Engine/Transmission (1998.5 - 2002) surging

[spratt]

I am a new member and hope someone can steer me in the right direction. My truck has started surging at cruise. The tack will jump up a bit and it feels like the engine revs a bit. It seems to do it more when little throttle is applied rather than when under power. It does it with the cruise control on or offand with od on or off.

It is a 2000 with a original VA box that I have removed[ with no change] and 275 hp injectors.

it has a new lift and injection pump. The fuel filter has only been in for 10000 km.

Can anybody give me some ideas, I am supposed to leave on vacation in a week so need to act fast.

Thanks in advance.

 

[Midnite]

Sounds like the torque converter may be unlocking and locking when it shouldn't. I may be wrong, but I thought I read something about RF interference on the circuit that controls the lock/unlock and that DTT (and maybe others) have come up with a filter that you can wire into it.

I have an NV4500 in my truck though, so hopefully someone with firsthand knowledge about this will chime in soon.

Mike

 

[hsmith]

Are there any codes??

 

[monkeyman]

Try your speed sensor if your truck has it on tail end of over drive housing. You did not mention if it was an auto or manual. The speed sensor does not throw codes, can mimic Fuel injection pump, bad fuel etc. I am on my second one. Takes about three minutes to change, and Auto Zone has them cheap with life time guaranty
Rick

 

[spratt]

Thanks for the replys. My truck has an automatic with posi The only code I get is P1693 which has been showing off and on for a few years.

Is the speed sensor located on the top of the rear end housing?

Can anybody tell me where I can buy the filter and instructions referred to by Midnite.

Thanks again for steering me in the right direction on this issue.

 

[Midnite]

DTT has contact info on their website, DTT Performance Diesel Transmission and Power Accessories.

Mike

 

[spratt]

Problem solved. I went to the dealer as we do not have Auto Zone stores in Canada and got a transmission speed sensor and voila, running perfect. The old sensor was covered in metal filings and metallic mung.

Thanks to all especially Monkeyman.

if you are ever in Canada [Windsor Ont. ] I would buy you a beer.

 

[spratt]

Spoke too soon. Surging came back. I guess i did not go on enough of a test drive after installing the transmission sensor.

I went to the DTT web site and read the info on the filter. I started checking reconnecting and cleaning various grounds. I drove about 100 km. this am. and no surging. Knock on wood, problem solved.

Thanks also to Midnite.

 

[monkeyman]

Yes, speed sensor goes bad, but AutoZone has life time waranty ,Keep old one and return in about six months for a spare, its the American way!
Rick

 

[spratt]

Same symptoms are occuring again.

I think I have traced it to the connections at the PCM on the firewall. Before, when I was checking grounds I also wiggled the 3 plugs on the PCM. Each time the truck would run good for a while then start acting up again. If I can figure out how to remove the plugs I will clean and grease the pins. Can anyone please tell me how to remove the plugs. Tonite I stopped the truck while it was surging, wiggled the plugs and the problem disappeared. I read in the shop manual that the PCM controls, among other things transmission converter function. I think I am onto something and it looks like other owners who have this problem may benefit from checking these connections as well as the grounds. I hope this solves the problem. I cant stand it when the truck does not run right.