Well I just got a call from the mechanic that has had my truck for a week and he basically said he don't have a clue what's wrong with it. He has a reputation as a good diesel mechanic and he has all of the latest diagnostic tools but the best he could come up with was it MIGHT be the HPOP or it MAY be a bad injector.
Here's a little background for anyone that may want to offer up some advice (please, please, I beg you!). The truck is a 95 PSD with 318,000 miles on it. Up until last saturday it started and ran like a new one. No kidding, it really did. While traveling down the interstate pulling my boat, I suddenly felt it lose power and the check engine light came on. At the next intersection I stopped and it idled fine but when I started to take off, it just sat there idleing for about 3 or 4 seconds before the rpms started to slowly increase and the truck began to move. I made it home, turned the truck off, disconnected the boat, got back in the truck and started it right up. No check engine light. I revved her up a time or two and it revved fine. Then it just quit and would not restart. Checked the fuel pressure while my wife spun her over and got a reading of 44#s. Next morning I checked the HPOP reservoir and the level was way down so I filled it up and tryed to start it. No go.. Had it towed to this guys shop and he called me the next day and said he had put a new fuel pump on because the presure was low but it still wouldn't start. I told him that had read 44#s of pressure the day before and he couldn't explain that. He was thinking that the engine oil pump wasn't pumping enough to keep the HPOP reservoir full and wanted to put a new oil pump in. I said ok and have been waiting for him to call me and tell me it was ready to go. Instead he decided not to put the pump in and now he's thinking bad HPOP. He does have it where it will start but when he tries to take it on a test drive, he gets to about 45 mph and boom, it switches to the safe mode or whatever you call it (power drops off) and the CEL comes on. Turn the key off and restart it and start all over again. He said that his scanner is showing a hi/low pressure on the oil from the HPOP. Sorry for all of the words but I'm hoping SOMEBODY out here can give me some advice here. Right now my plan is to go out to a salvage yard in the morning and get a used HPOP, swap it out and see if that does the trick.

 

if it's coming up with a hi/low pressure from the HPOP than it's PROBABLY gonna be the HPOP... he should be able to narrow it down if it's an injector issue or not by taking off the valve covers or something and seeing which injector is bad?? idk someone else knows what i mean... but if it's coming up with a code that has to do with the HPOP than that's probably what it is

 

have you checked the cps? you can get them for about $30 now and they're good to have a spare. they are known to cause erratic idle, no start, spotty starts, etc.

 

CPS is a quick, easy and inexpensive piece of mind that may get it going.

You should always start with freshly charged batteries and all the connections to them and the starter. fresh engine oil & filters too. This eliminates a lot of doohh! I should'a done that.

After your HPOP drained down or was found low it can take quite a while to get all the air out of the system. Fill the HPOP and drive it for 20-30 or more miles. IF it quits again, check the HPOP level. If it's found low the LPOP ain't keeping up with demand.

IF the HPOP is full and the engine still won't run you need to check the HPOP pressure. Your mechanic can do it with a scanner or place a gage in one of the ports in the head. There is aspecific test for checking the HPOP pressures in the factory service manual.

 

if the cel was on what were the codes? if its a pump problem you should get some icp codes, this shouldnt be that hard to diagnose. if the resevoir was low you have an oil issue, did he check the physical oil pressure? low and high, just for giggles did he do an injector buzz test?

 

Thanks for the replys from all of you. I really don't have all of the details of what he has or has not done right now but will talk with him face to face tomorrow. The CPS was just changed about 4 months ago and it really doesn't act like that is the problem. Whatever malfunctioned did it suddenly because like I said earlier it was running fine one minute and then not. I'll post back here tomorrow with an update. In the meantime thanks and keep those ideas coming!

 

What codes were pulled ? ask him if 1 or 2 or 4 injectors on 1 side of the block were showing bad.

This happened to us in Austin, and it ended up being just a burnt out injector wiring harness that sits under the valve cover........ seriously

1st it was showing 2 bad injectors - then it showed all 4 on another test - then on the 3rd test it showed 1 bad injector.......

It's easy to get to and find out, these are commonly burning up for some reason, atleast that's what I have been told.

JohnnyO

ps - the guys at Austin Fuel and Injection Rock !

 

Hi/low as in a P1211? That could be as simple as the ICP sensor. Or it could be a problem with the IPR valve. Or the IPR could simply be loose. OR it could have an injector harness fried.

There a lot of things to check before you throw a HPOP at it ($$$)

Was that the only code he pulled? If he's not getting an injector or an IDM code why would he bethinking about injectors at all?

 

If the HPOP was bad ,why would it come and go?...He needs to read the ICP & IPR duty cycle.. & was said before,,Check the connections to the valve covers,,,,,,,& the UVCH.......

 

I just sat here and typed a 700 word reply only to have it lost when AOL crapped out on me. Suffice it to say I paid the mechanic $504.11 today and my truck is still broke. Another guy is working on it now. Been a sucky day. I'll supply details asap.....

 

Did he check that wiring harness ?

JohnnyO

 

i feel your pain fast freddie i am in the same boat kind of

 

One way around that is to type those long reply's as a word document, then copy/paste it into the reply box. Can't lose it that way.

I know it doesn't help now......

 

Johnny, I've already been down the "burned wiring harness" road where the injectors quit working. That was about 3 or 4 months ago. This is nothing like that. The engine will start (that's due to a new fuel pump according to the mechanic) and idles and runs fine until you try to accelerate past about 45 mph. The burned wiring harness caused a distinct miss at all speeds. The code was indeed P1211 Cookie. He said he swapped out the ICP sensor with no change so he reinstalled the original. He basically said he didn't know what else to do except start throwing expensive parts at it so we parted ways. Several things I can't understand: (1) I checked the fuel pressure before I sent the truck to the shop and got a steady 44# while my wife cranked it over. He said they checked it and it would start out at about 40# but then drop off to almost nothing. They supposedly disconnected the fuel line under the truck and tried to pull fuel out of a bucket and the pump wouldn't do it. New fuel pump installed. (2) The morning after I had the initial problem with the truck I checked the level in the HPOP reservoir and it was way down. He said he checked it several times after he got it running and it was always full? I'm just hoping this guy that has it now is better on Powerstrokes. He sounds confident that he can put his finger on the problem pretty quick. We'll see...

 

Fast Freddie - our truck would run fine, then all of a sudden would go into limp mode, then resume normal operation after slowing down on the rpms....

It's something easy to check, it sounds confident that you are sure the wiring harness isn't the problem though.

As others have stated.... a HPOP($$$) may not be your problem. It may end up being your issue though... Also, we had a similar problem and changed out the CPS for that fix.

JohnnyO