WHAT IS THIS?

[Brunner88]

Having trouble with something and I suspect this thing. Is this in communication with the fuel pedal? I get a bouncing throttle and a really fast miss...or hiccup.....at times. It only happens when it warms up. From a cold start it never does it. Once it warms it does it. When it does it if I press the pedal more it stops. If I let off the pedal it stops. It doesn't always do it but when it does doing either thing eliminates whatever is going on. I've tried a different fuel pedal thinking it was the potentiometer...much to no avail. Same thing was happening with the new pedal. What is the feul pedal sending a signal to and where is it located? I believe that item is the problem.

[rangerstx]

that is the boost controler. it works on a duty cycle commanded by the pcm and the input from the pcm is the map and ebp sensor. unless your problem is boost related this is not causing it.

i would suspect the icp sensor for your problem. when it acts up unplug it and see if the idle evens out. if it does the icp sensor is not reading correctly

[ken6881]

Originally Posted by rangerstx

that is the boost controler. it works on a duty cycle commanded by the pcm and the input from the pcm is the map and ebp sensor. unless your problem is boost related this is not causing it.

i would suspect the icp sensor for your problem. when it acts up unplug it and see if the idle evens out. if it does the icp sensor is not reading correctly

I agree.

If its doing it at idle the waste gate solenoid is not doing it. I would check icp as stated above.

[Brunner88]

Here is what it does.
At idle ...I will once in a while get a bouncing idle. The rpm won't vary by more than a few hundred rpms. You have to actually be listening for it to notice.

It can do the ugly part at several speeds.

The bad part is when driving. It will jerk really fast. Or have a super fast hiccup. A few of them. I push the gas..it goes away. I let off it goes away. It does not do this all the time. It does this certain times. Aside from a very feint and infrequent bouncing idle, the idle doesn't do anything. Most of the time the idle doesn't bounce.

The other thing I've learned to live with but it is just annoying know it is there and can do it.

[catlinB]

Any fuel leaks ? My 96 would do thus cause the mechanical pump was weeping fuel.


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[Brunner88]

No there are no fuel leaks. No engine lights on. No computer program. Nothing but a stock excursion. 2001. The jerk or bucking action is lightning fast. As I said I can make this go away. Press the go pedal more or let off. It doesn't always do this and it never does it from a cold start. Only when the engine reaches a warm operating temp is when it might start.

[ken6881]

i would drop a $50 icp in it and would bet your problem goes away.

[Brunner88]

Originally Posted by ken6881

i would drop a $50 icp in it and would bet your problem goes away.

Two things, would a bad ICP NOT throw a light on? Moreover where is this located.
I have a standard scan tool and it is coming up all proper like. No codes etc.
What would some of the readings be on one of those million dollar computers if this was bad?

I might have access to one of those comps but I don't know what is good or bad with the ICP.

[Codum]

Originally Posted by ken6881

i would drop a $50 icp in it and would bet your problem goes away.

Where do you get a $50 icp and is it any good? I just picked one up from napa, had to talk them down to $150, they wanted $175.00. Thanks!

[rangerstx]

With this symptom i doubt I will show any codes. My last 7.3 that I had was doing this. The only way I could catch it doing it was by looking at Icp pid graphed on ids.