kpaton,

I think you fixed it. In your post you said that among the things you did, you changed your fuel filter. And you have not had the problem since if I understand you? I would have pointed you to the fuel filter myself.

 

Tall Tom,
I hope that you are right, it ran fine this morning on the way to work.

Area 52,
I had 3/4 of a tank full of gas.

Thanks for everyones help.

 

You may have bad coil packs. Just a guess.

 

Those are also suspect. Has anyone replaced them here and what should I expect to pay for parts? Are there aftermarket products available or shoud I go the dealer to buy the parts?

 

I would'nt trust aftermarket parts all that well. That's just my opinion though. I think if it is the coilpack(s), you would be better off letting a dealer check it and replace the pack(s) with factory certified part(s). It may be just one bad coilpack or it may be 2 or 3 or more. Heck, they might be ok for all I know. But it's worth having them all checked out. IMHO.

 

Next time it happenes, pull the chip. If it runs fine you have a connection problem with the chip. If the contacts were not properly cleaned some of the conformal coating will slip down into the connectors and can cause this. Yes it can happen after a few years. Another thing to check is the lip on the PCM mount to see if it interfears with the chip seating properly. This problem ususally results in a stall. BTW if you remove the chip make sure the truck is off and the keys are not in the ignition. This prevents the accidental "leaving it in run when removing chip" problem.

Regards

Jean Marc Chartier

 

O.K. it happened again. WOT 1 to 2 shift at 5,400 rpm, 10 seconds later after letting off the gas just after the sift the check engine light came on and lost all engine power.

I was able to get it to the side of the road and shut off the engine. Waited 30 seconds and turned it back on. The check engine light stayed off and it runs normal. I haven't tried another WOT shift.

This is sounding more like a superchip problem??????

I will pull the chip tonight and wipe down the connections to see if that is the problem.

I haven't checked tha coil packs yet and I am trying to avoid an $80 bill for downloading the codes. Any other suggestions are welcome.

 

kpaton,

Yes...it sounds like a bad connection on the chip. However, wiping it down will not fix this. You need to use a magnifying glass and a very small standard screwdriver to scrape the additional conformal coating on the contacts and especially between the contacts. That's where I had my problem. I had a couple of high spots of conformal coating between a couple of contacts. The only way I could see it was under a maginifying glass with a bright light. I very carefully used the corner of the small screwdriver to scrape the coating off. Warning Will Robinson!: Do not scrape the contacts too much. Check each contact by lightly dragging the screwdriver and closely watch to see if you get any additional coating off of each. If you scrape too much, you will see the copper show through the silver coating.

Of course, you must take the 4 screws out on the computer and un-sandwich it to gain proper access to the computer board contacts to do this.

 

Just talked to Mike T. at Performance Products and I think that we have ruled out that this may be a problem with the superchip or installation.

Went to AutoZone and had the codes scanned, pretty short list because there were none stored. The odd thing is that it should have come up with a ROM error code #P605, I thaught that this would always come up if the chip was left in while the codes were being scanned.

Any other suggestions?

 

Hmmm...if you "should" have a P605 code and did not, then wouldn't you think there is no proper contact on the chip at all? I have no insight/knowledge on this code though.

Why is Mike ruling out a chip connection problem? Is it because you did get it to idle, but with a surging? Usually, you can't even get it to start again if it is a chip problem.

I would pull the chip out altogether like JMC stated above. But leave it out for a week or two to rule out anything else.

With 76,000 miles, is there a possibilty you have carbon build-up in the EGR ports which would cause surging and rough idle?

 

It is starting to sound like a coil pack to me too.

Before you start swapping it out maybe it would be money well spent to do an on board diagnostics with an OBD computer interface. I don't know all the makers that are capable of doing this but they have routines that you can run with engine running that would check the general health of the coil packs. Of course if they don't fail at idle or anything less than heated up at WOT it may miss it, BUT there is at least a decent chance that it could see some condition that was out of range to help confirm it.

I hesitate and hate swapping s*** out just cuz you think its worth a try. It can get expensive and it can also introduce more variables the aggravate you even more.

The fact that it is only at WOT, or at least that is the impression I have from this post, does seem to make one think that the computer is getting a signal or losing one or thinks it is and is trying to protect things. Just thinking out loud here.

I am not that familiar with how the manual transmissions and the rev sensing circuit works, sorry. I haven't had to deal with this up to this point.

Spend a little money to get a complete diagnostics run and see what shows up...OR......just don't drive it at WOT anymore...:-)