Dieselbuilder

I am at my witts end to figger this out, Ip pump is new , fass pump is new , new cam sensor , new iat ........ no codes ........disconnect comp box .....its fine when its cold but once it gets to opperating temp it has a high speed miss. The only thing I can think of is to re flash the ecm........... or a match!!!!! any one with any ideas?

Busboy

Because it's at the exact same spot each time, it's at the exact same place on the TPS/APPS (throttle position sensor/accelerator pedal position sensor) if it's never been changed I would throw a Timbo APPS at it, nothing to lose.

Dieselbuilder

my bad it also has timbos apps????????

Dieselbuilder

its not just at 2100rpm there is were you can notice it the most

torquefan

I don't think there was ever a software update for a miss, so I don't think a reflash will be the answer. Possible injector problem?

Busboy

You could try an infrared digital thermometer on the outlet from each cylinder to look for a cooler one than the others, this might pinpoint a specific cylinder.

Dieselbuilder

Changed out injectors first thing I thought off no luck brand new ones to boot ,and its not just one cylinder it allmost sounds like fuel starvation , not... it has 14psi running at that speed as well you can hear when its running its like the timming changes once in a while I need to scan it next and look at the parramiters of the sencors maybe it will give me a clue I still think its in the ecm?????

SIXSLUG

Does it still do it when you use the cruise control? This is a good test for an APPS failure as the cruise will run smoothly and pinpoint a bad apps.

Dieselbuilder

good idea will try but it might be hard to get the rpm I need to see!

Busboy

With you already having a timbo APPS I don't think I've heard of one of his failing. Do you have a boost gauge. Perhaps the map sensor is not reading enough boost pressure for the ecm when it warms up. If this were the case you would have too much air and not enough fuel but no codes.

SIXSLUG

Pretty curvy roads up there, eh?

Go Canucks!

SLEDGE

Any luck finding the problem? Did you try checking all your grounds and connection point at the fuel pump relay? These trucks are pretty sensitive to bad connections. I am trying to track down a miss myself and that is my next attempt this morrning.

Dieselbuilder

Still looking I still think is in the ecm to may things to do iam going to look at it more on the weekend.......best possible fix a couple gallons of fuel and a match

SLEDGE

I hear ya... Im frustrated too. This morning I cleaned all grounds and reset apps. Still misses. I think you might be on to something with the ecm. I've been wanting a Smarty anyway this seems like a good reason Good luck sir and keep us posted.

SLEDGE

Hey Dieselbuilder, is your pump tapped? This morning I pulled the wire tap and soldered the connection... Truck runs smooth as silk! I figured since I pulled the box a while back that connection wouldn't matter but boy was I wrong. I think it was a combo of the crappy grounds and that tap. I hope this works for you as well as it did me..... Good luck Sir