98 4.6 slight shudder/stumble
#1
02-09-2007, 03:57 AM
Join Date: Nov 2006
Location: Oregon
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98 4.6 slight shudder/stumble
Ok, so a couple months ago I had real bad rough running/stubling problems along with a CEL. I was too busy to touch it for about a week and the problem went away on it's own.
About a week ago it came back. Went to Autozone and had the codes pulled. EGR flow insufficient and cylinder 7 missfire. First I pulled the TB to find both EGR ports completely blocked. Cleaned the TB out and took it for a test drive. Slightly better but still really bad. Next I swapped all the plugs and wires, reset the PCM and took it out for a short drive. Problem seemed solved.
After some freeway driving it seemed like the truck had a very slight shudder in the 1700 or so on up RPM range. Then this morning I was taking a freeway on ramp and got a stumble while in the curve of the ramp. Full tank of gas btw. There were times before when I'd go out in the morning and it would be running normal and then I'd go get on the freeway and the sharp on ramp would set it off to running like crap again. What this indicates I can't begin to imagine.
So I'm stumped at the point. I've got no more CELs. I'm romped it trying to get it to throw one but it won't oblige. I also seafoamed the engine through the brake booster vacumn the other night. The truck also had a fuel filter installed a couple months back. I've also cleaned the MAF with CRC electrical cleaner as well as all the contacts for every sensor I could find. Any ideas?
About a week ago it came back. Went to Autozone and had the codes pulled. EGR flow insufficient and cylinder 7 missfire. First I pulled the TB to find both EGR ports completely blocked. Cleaned the TB out and took it for a test drive. Slightly better but still really bad. Next I swapped all the plugs and wires, reset the PCM and took it out for a short drive. Problem seemed solved.
After some freeway driving it seemed like the truck had a very slight shudder in the 1700 or so on up RPM range. Then this morning I was taking a freeway on ramp and got a stumble while in the curve of the ramp. Full tank of gas btw. There were times before when I'd go out in the morning and it would be running normal and then I'd go get on the freeway and the sharp on ramp would set it off to running like crap again. What this indicates I can't begin to imagine.
So I'm stumped at the point. I've got no more CELs. I'm romped it trying to get it to throw one but it won't oblige. I also seafoamed the engine through the brake booster vacumn the other night. The truck also had a fuel filter installed a couple months back. I've also cleaned the MAF with CRC electrical cleaner as well as all the contacts for every sensor I could find. Any ideas?
#2
02-09-2007, 02:52 PM
#3
02-13-2007, 11:03 AM
I just fixed my problem like yours.. 1997 F150 4x4 5.4, 180k I replaced the #1 coil pack and now it's not stuttering when i give it gas. I read so many forms and it sounds like the problem is all over the engine. Some guys had all the spark plugs and coils replaced but still had problems. I reset my computer so i would not have any old codes that might throw me off. Once I got my fresh code I went to Auto Zone and they told me it was my # 1 missing. I also got my injectors cleaned $40, replaced fuel filter $10, fuel pressure regulator $60, and most IMPORTANT my PBFE (or DBFE something like that) Now it runs like NEW!!!!!! When I replaced the PBFE (or DBFE something like that) it gave me pickup speed that I had being missing in years. Thats what worked for me.
