I have a 96 F250 that will start fine cold but will not restart once engine is warm until you give it a little time to cool out. Both batteries load check great, replaced starter as it was getting very draggy. I have put rebuilt injectors in it in the last 6 months. High pressure oil reservoir is full. I did have to reoring a couple injectors a while back but while that was going on, I was always losing oil out of the high pressure reservoir. The fuel filter bowl is the right color. I assume that the high pressure pump must be weak. The Scan Tool on the laptop shows over 500#s pressure on cold start and peaks at 2600-2700# while driving under load. On a hot restart, it only shows 270#s at 200 engine rpm.

From the information here, do you agree or disagree on the high pressure pump or is there more diagnostic work, yet?

Thanks
Kelly

 

My bet is for the IPR

 

X 2 for IPR o rings .....

 

IPR o-rings FTW!

 

x4 ipr o-rings

 

Hey kelro, ya think it might be the IPR o-rings?

 

I'm going to go out on a limb and say it's the IPR O'rings

Click Me-----> IPR O'Ring Replacement

 

Maybe no ones though of this as yet but maybe its your IPR O rings?

 

I put a new ipr in while I was messing with the injectors and putting in a new mechanical fuel pump. Are you talking about external orings or internal orings or both?

Thanks for the help

 

External o-rings There are 2 o-rings and a backer ring.

 

i say injector orings!! i bet a top one is blown out

 

OP said...:

have put rebuilt injectors in it in the last 6 months. High pressure oil reservoir is full. I did have to reoring a couple injectors a while back but while that was going on, I was always losing oil out of the high pressure reservoir.

 

still could be inj orings he said he replaced a couple not all of them.

ive had non alliant orings only last a few months and pullin valve covers to see if its barfin oil out the top

 

Update on it.

I put in the IPR orings (buy from IH for $29-Ford is roughly 50). Still same problem as it starts fine when engine is cooled out but will just crank and crank but no smoke or fire until engine is cooled out some. I thought maybe my new IPR was bad so I put the old one back in but it has the same symptons nad doesn't cold start the engine quite as fast. I haven't disassembled either valve-should I have checked this out or do I have 2 bad IPRs or some other problem.
BTW- Orings on both IPRs looked good to my eyes.
Thanks

 

You are going to have to set up a guage to measure the HP oil pressure in the heads , one at a time & isolate the pump ,,,



Here is what is needed to put a gauge together thanks to Swamps site.

If you don't have access to a scantool, then go to your local hydraulic supply
house, and have them make you up a mechanical gauge. You might spend $60
or so on high pressure hose, fittings, and a quality 0-3500psi liquid filled
gauge....but having this hose available for future diagnostics might be more
valuable than you think.
The hose which you will need will need to be about 40" long, rated for
(minimum) 3000psi working pressure (12k psi burst rating!) with the gauge on
one end, and a #6 female JIC swivel fitting crimped onto the other.
You will also need an individual fitting to screw into the head to go from the
head to the hose.
This single fitting will be a 90degree fitting # 5 "male boss" (sometimes called #
5 o-ring) on one end of the 90, and a # 6 male JIC on the other end of the 90.
Our local hydraulic shop would label such a fitting as 5MB-6MJ90
"JIC" is nothing special...it's just 'hydraulic talk' for a 37degree flare
fitting...standard hydraulic stuff here...nothing rare by any stretch.
Looking at the top of (either) cylinder head, you'll see the factory stainless
braided oil lines (one to each head) then you'll see a few bronze colored
plugs... (Engine off, of course) Using a 5/8" wrench, remove any one of the
bronze plugs, and install the 90deg fitting into the hole. (save the plug for
reinstallation , after testing). and the O-rings are reusable, unless brittle,
cracked, etc...
The single 90deg fitting will have a "jamb nut" on the O-ring side...screw the
fitting into the head, "aiming" the 90 away from the turbo, intercooler pipes,
etc...and then tighten the jamb nut, to "squish" the O-ring also locking the 90
from "spinning" around as you attach the swivel end of the hose to the 90. No
sealants, loctite, or teflon tape are needed on "JIC" or O-ring fittings...and
don't overtighten them...usually about 180degrees with a wrench past finger tight.