Engine studder at low RPM's
 

Hello all. I am a new member to this forum, I been reading it for some time now.

Well, I got a problem, so I joined, so I can see if anyone can help.

Here is what I got.

97 F150 XLT 4x4.
4.6l
Towing Package
ABS
Factory anti-theft
Gibson exhaust
K&N Air filter.
About 45k miles.

The problem is when the engine is under load at low rpm's, the engine will studder intermittently. It feels like a lean condition. This has been going on for a couple years now. I suspect a sensor or something is going bad.

Occasionally (2-3 times) when I leave from a stop light, the engine will run rough for 2-5 seconds, like it is missing. Then it will clear up and run fine.

Full throttle response is fine.

Has anyone ran into this problem? Any clues as to what the problem may be?

I called the dealer and described the problem, he said that it is possible that they might not be able to find the problem, and to wait until it gets worse. But I do not want to get stranded somewhere.

Thanks....

I have the same problem you are describing. I have tried several things that have not helped and the dealer has been of no help either. I can't imagine mine getting any worse as sometimes it will miss and shudder so hard it can't recover and dies. Thank god it will start back up and I can continue on but it is real annoying. I'm sure you will get some things to try as there are some very knowledgable people on this board. Just wanted to let you know that your not alone in this frustrating matter.
Mike:mad:

seagasim,

My brother, who works as a mechanic out of his garage seems to feel that one of the sensors is not working correctly, but since he lacks the proper diagnostic equipment to pinpoint which one, he can't help me.

Unfortunately, I am glad I am not the only one who had this problem.

What things have you tried to fix this?

My. '89 4.6 4X4 did the same thing for the first time yesterday. It did straighten out after a bit, today it did it again and the check engine light came on. It seems to be running fine again now, but the light is on. I am open for suggestions too please..
And , how do I reset the light?

I have the same problem too. Mine seems to happen only after sitting at a stop light for 1 minute or longer. I have a 97 4.2L V6 with a 5speed, and it will hesitate for 2-5 seconds after taking off then runs fine. I have changed the plugs, wires and fuel filter and now it does'nt do it as often but it still happens. Maybe cause the weather is cooler its not doing it as much. I have no check engine lite at all. I've seen a couple of posts about this but no one has a solution?

Danny,
I have yet to get any check engine light and the dealer just tells me that I need to wait for it to show. Shoot, I'll be old and grey by then as this has gone on for some time now. I have changed the fuel filter,pvc valve,cleaned the MAF sensor, changed 2 of the 4 o2 sensors, cleaned the throttle body and then I got a new engine because of a blown spark plug and succeding internal damage. With all that said, it still idles like sh*t! I think my next move might be to try the IAC sensor. It's a shame I have to waste hard earned money and be a parts changer in hopes of resolving a problem that the dealer should be able to fix with relative ease. I don't know, maybe someone has the magic answer and fix for us.
Mike

Try cleaning your cam position...
 

sensor located at the front of the head on the driver side of engine..just undo the connection and remove the bolt and pull straight out and wipe the end with a soft cloth ..if it gets to much oil gunk on it ,it wont send a correct signal to the computer.

Sounds like I am not the only one with this problem.

seagasim,

Sounds like you covered the things I was considering. Been thinking that perhaps the plugs or wires would help. But I get the impression that would be a waste of money.

TexfordD,

Are you mentioning this from experience? It does make sense what your saying though, if the "timing" is off, there would be rough idle, sluggish response, and etc.

I see that I will be needing a shop manual for this motor.

What happened to the good old days when cleaning the points with a matchbook would get things going again?

bump..