Hello,

I have a 01 cummins auto, only mods are 75Hp injectors, and a fass. I just had a new injection pump installed, however the problem was there before this. When the truck is put into gear from P or N, it stalls. It will fire right back up, and when you get it to stay running, it acts as if it's under a load. When put back into park from Drive or reverse if it stays running, the RPM's jump up as if I tapped the throttle. Anyone know what this could be? Thanks in advance!

Could be torque converter is staying locked. I have the same problem. Haven't officially diagnosed whether it's the TC itself or the electronics in the valve body. Check for codes..Does it do this all the time or when cold or warm? Stock tranny?

Is this a new to you truck? A good tight converter will chug the truck down or stall it out if it's idled just a little low.

Yes, it is a new to me truck. It seems to get worse once it's warmed up. I did notice, that once it's stalled and I put it into N and re start it, if I put it down to 1 real fast rather than Drive it will go ahead and take off.

Im guessing torque convertor clutch is engaged. To test to see if its good, you put the pickup in gear, hold the brakes, and with the drb you activate the torque convertor clutch. If it works right, the truck will load up and die

Is this a new to you truck? A good tight converter will chug the truck down or stall it out if it's idled just a little low.

This ^^^^

Sounds like your torque converter isn't unlocking like it should. Mine would do that same thing if I left the torque converter lock up switch on. Has it always done this since you owned it?

Mine did this a few times after some hill climbing and heavy load. I kept starting it in neutral then let the truck coast downhill for a little bit and then clicked in either forward or reverse depending on the direction of the slope. After about 4 -5 times it stopped misbehaving.

 

Knowing the cost of a rebuilt trans and having to deal with many rebuilders that aren't the best around I have come to the conclusion that changing the trans fluid every 15,000 miles, but no power flushes Is the best savings on the planet. Just drain out what you can and replace. Do the filter every other 30,000 miles.

Edited January 4, 201510 yr by JAG1

It's showing TCC Solenoid is off at all times. Going to replace the solenoid and see if that fixes it.

If it's showing that the TCC is off then you could have a short in the wire causing it to be grounded out. Did you look for any toggle switches? The previous owner could have installed a torque converter lock up switch. I have a lock up switch on mine.

It does actually, spoke with the previola owner he stated it was a smone switch.

Is this a new to you truck? A good tight converter will chug the truck down or stall it out if it's idled just a little low.

 

Set the idle higher than stock and it could help? Any downside to this? Mine stalls out with my new triple disc when put into gear as well

It does actually, spoke with the previola owner he stated it was a smone switch.

 

If that isn't it, I just spoke with Phil Taylor at DPC (diesel performance converters), he said that a lower stall converter and a tight converter can stall your engine out. His recommendation is a stock stall, but sounds like your problem might go deeper than that.

Set the idle higher than stock and it could help?

You could do this with a 12 valve, but a VP or CR you can't set the idle. Mine idles at about 900RPM so that it will be 750RPM in gear.

I see the hard anodizing flake off of the switching valves in the valve body quite often. The flakes can (and often do) stick the switching valve in the partially applied position. This will cause the converter clutch to drag. Sonnax makes a decent replacement valve if there is any flaking/jamming going on.

 

Even if the TCC solenoid is stuck in the on position, there isn't any fluid being fed to it until after the 1-2 shift (unless someone has modified the VB for 1st gear lockup), so it would not be possible for it to cause a lockup in 1st or reverse.

 

One note on low stall converters; a properly built low-stall converter will require little (if any) more brake than stock to hold the truck stationary in gear at idle. If the converter is pulling the idle down so far that it kills the engine, it's too tight...

The stator clutches can seize hard to the point there is no stall in the TC and as soon as a gear engages the engine dies, or, they can partially fail and pull rpms under the set point and try to drive thru the brakes.

I would put the truck in neutral and drop it into drive and immediately let off the brake. May even have to give it a little throttle to overcome the dragging TC. The Fuel system on the VP44 trucks can not compensate fast enough to stay running when put under a load at idle and will easily stall. If the truck takes off and drives fine I'd say you have a failed torque convertor. If the engine runs fine and there are no codes that point to something else it is almost definitely trans related. There is nothing on the engine side that will cut the fuel simply by putting it in gear.

Edited January 4, 201510 yr by diesel4life

While there is really no such thing as "stator clutches" in a torque converter (unless you're referring to the stator's roller clutch, which is supposed to be locked and holding the stator stationary when under load), the converter clutch plates themselves can be held partially applied, causing a mechanical coupling between the impeller and the turbine. This will drag the idle speed down and, in extreme cases, kill the engine at a stop. There are several causes for this, the most common of which (that I see) is a sticking switching valve in the VB. A failing clutch can also cause this when friction material that is peeling off of the friction plate(s) becomes lodged in the clutch assembly, causing a dragging clutch and can kill the engine as well.

 

At any rate, the test given by diesel4life above will help to isolate where the cause may lie.