Hello all. I have been browsing the forum for a while and would like to thank everyone for the wealth of information available. My problem is a loping idle (500-900rpm) on first start. It goes away the instant I push the accelerator the smallest amount. Then it purrs. After I let it run a few minutes it will not do the lope again on starting.

The back story. 2000 F350 with 223000 on the truck but it has a reman in it and I don't know the history. It was not well maintained. I picked it up cheap because it barely ran. Had it diagnosed and came up with: bad fuel pump, clogged tank filters and bad injectors.

I just finished putting in swamps remans, new fuel pump, hutch mod and pre pump filter, rebuilt fuel bowl, riffraff frx, international up pipes, new exhaust, pedestal orings, uvch's, and Ford AIS, new oil and filter.

I've put 500 miles on it since the injectors. Like I said after I tap the accelerator it runs great. I unplugged the ebpv after reading another posts and that didn't change anything. Also checked the hpop reservoir before starting this morning and it was full. I'm going to rebuild the IPR later today.

I don't have AE but just got the Torque app and have an elm327 coming tomorrow.

This is my first powerstroke, I was previously a 5.9 guy.

Any ideas/help is greatly appreciated!

Sorry for the long post.

 

Update: I tried starting after cleaning/rebuilding the IPR with no change. I tried starting it in neutral after reading another thread with no change. Checked the ICP sensor and there is some oil in it. ICP when started jumps from 500ish to 1200ish as it lopes. Once I tap the accelerator and smooth out the idle ICP drops to 500ish and holds steady. Once I warmed it up a little on starting ICP spikes to 1200ish until it starts then steadies to 500. During driving ICP appears normal based on what I have read in the Torque threads. I'm having trouble with the IPR duty cycle. Probably the cheap knock off OBD sensor I'm using. Not sure where to go form here. Truck runs great besides the first start so I guess I'll wait for whatever is causing it to get worse or go away.

 

Remove the wiring harness from the ICP sensor and start it. See if that makes a difference. What kind of problem are you having with IPR duty cycle?

 

Tried starting with the ICP sensor unplugged. It would barely idle with the RPM jumping between 400 to 800. It was almost stalling on the low end. I pushed the accelerator about half way down before it even attempted to rev up. Plugged the ICP back in and it was back to the 500 to 1000 RPM lope smoothing out as soon as I pushed the pedal.

I'm having communication issues between Torque Pro and my OBD sensor. I guess my truck doesn't like the cheap sensor. It will talk sometimes but then stop.

 

I'm going to guess you have a problem with the IPR. There are other things it could be, but based on the symptoms, the IPR seems most likely to me. It sounds like it isn't reacting to commands from the PCM as quickly as it should, so the the PCM tries to compensate by increasing and decreasing the duty cycle. It would be very helpful to have the actual OBD data, though. I have a cheap adapter that hasn't given me a bit of trouble. I bought this one from Amazon: and I just noticed the price has dropped by 4 bucks since I bought mine, too.

 

when I ran 15w-40 oil mine did the lope thing. Since shifting to 5w-40 I have no lope.

 

Pikachu that is the exact sensor I have, but from a different seller. I will keep messing with it today to see if I have a setting wrong. I think I have it set up right however.

I've read about 15w-40 causing the lope. My question is switching to 5w-40 actually fixing the problem or treating the symptom? Since the truck was designed for 15w-40? I haven't read everything on the new oils. Is the theory that in making the new oils for the new diesel trucks did they somehow create an oil some of our trucks don't accept? Switching oil will probably be the first thing I try. It doesn't hurt to have fresh oil and it's a lot cheaper.

What brand IPR? The local store has BWD for 180. Or they can get motorcraft for 280.

 

http://www.riffraffdiesel.com/ipr-in...gulator-96-03/

It doesn't specifically say on the mobile page but everything else they sell is Motorcraft so I would assume this is as well.

 

I can connect to the OBD sensor just fine but Torque Pro says that it can't talk to the ECU. If I connect and disconnect enough times it will talk to the ECU but then it won't start while connected. I tried it on my wife's car and it works just fine.

If I hold the idle at 1000 for 10-20 seconds then let off RPM will drop down to 500 then slowly(3-5 sec) work back to 700ish. Don't know if that is normal or not.

 

Switched oil over to Mobile 1 5W-40 TDT including HPOP. First few starts it still loped but not long. This morning it loped once and started idling normal. I think the IPR sensor is on the way out but the synthetic will probable help for now. I'm going to be out of town for a while and the truck won't be driven much for the next 6 months so I'll just wait to do the IPR. I'll probably get AE also so I can make sure I'm not missing anything.

So far my truck likes the synthetic. Injector sound is even more smooth.

Thanks for the help! I'm sure I will be seeking more advice in the future.