Where to check next

[GreMonte]

Here's what I have going on with my 97 F-250 4x4 with the 7.3 auto tranny. Its also stock as far as I know. About 218000 miles

The truck runs fine when cold. The truck starts ok when cold. It does blow white smoke and has a top fuel idle when is first starts. I can wait it or rev it up and it idles fine. Power is good when cold.

Once it warms up its a different story. It shakes, at idle when in gear, when backing up you can see the bed shaking. It can barely get out of its own way until the turbo spools up and the turbo lag is much more noticeable and seems longer. Also its a PITA to start when hot. Most times I have to put my foot down while cranking to get it to start and it takes a lot of cranking. It tries to start but just a little sputter.

I took it to a shop to get it checked out. They seem to "need" to get the injectors out first thing (because it costs $1500 I'm sure) but I think there can be other things checked first.

So far I have replace the glow plug relay, the shop said I had high resistance on the old one. I have changed the valve cover gaskets and harnesses including the pig tails and replaced the glow plugs. I have done two oil changes to "flush out" the bad oil as the shop suggested. And the fuel filter is new.

I don't want to pull the injectors until I have ruled out everything else. Any idea's and help would be great and thank you in advance. I want to get my truck running right before I start making it run better.

[Patrick Feeley]

I would probably run it (when warm) with the valvecovers off and look for oil leakage around the base of the injectors. You may be getting High Pressure Oil System presuure bleed off from that. You can also check the Injection Pressure Regulator (IPR o-rings and see if they're bad (although if you're going to remove it to check them, you might as well replace them ... only about $30). You might have them check the Engine Oil Temperature (EOT) sensor for accuracy too. Cheers!

[GreMonte]

Originally Posted by Patrick Feeley

I would probably run it (when warm) with the valvecovers off and look for oil leakage around the base of the injectors. You may be getting High Pressure Oil System presuure bleed off from that. You can also check the Injection Pressure Regulator (IPR o-rings and see if they're bad (although if you're going to remove it to check them, you might as well replace them ... only about $30). You might have them check the Engine Oil Temperature (EOT) sensor for accuracy too. Cheers!

Great info thanks. I have been circling around the IPR for a while but I didn't know about the rebuild, I think for $30 I should just do it anyway. Also the EOT sounds like a good thing to test too. If these things check out fine and the engine still runs rough I guess its time for injector seals. I will take the injectors down for testing too.

[GreMonte]

Ordered the seal kit for the IPR. I'll let you know what happens when I install it.

[GreMonte]

I rebuild the IPR today.

I got it out and apart and didn't loose anything. The components were all in good shape and felt like they should so I added the new O rings and put it back together.

The idle is so smooooth now. The truck had more pep and even sounds better.

That's why I want to do all the work myself. Took it to a shop and they had me chasing my tail and the FIRST thing they wanted to do was yank the injectors.

Would have been a $30 fix had I started here first. So I bought a lunch and a little rum and now I will wash my truck, and sit outside in the sun and pat myself on the back

Thanks all

[nra1ifer]

Glad to hear you got it fixed. Nothing like something running like it's supposed to! And, you fixed it yourself.... even better!

[GreMonte]

So my victory seems to be short lived. The truck has returned to its old ways. Very hard to start when warm, shakes at intersections( I little less but not much) and that top fuel idle for the first 3 seconds after starting.

So.... what next? Replace IRP completely? Injector seals? HPOP?

I guess I'm done throwing cheap parts at it and now it time for some expensive ones. I really want to do some upgrades like stack exhaust and a chip but not until it runs right.. errrrr

[GreMonte]

Pulled the injectors and installed new seals (OEM) also built a DIY Napa gold intake.

Still have a rough idle when warm and a really bad idle when first starting when warm. Tach jumping, lights dimming, truck rocking, top fuel idle.