Engine/Transmission (1998.5 - 2002) thoughts on shuddering

[Huff N Puff]

Lots of years in the bussiness,it sounds to me

Like the clutch can't handle the load,horsepower combination,if you have a two piece driveshaft a ujoint or center support could be causing the shudder also. Merv

 

[2-ND TIME]

engine shuddering

Please everyone that reads this answer my posting and maybe we can figure this out?????????????????? I THINK THAT I HAVE FIGURED OUT WHAT IS GOING WRONG???? I just wasted over $1300. 00 at chrysler dealer for them to till me that they couldn't find what was wrong they did check some of what I asked them to check. WHAT I BELIEVE IS GOING WRONG WITH THESE IS THE FUEL SOLINOD. THIS ADVANCES THE INJECTION TIMING OF THE FUEL AND EITHER IT OSOCILATES FROM A BAD SIGNAL OR CROSSED SIGNAL OR THEY DON'T PUSH THE FUEL ADVANCE FAR ENOUGH TO GET THE FUEL IN EARLY ENOUGH??????? With mine they did change the valve settings and find out that some were 0. 010 out of spec, It is funny that I could tel lthat the valves were out I even commented this to one of the mechs when he was giving me auto pilot to try to see if this would work he had no answer for me. O'yes that one was the one who change the fuel filter at 2 lbs across the filter. It is funny the place that did the valves swore that it was alright to be adjusted hot yes this was at a dodge crys-slerrslip for they even managed to find that the lift pump was not working in 5 seconds. That gave me 35 rwhp more, amazing when you go from 130 to 175 what difference it makes. STILL driving to work and driving down about a 5 to 7 %grade had bucking at 80 to 90 KMH. This is pathetic. The service advisor told me today that the diesel tech only got paied for the vehicles that he fixed and didn't want me to bother him. The other day reading on the vp-44 pump several things don't make any sense to me. That when you are goine down hill with the engine holding you back that all the fuel is returned to the tank. I believe to false. One the engine never cuts out and depressing the throttle from 1/8" to 3/8 "is enough to increast the rpm. I think that there is only a few hundred rpm difference at most of fuel delivery???

 

[aviatorman]

Shuddering

Got a few years with fuel injection , and it occurs to me that you're boosting manifold pressure above factory standard. Normally not a big deal, , except when you're not positive about the flow rates on each individual injector nozzle. Hence, , when the boost starts to really crank up,,, it only takes one lazy injector to spill your coffee , , or put a buzz in the drive line. Most common error changing injectors is to use a "dirty " removal tool. The smallest particle will interrupt the flow just enough to cause the symptom. Just a thought for you to ponder, ,

 

[fj40charles]

Aviatorman,



Interesting. Are you saying there is a possibility of all these people having shuddering problems are related to a bad injector?

I guess it could make sense since it happens more when the weather is cold making the fuel thicker...



Charles

 

[favord]

Aviatorman, I like it. Seemed like the shudder became more pronounced after installation of the Bully Dog II's... I believe it was there with just the EZ also. My average boost under load with just the EZ was probably 24-26, with the injectors average under load is probably 26-30# which is right where the shudder begins and persists. How would I explain that it seems to go away when I get boost above 30# and keep the throttle pegged (it's fun to drive that way but not practical with horses in tow)



If it is a bad injector how does one track that down? Thanks for thinking about this - gotta be a reason for it.



I was wondering if it was something faulty in the boost module portion of the EZ and wondered about piggybacking a different boost module into the works and leaving EZ for fueling/timing... ?? Is that possible?



Doug Favor

 

[favord]

2nd time - not sure we're talking the same problem or not. I don't get the shudder going downhill when the engine is off load. I've noticed that when I crest the top of a hill with boost over 30# as the load on the engine decreases and boost decreases it will buck as it passes through the 26-30# range then smooth out.

 

[Gary - K7GLD]

After reading observations in this thread, I've developed my own theory as to the cause...



The computers in these rigs have very extensive and detailed operational "mapping" of timing/fuel delivery vs a large number of external control factors - engine temp, road speed, boost pressure, etc. , etc.



All these factors are used by the available programming of the computer in determining fuel timing and delivery in NORMAL operation and circumstance, with reasonable "overhead" to allow for at least a small percentage of edge-of-map operation.



BUT, in a few isolated circumstances, and due to minor variations in specific vehicles and assembled components, if additional power enhancment not designed into the existing fuel timing/flow map are encountered, it puts operating parameters "off-the map". and puts the computer into the same sort of confused condition we sometimes see in automatic transmission when they are put under a borderline situation that forces them to "hunt" up and down in gears, seeking the best ratio...



That's my theory, and I'm sticking with it...

 

[Summit]

not the inj.

dfavor1, it's not the injectors on mine. took'em out & back to bully dog and they pop tested them right there and all were perfect. when re-installed, put in new injector tubes, as we thought that maybe i had a partially plugged tube that was starving 1-2 injectors for fuel and that was causing the bucking. but as ALL the other things i've tried so far, it's not the prob.



it's not air in the fuel either, ran a clear hose on windshield for 2 1/2 weeks inbetween filter and inj. pump.



my truck will buckas soon as it's placed under load, does'nt matter what the boost is10 or 30 and inbetween. it just surges while cruising.



does anybody else use a mechanical fuel pressure guage?

 

[dtempleton]

I've got on 01 w/auto. I noticed on mine it started to surge or buck a little when it was in overdrive, about 40mph. I had let the truck idle for about 15 min. before taking off. I also noticed this problem in warm weather also. About 2 months ago I had a program put into the ecm and installed a set of 275hpRV injectors. That magnified my problem. It's not real bad yet but it's there. We got some nasty weather the other night and I had to use 4wd to get to work. I was running about 55mph and under light throttle it started the surge or buck again. First time I noticed it at that speed. Doesn't do it in 2wd. It must be when a certain load is put on it that it does this. Can seem to throttle out of it. Don't notice it at low speed when warmed up. But on the highway it was warmed up. I guess I'm trying to say is that mine started doing it when it was stock. The upgrades magnified the problem. I thought maybe I had an inj. pump problem. But now I'm not sure. Might put one on anyway. Let DC pay the bill. I was wanting to install a comp and stage3 inj. , but now I'm afraid I'll make the problem worse. If anyone has a solution I'll try it. Dan

 

[2-ND TIME]

engine shudder

Read the replys and have to add that . I asked for the mechanic to test the injectors for spray pattern , and pop test them, and the balance test for them. They did a infared test on them and found that they tested to 10*C difference and didn't think that the rest of my testing was nessecary??????????????Did they find the problem NO as usual??? NO mine is low on power ? and bucks at light throttle and when you are climing a hill making it work. SINCE NEW YET ????? With the valves adjusted the problem is worse ALOT. Please read the article on the pump on the web this should inform one of the soliond valves job to adjust the timing of the fuel injection for this is criticle to the cycle of the power cycle.

 

[Summit]

Re: engine shudder

. Please read the article on the pump on the web this should inform one of the soliond valves job to adjust the timing of the fuel injection for this is criticle to the cycle of the power cycle. [/B][/QUOTE]





?,,,???. . ???. Sorry, deaf in that ear, need to explain better or i need a translator?



one of jerry's kids