Engine/Transmission (1998.5 - 2002) heed help with kind of a sudder

[700rmk]

Have we all washed the motor before and got water in the "VOID" areas of the connections, like a humidified distributor of a gasser?



Id pull mine but no spare "VOID" stickers.



If I remember correct it seems to happen more on wet roads, or maybe its those rear wheels spinning

 

[Floor It]

I wonder, could it be the winter blend fuel?

 

[WMann]

Please forgive me in advance Boost for saying this, but I can't say I'm sorry that the new pump didn't fix the stumble problem. I'm fairly sure most of the guys here would ruther it turn out to be a bad sensor or something alot less expensive than a new pump.



Four days ago I installed my new Edge Comp box and I have been sweating bullets over this thread wondering weather or not to install the box for fear of doing harm to the pump. I borrowed a VA box from a friend for two days awhile back and really liked the improvement in performance. Once I got the Comp box in my hand I couldn't stand it any more, it had to go in, pump wire and all. The first time I jumped on the truck in fifth gear from 2000 rpm's, with the box set on level five, fuel on level three, I knew I had made the right decision. I will be wearing a s@%t eating grin from ear to ear for at least a month.



Has anyone tried getting two trucks together, one with the problem and the other without the problem and start switching sensors from the uninfected truck to the sick truck in hopes of finding the problem that way?



In my 93 Mazda RX-7 I had a neutral start switch on the side of the transmission go bad and the car would startbucking something terrible, it would only do it when you were just cruising along and it would only do it when it was hot and muggy outside (raining). Also having the air conditioner on would make the problem alot worse. When it was doing it the ECM didn't know whether the car was in neutral or in gear and I assume the ECM needed to know, one way or the other.



Wayne

 

[JMarkos]

I know there has been someone that said they had changed their IAT senser, with no resolve, but I am thinking that has something to do with it. Driving home the other night in the dark my temp gauge was up to 190ish, and everytime I got into it and built some heat the grid heater would start to cycle or atleast the headlights would flash, I assume that was the heater. I have been trying to get to the dealer for a week or so, too much crap at work, but my dealer thinks that is what is going on.



I was also wondering about the air snorkel on the airbox, is everyone's on or off? I pulled mine off earlier this fall, I think I will put it back on for this weekend and try that, probably won't help but it's worth a try I guess.

 

[Diese1nut]

JM

My snorkle is still on. I have noticed the heater grid cycling more than it should. I think I will try a new crank sensor this week and see if it does ant thing.

 

[Rogue Ram]

I tried to duplicate it...........

... ... . but I couldn't.



I took the truck out and tried to get the rig to do it again, being armed with paper and pen, so I could note RPMS, etc. Of course it wouldn't do it. Soooooo I thought I'd duplicate it; put truck in lower gear, mid RPMS, and back n forth off throttle---kinda like dumping the clutch on your ETH with no throttle. I couldn't get my rig to do the shudder.



It seems my rig has done this when it is "lugging", prior to down shifting... ... ... can one of yall with a 6 spd lug it and make it do the same thing??? I guess I'm just trying to rule out my auto trans... ... ...



I am sitting here DREADING taking this to a dealer..... you know, the ones who ruined my nice paint with a buffing wheel... the ones who don't honor those extended warranties... the ones who stick the WRONG flashes in your 'puter...



Hoping..... praying... .



Rogue

 

[Boost]

I just reread all the pages in this tread and someone asked if maybe vibration or harmonics might be causing this. I might start rambling as I'm just thinking aloud... but I remember when I installed my fuel pressure guage. I installed the sender right on the pump at first and the guage would work normally most of the time, but at midrange throttle --excatly the same time mine engine starts bucking-- my fp guage needle would start dancing all over the place. I thought that my lift pump was turning on and off rapidly. I then mounted the sender remotely and the guage works perfectly all the time now. So maybe the harmonics are causing some other sensor to temporarly freak out and send a signal to the vp44 to cut back fuel. If this was the problem it seems very hard to fix. Problably not possible to "remote mount' any sensors. Any thoughts?

 

[WMann]

Since you have a new pump, I think its safe to say that there's nothing wrong with it. If there isn't anything wrong with the pump, then I think its safe to say that the pump isn't going to do anything its not told to do. Since the computer is ultimately in control of the injection pump, I would like to know if anyone has tried switching out computers with a healthy truck? Are the computers in these trucks easily accessible?



Someone mentioned the grid heater. I have noticed in my 2001. 5 that when the engine temp has been up for awhile and the outside temp is in the mid 30's, if I stop somewhere for just five minutes, then get back in the truck, the grid heater will cycle for five miles or so. I think that is rather strange. Has anyone tried pulling the fuse on the grid heater once the truck is up to temp to see if that would have any effect? Since the grid heater is basically a dead short, it could be placing too much of a load on the electrical system a causing a problem. It might be worth while to check all of the ground straps pertaining the computer and the engine ground straps. I guess it wouldn't hurt to clean the battery cables also.



Wayne

 

[Okie-Go]

Got back from a 4 hour trip Sunday afternoon. Truck still did it and the temp was 60 degrees. (I'm getting nervous. ) I can't afford to get a new truck but this is bugging the big dog out of me.

 

[Fireman Dave]

Mine is fine - for now.

Mine stopped doing it now. Of course, right before I take it in. I think the APPS is definitely the suspect - maybe it was a little dirty/sticky when it was doing it, then it cleared up on it's own.

 

[Rogue Ram]

....same here....

..... now I can't get mine to do it again either, but I had to cancel my dealer trip till next week. Maybe it'll happen again.



We paid HOW much for these trucks to get these kinds of problems?



RR

 

[Okie-Go]

Where is this apps thing located at. Does anyone have an idea how much they cost and/or how hard to change out?

 

[Diese1nut]

APPS

The APPS is under the plastic cover above the injector pump. Easy to replace but $320. +/- Hope this helps.

 

[Ram4Sam]

Rogue Ram

"It seems my rig has done this when it is "lugging", prior to down shifting... ... ... can one of yall with a 6 spd lug it and make it do the same thing??? I guess I'm just trying to rule out my auto trans... ... ... "



Rogue, I actually did this and went through the symptoms mentioned in this post, but not intentionly. Last summer while towing my 5er, I was on a divided hwy, going around 35 mph, just cruising along. I was in a gear higher than I should have been and just about to downshift. I was almost through an intersection when out of the corner of my eye I saw some goober was going to run the stop sign. I figured he was going to hit my trailer, so without downshifting to a lower gear, I punched it and he missed me. But this lugged my truck real bad, it started to miss, buck, lit the check engine light and went into limp mode( no power). I shut it off, checked all my box connections and refired it and it ran fine, but the light stayed lit for a day or so. It ran fine for the next few days but then started to miss at midrange throttle settings. (but no check engine light) I got an appointment at my dealer for the next day as I keyed out code P0237-low MAP sensor voltage. When I removed my DDTTM, miss was gone but trip to my dealer is only a few miles so I don't know if the box has any relation to the problem. Anyway, dealer diagostics showed MAP sensor putting out low and erratic voltage. They replaced the Map sensor and it has been fine ever since. (approx 5000 miles, 4 months)



Sam

 

[Boost]

Temps around here have been 0-30*F and mine was bucking very bad. Yesterday my overhead comp. said 55* and I could just barely get it to do it. Like other people who have posted, I to think this is temp. sensitive. Bad thing is it might not get that warm again for 3-4 months. BTW I was quoted $372 for the APPS today. I would hate to spend $372 if it did not help, but would happily do it if it would. Anyone tried the APPS yet ?

 

[Fireman Dave]

boost:



I'm taking mine in on Thursday, but it isn't doing it now, so who knows if they'll be able to solve it. I'll update on Thursday.

 

[OILBRNR]

My '99 does this too. Noticed it after putting in an EZ. Only does it in the 1800 RPM range under load, like going up a significant grade while trying to accelerate.



This started happening this past summer here in AZ, so I don't think it is temp related.

 

[JHansen]

I'm such a dolt....

I've been following this thread for a while-mine does shudder as well only at certain load points and throttle openings. Never really did it until the EZ was installed... . I just assumed it had something to do with the programming in the EZ and put it off to the side for a future project.



Since this thread has been going I've been racking my brain trying to think how I can help. Finally it hit me (here comes the dolt part )-I have the ISB Light Duty Fuel System Troubleshooting and Repair Manual sitting right here by my side!! What a freakin' idiot!



A lot of what it has to say doesn't much help without INSITE or something similar-but it does have diagnostic trees that may help us pinpoint the problem.



Better late than never I guess-so who wants to know what?



Jason

 

[Diese1nut]

Shudder

JHansen

So what does it say about these symptoms. Mabey APPS or injector pump or another sensor.

 

[JHansen]

Nothing really about shudder-closest thing to it is "Engine Speed Surges Under Load or in Operating Range". Following is the list of their diagnostics:



-Fuel level low in tank

-Electronic fault codes active or high counts of inactive fault codes

-Fuel filter is plugged

-ECM calibration is outdated

-ECM is not calibrated or has incorrect calibration

-Accelerator pedal restricted or malfunctioning

-Engine Speed Sensor or circuit is malfunctioning

-Moisture in wiring harness connections

-Air in the fuel system

-Fuel lift pump is malfunctioning

-Fuel injection pump voltage supply circuit is malfunctioning

-Fuel inlet restriction

-Injector is malfunctioning

-Injectors are not correct

-Injector shim thickness is not correct

-Fuel connector is leaking fuel

-Vehicle parasitic losses are excessive

-Clutch is malfunctioning or not correct

-Fuel drain line restriction

-Fuel grade is not correct or fuel quality is poor

-Turbocharger is not correct

-Turbocharger wastegate is malfunctioning

-Turbocharger wheel clearance is out of spec

-Fuel injection pump is malfunctioning

-Internal engine damage



Obviously some of these are pretty simple to check out. For example on my truck I can tell you for a fact that the lift pump is working because I run a FP gauge. As to the injectors not being correct, I guess I'm guilty of that with my 275's... . and the EZ could fall under the category of improperly calibrated ECM . The things I see on here that interest me are ESS failure, APPS failure, water in the connections, VP44 voltage supply, and fuel drain line restriction... . especially the last 2. These haven't really been discussed yet...



So what specifics on any of the above can I add?



Jason