Hesitation/bucking-help?

[Vaughn MacKenzie]

Don't get your hopes us

Originally posted by MPagnucco

I hear what you guys are saying. Like Rubberneck said I wish something would just break so we could figure out what it is.

Mine has not been smooth since day one, and now I'm closing in on 57,000 miles It gradually gets worse but I have been waiting for months for something to TU so then I can replace the faulty culprit and be done with it!



My truck:

--when new it idled rough

--by 40k it was surging on the highway

--around 50k I noticed some days it is very rough under power above 2400rpm. Then the next day it is smooth



Evan Beck who works at the Power Shop has replaced a few VP44s listened to my truck today. He's pretty sure the only fix is a VP44 replacement . I too have been to the dealer 2-3 times but it's like pulling teeth to make anything happen. They reflashed it, had no effect.



I agree with you guys electronics have a very big downside. While they are great to react to input signals and control injection precisely, all it takes is a bad sensor or electrical noise to foul things up. With mechanical injection the only thing telling the engine how to inject fuel is the throttle rack & AFC. Good hard mechanical control.



Another tought on the D/C electronics, it seems clear to me there has to be a pretty significant fault condition before an code is generated. If the ECM recored faults as it should, imagine all the dealer visits D/C would have to deal with



Vaughn

 

[jimnance]

I never had a surge problem with my truck until the first time I pulled a load after installing the EZ. If there was a surge before it was undetectable by me. Now, when I'm pulling any kind of a load (today it was a 2,000 LB boat/trailer) I get the surge when I'm mid-range cruising. If I let off a little it goes away, and if I get in it it goes away. With my big fifth wheel (20,000 lbs truck & trailer combined) it is the same symptoms but more pronounced.



I really wonder if it is a problem in the EZ that somehow introduces a fault elsewhere in the electronics that doesn't go away even after the EZ has been disconected?

 

[RAPID RICK]

buck-n-jerk

anybody figured out what the h#ll the problem is? I put a new TPS (apps) on & it helped a little. Had the reflash done & it did nothing. Had a new lift pump put on yesterday (warranty) & went for a test drive & GUESS WHAT---- my damn clutch took a dump.



Summit

A friend of mine has a 2002 3500 & it did just exactly like yours. Run---stop---run----stop----throttle back to idle for a few seconds & it runs again---sort of--- Hope somebody finds a cure for this crap soon.

Rick

 

[rubberneck]

Read the post Marco ( the man behind the mad ecm) wrote earlier about coolant temp sensor voltage. makes perfect sense

 

[tmacc]

We recently had some of that weird winter weather where it went into the 70s for several days and the hesitation went away. Seems to point to a sensor of some kind.

 

[CUMINNTSTRKN]

guys



my new 02 does the same thing. at about 1800-2000rpm under light accell it stumbles a bit. i will try the coolant sensor.



jim

 

[sdalton]

I had the ecm reprogramed for the TST that was out on this. I have had no problems since. Almost 2000 miles since the reprogramming. I used to have the hessitation one or twice a week, and it even started to do it while at idle.

 

[tmacc]

sdalton,

Would you post the TSB re-flash #?

Thanks.

 

[rubberneck]

I have had my truck reflashed with the latest/greatest software, no help. I am going to pull the wiring harness off the ecm and pump, and make sure all pins are making good connections. if all connections good, i will look further. All of my sensors apear to be within spec. i may just replace the coolant sensor anyway (what the heck im in to this thing eyeball deep anyway. )