biggest 7.3 lemon ever
- Thread starter The Dude
- Start date
twt
Full Access Member
I just spoke with Bob @ diesel site & he said to try unplugging the icp & drive, or disconnect batterys for 30 min. Either way these are 2 cheep things to try.
BJS
Full Access Member
I just want to chime in , because my truck has a almost miss also. what is the IPR & what dose it do? My truck seems to do this at low boost 1- 4 psi. I have been looking for this for a while.
the IPR is on the HPOP on the bottom of the back side offset to the driver's side.
The IPR is essentially a blow off valve for the High pressure oil but it is electronically operated instead of a simple calibrated spring. The IPR is controlled by the PCM primarily based on input from the ICP. The IPR controls how much of the output from the HPOP goes to the heads to maintain needed pressure and how much goes back to the oil pan.
Hope that helps some
Rebuilt IPRs are simply cleaned with new o-rings, they are very delicate and easy to damage when you take them apart to clean. for the patient you can clean them with a bit of brake cleaner in the holes.
The Dude
Full Access Member
I`m going to check my oil psi tommorow! I`ll get a gauge made up! I`ve already disconected the icp and drove it made no difference and I disconected the battery`s! It`s getting worse as the days go on! I know I shouldin`t be driving it but I need it and I want to try and avoid the stealership!!!! thanx guys for all the advice!!
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melmount
Full Access Member
can you get to the ipr without removing a bunch of stuff? The sensor is on top(sort of) on drivers side cylinder head right?
melmount
Full Access Member
The ipr, is that mainly for starting pressures? the 500 psi? Does it effect the truck when its running too? If its stuck open? It would hard start right? Also lose high pressure to the oil pump causing the weak firing of injectors under acceleration??
you need toi have a scanner hooked up to see what all of the sensors are doing.icp detects what the ipr is doing.when more throttle is commanded the pcm increases the ipr.i would do a cylinder contribution test to isolate the cylinder that is giving u issues.if the ipr is being commande to a certain pressure and the actual pressure is lower ,either the ipr is faulty or the hpop is able to build enough pressure to keep up with the demand.
JRJ04
Senior Member
The ICP Sensor is indeed on top of the driver's side cylinder head towards the front of the truck. The IPR, is screwed in to the back of the HPOP. It is almost directly under the fuel bowl. I think it can be removed without removing the fuel bowl, its a tight fit.
Does anyone have a good how-to on removing/cleaning and reinstalling the IPR?
The Dude
Full Access Member
I pulled out the Ipr on 5 minutes! take off the wiring than undo the brass nut 3/4 wrench, pull of the wiring then sleeve I believe it`s a magnet then put a 1 1/8 deep socket on the ipr and pull it out carefully not to wreck the orings!!