rough idle

290 Acar · #1 Tue, September 11th, 2012, 07:25 AM

Hi everyone! I have an idle issue with my 02 Ex with a 7.3. It runs okay cold but, when it gets warmed up it really idles choppy. On the scanner it varies around a 120 rpm or so. When you pull out it goes smooth as can be with no smoke or hiccups. As you roll off the throttle just part way to run along, it becomes very touchy from off to on in as much as it slaps the driveline slop around. The truck has rosewood stage ones, driven reg return, gutted pedestal with difuser plug on the harness, different compressor housing, 6673 filter, full 4" MBRP, ccv mod and CTS with Bills tunes. Also had the pass side head off for other reasons and did a new gasket. The icp,ipr,uvchs,and glows are all new also.

The only codes are the intake air heater as it is disconnected and the KAM. I had the truck together and running long before I had tunes for it and this problem was there then, so i don't think it is a tune issue.

I must say that it runs great when your on it and the tunes really made a difference in how it acts all the way around. I just can't figure whats wrong, even with a scanner on it. Anyone have an idea?

rammertide07 · #2 Tue, September 11th, 2012, 01:03 PM

Try disconnectiong the icp and see how it idles.

Can you read icp and IPR duty cyclye?

290 Acar · #3 Tue, September 11th, 2012, 05:59 PM

I haven't disconnected the icp since Friday when I changed the ipr, then the icp, with new Ford parts. After that I ran it 20 min home and it acted the same.

I threw the scanner on it and got these numbers at idle.

icp-475 to 480 psi
icp duty cycle-10%
icp volts-.75 to .83
ipr duty cycle-11%
eot-187
map-14.4
fpw-1.7 to 2.2

Probably TMI, but that's what I looked at. I'm just surprised at how well it runs when you put the boots to it, but when you jump out or stop, it is cranky. Thanks!

rammertide07 · #4 Wed, September 12th, 2012, 08:34 AM

What type of scanner are you using? ICP DC is the same as IPR DC on most scanners I've seen. But they are probably using the same PID. ICP is a little low. I'm having kind of having the same issue. Mine stumbles when I lightly accelerate, mainly after it first starts up. But runs smooth when I get on it... especially with this cool fall air coming in. I'm kinda stumped right now with mine. I'm thinking the IPR or ICP....leaning more toward the IPR though. There's a part of the IPR, screen....filter???, that can cause it not to close all the way if it gunked up.

290 Acar · #5 Wed, September 12th, 2012, 12:57 PM

The scanner here at work is a Matco Determinator which is basically an OTC Genisys product. I had run the scanner on the Ex before i started all this work to check the HPOP health. Since it came out great i did not change the pump which has about a 140 thou on it.

The icp seemed low to me also, but I thought I saw on Dieselman's page where he listed idle pressures of 400 to 500 psi?

Thanks