I just did a lot of work to this truck including taking the plenum off to get to all the injectors, cleaning them and new plenum gasket. It idles perfectly now with no drops and I expect to get most of my original gas mileage back.

But......when I rev it and release the gas pedal, it stumbles....doesn't die, but close. I'm pretty sure I got everything hooked back up. However, it wasn't doing this before. What in the circuit controls idle recovery after acceleration let-off? I know the FSM says the sensors my take 50 starts for the computer to reset everything.

Oh, the stats;'95 V-10, 3500 4WD work truck...original owner.

Kevin

 

IAC motor controls idle. PCM controls it. Did you reset the PCM after doing the work? If you had the battery disconnected while doing it, that will be adequate. Computer should figure out idle fairly quickly though. Almost immediately.... Might give the throttle body a good cleaning, reset the pcm, (again?) then, turn the ignition to on, (not start) count to 10, (don't touch anything) then start the truck. Idle should flare, then settle down to where it should be, according to engine temp.

 

Battery was never disconnected. Which part is the IAC motor control? I probably cleaned it at some point. I did not reset the PCM. Can I take the leads off the battery and touch them together to reset the PCM?

That's what I figured;that the computer should correct the idle up quickly. Throttle body and everything on top got a good cleaning. I'll try your suggestions and write back...thanks!

Kevin

 

IAC motor is just a stepper motor on the side of the throttle body. I *think* its on the firewall side. Should be a four wire connector. (or, it might be on the bottom..... and the TPS might be on the firewall side of the throttle body, don't remember.

Try just resetting the PCM first. Disconnect the negative cable on the battery, turn the headlights on for a few seconds, turn 'em back off, hook the battery back up. I don't like touching the cables together, as that will INSTANTLY discharge everything.... and sometimes, capacitors don't like that.

 

Dude, you be the MAN!!

Held the battery leads together off the battery for a minute. Got in the truck, turned on the ignition and didn't touch anything for ten seconds....started. PERFECT....back to normal. I owe ya big time!

I'm planning on a long trip across country to fetch a car of mine and this is not how I wanted it to start. I figured it was some electronic glitch.

Sorry couldn't wait and rushed out......didn't think about capacitor damage. That's a Mercedes trick for the 124's;touching the battery cables together to reset the ECU.

Kevin

 

Glad it worked. Usually, resetting the computer will solve some rather interesting ills. Makes ya wonder if the software isn't written by Microsoft......

 

Do you still have your '98 2500 V-10? How has the tranny held up over time? They had some trouble with the earlier autos as I remember. I have the 5spd. It was not holding first gear anymore. I've skidded logs with the truck. The transmission people said 'your syncro packs are bad and maybe gears...time to rebuild the NV4500'. WRONG....except for that nut that holds fifth gear on the shaft(finger tight, well documented problem), the tranny was about 95% in great shape. Rebuilt it anyway.

Same problem back, won't hold first gear. NONE of the tranny wizards offered that it might be in the top plate with the springs, ***** and detents....that's what holds your gear choice in place. Top plate no longer available.....you have to go with a different configuration and shifter stalk.

I'm 70 yrs old and I am NOT taking that tranny/transfer case out again. If I had a lift and all that...maybe. So I'm gonna cut a large hole in the floor big enough to get that top plate out. I found a place that seems to know about these top plates and I can rebuild. Winter project. A gentler used truck at a JY with a lower mileage tranny might have a decent top plate. But JY's are like Clinton, if they're talking they're lying. And people have used the NV4500 to build trucks around.....this has depleted available stock.

FSM says it could take 50 starts to completely, satisfactorily reset everything. That's obscene....I second the vote that it's borrowed Microsoft tech. Hard to believe I bought the truck when I was 45yrs old...ha!

Kevin

 

A lot of the stuff that takes a long time to reset, is emissions related. Various monitors require specific drive cycles. As we don't have any form of testing/inspections where I live, I just don't worry about it.

Still have it, and still running/driving good. I had the electronics in the trans replaced in the last year, as it didn't seem to be able to figure out when to shift.... So, fluid/filter/governor stuff/output speed sensor/band adjustment, and it behave a lot better now. Truck has just under 160K miles on it, still original engine/trans. Currently, I have an intermittent rough idle, but, haven't gone digging into it yet. I need some good scanner software to see whats up.... and supposedly, the software I do have "OBDWIZ", is 'one of the best'..... I do not agree. It is extremely limited in what it will show you, mostly just the generic stuff, and not even all of that... you get zero dodge specific data. No misfire counters, etc. Its essentially worthless.

 

Awesome that it's still running well....the tranny. It seems that unlike working on older Mercedes, the tuck is very responsive, even grateful for any work done to it. I only had the CEL come on once in its entire life and that's because I had absolutely neglected it. I can't get the maintenance light off that comes on to tell you the O2 sensors need replaced. I replace the sensors, but the light stays on. The only advice I've gotten short of going to the dealer, is to remove the bulb....lol. The good news is that it's lived its whole life without the cats it came with. Only perk to living this rural is that we don't have to pass emissions. To get the best performance and sound though, I had to have custom exhausts made perfectly balanced with a crossover tube. Finally found a shop with a exhaust flow software program and we went from there.

That ram plenum and all the hardware attached to it to get to the fuel injectors was a real pain. It was running OK, but had a small drop at idle and I knew it could run better. Disappointing on the diagnostic software......should be something better you would think. The V-10 finally gave way to the Cummins iteration. If it started in 1994 and ran until 2003, that's almost ten yrs worth of motor production. I have no idea how many V-10's were made all together.

I have 200K hard work mile on 'er. She was even a pump rig once for wells. It's doing exactly what I thought it would do from the start;the chassis is falling apart around the robust engine & drive train. I was unlucky enough to get a model with the peeling paint syndrome. Having had a GMC truck before this with the exact same issue, I jumped onto their repaint program, but the dealer wouldn't cooperate and the truck never got repainted. I even wrote a letter to Detroit and they declined to paint it as well. They just let the clock run out on the repaint option. I live in a small town and the local painting shops want more money to paint the cab than the truck is worth. I bought it as a chassis cab and put my own work box on it. I'd like to take that box off and put on a nice flat bed with some tool boxes......dunno if that will ever happen because I'm trying to retire.

If you ever find a good scanner program. please let me know. Thanks again for your great help!

Kevin