heres the story, ill make it short,

first will the oil guage still read if the switch is failing?

Already relocated pmd with fsd cooler on intake also pmd is newer according to previous owner. also lift pump is newer. The previous owner said the truck would stall every 15 min or when it warmed up and not restart. he had it towed several times and gave up on it thats how i got it. I drove it about 50 miles with no problem OTHER THAN truck would cut out upon heavy acceleration. The throttle is extremely responsive before i drive and after i drive before i shut it off. it took me a while to notice the cutting out since i wasnt trying to beat on the truck untill i changed the trani fluid and filter which i did yesterday. SO im driving yesterday and what do ya know PO238 popps up. (turbocharger/supercharger boost sensor circuit high according to my cpu.

I BELIVE it is probably failing ops based on what i have read. The owner before the po actually replaced the injector pump trying to fix this problem and the po replaced the lift pump . can i just use a normal fuel guage(someone said mechanical one?) attached to the hose that goes to the water relase brass nozle? im thinking of also maybe trying to just read the voltage. I also noticed that the hesitaton upon acceleration is only after driving the truck for a good half mile. WELL any and all help will be greatly appreciated i will be sure to keep updated if i figure it out. Im goin out now to work on it. Ps. the truck never actually stalled on me but im sure not waiting around for it to happen.

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well today when i went to start it it would not start! haha wow luck was on my side that this didnt happen when i was out driving. the previous owner was not lying... buddy is bringing over a pressure guage today and ima purge the filter as he turn the key to see what my pressure is like

 

P0238 could be leak in vacuum lines or the vacuum sol is bad

OPS will still let the truck being 98 now bad lift pump will not put 12V right to LP and see if it pump fuel buy opening the bass T- Valve at T-Stat housing be for i stay the PMD going south on you

 

is the lift pump running thats the thing and why do you always assume a PMD when it could be something easy?

 

well im not the one that relocated the pmd previous owner did . in case anyone happened to read over what i said the truck does not even start now. I did notice yesterday when i went to go try and start it i heard what i assumed to be the lift pump priming up as a fuel pump would do with the key on.(not the first time i heard this on this truck) I wanted to see what was making the noise so i hurried up and crawled under the truck and the noise was coming from the pump mounted on the frame. This is the lift pump i assume correct??? stupid question but are there 2 lift pumps or is this it?? the noise it was making did not sound right BUT it was absolutly a newer pump and the previous owner said it was brand new and it looked it. thanks for the advice i will try doing what you guys said soon as i get the time

 

yes that be LP should only be one LP , Not sure if you have 2 fuel tanks if they would run other LP

Also check and clean all the grounds and straps at the back on the motor on right side

Is PMD harness ground to top of IP also check harness with ohm test make sure it don't have short


first all i said may be the PMD going south
on 98 there few thing that keeping from starting bad grounds , glow plug system , LP , batteries , fuel sucking air or leaking and if all that passes then most likey PMD or IP PMD are know be biggest part trouble on 6.5
OPS will still let 97+ start if bad cause LP is running of it own relay

 

still havent got to test the lift pump yet but i hope to get to it today. the GOUND going to the pmd is screwed into the aftermarket fsd cooler. SOO that is a bad thing im guessing??? Also the grounds at the back of the intake have actually been redone properly with new connectors (i checked there all tight) so those are not the issue.

 

put ground that on the cooler back on top of IP

 

i havent yet relocated the ground but i did do something else. for the hell of it i went to go start it and still no start as i did that i heard a solenoid clicking on and off(found it to be glowplug relay) and my wait to start was clicking on and off(as it always did) well i looked in my handy dandy book and it said that that means i have possible bad glow plug. So i tested all the glowplugs and i have one thats bad. so the question is will one bad glow plug keep this baby from starting? im off to the store shortly to get a new one

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GOT IT RUNNING!!! well i was wrong about the wait to start flashing after the long cycle i guess thats normal from what i recently read. BUT i still had that bad glow plug. so i bought a new glow plug and put it in. I tested that one and the test light was bright unlike with the bad one which would only illuminate my light dull after repeated testing. THEN as i was reattaching the glow plug wires i noticed that nearly all of them on that side were not tight on the plugs so i squeezed them to make a better connection. I go to start the truck and after waiting for the glow plugs to heat it started up instantly. now i can finally get back to the po238 problem. Thanks for all the excellent advice greatly appreciate it!

 

Glad see you got it running

If you have a vacuum gauge that easy test for that 238 code

 

upon investigation i discovered that i had 25hg vac coming from the vac pump. when i put my finger on the line coming from the solenoid to actuator i could feel no pressure what soever even under acceleration. i made sure the line wasnt leaking so the solenoid must be shot. yeeppee