Wondering if anyone could shed some light on my issue. First, here's what I have:
95 F250 4x4 Supercab 7.3 turbo, tymar intake, 3"-4" dp back exhaust, manual gp relay, re-built E4OD with shift kit. 240,000 miles. Last week I replaced my drivers side exhaust manifold gasket (had to use a torch to get the last bolt, near the firewall, off). She worked ok for a few days, then wouldn't start again (after she was already warm), but finally started when I floored the throttle. Now she starts normal, idles normal, but when I give throttle she shudders and shakes like a 3 cylinder, and just pours out white smoke (warm engine). The fuel filter was filthy and the bowl was full of rust particles. Replaced and cleaned. No difference. Could the heat of the torch done something?

 

Welcome to FTE. The heat of the torch on the driver side near the firewall is very close to the IDM (right above the wheel well liner near the driver firewall)

You said your fuel bowl and filter was nasty. Did you clean the screen at the FPR too?

 

Hey 350 - thanks for answering. I'm not sure what you mean, but when I had the pipe out of the fuel bowl to clean the bottom, I did see a small screen on the right side, half way up, about the size of a dime. Is that what you mean? I did run a Q-tip along that, but there wasn't much there.

 

That would be what he meant. Have you checked your valve cover gasket wiring? I don't know if that would be your issue, but its an easy check to see if you have any burnt pins (at least the outside connections are).

 

Hey 427 - I have thought of that, so maybe I should take that as confirmation. Do you know where to get new harnesses cheap? The cheapest I've found is ebay ($141.90 plus $20 shipping). Your thoughts...?? Also, I read somewhere an easy way to check the uvch is to disconnect, from the outside connection, one at a time. The one that doesn't make any difference is the broken one. Sounds good in thery, but when I disconected them, each one made it run worse. (??)

 

You said it idles normal and really misses when rpm's are applied right? That's probably not the harness then, do you see any burnt pins on the outside when you disconnected them? May be like Chris said and its the IDM. He's a lot smarter than me on the electrical side of these things so hopefully he'll jump back in. That or someone else can, I'll at least bump you to the top..

 

Have you checked the oil lately ?

May want to check fuel pressure as well..

Did you bump the ICP sensor while you were working ?

 

Yeah, it seems to start normal, and run normal, but when fuel is given she sputters and smokes like a diesel I didn't see any burnt pins, but I ordered the whole harness and gasket set, so we'll see then (have to do the gp's anyway...). I hope it's not the idm - from what I've come across in my searches, that's pricey. Thanks a lot for your help. Action, I did check the oil level, and it was 1/2 quart down. Topped it up just in case, but no difference. Oil is still fairly new (maybe 2,000 miles - I change oil on all my rigs often!!) Didn't check fuel pressure (don't know how to do that, but I'll find out). I'll try the ICP sensor tomorrow if this hurricane doesn't blow the truck away Thanks again guys.

 

You can test the fuel pressure on the schraeder valve on the FPR . You can use a regular tire gauge. Have someone rev it for you & test it at idle as well. Caution( messy )

 

Cool, Rick. Thanks for that. What is it supposed to read, at what rpm?

 

Let us know the fuel pressure, and don't put your tire pressure gauge back in your glove box after checking fuel pressure.

If we ignore the rest of your story, the no start when warm is often IPR related, so a couple of new o-rings and maybe pull and clean it might be in order if the fuel pressure checks good.

Why did you have to replace your manifold? Got a chip on the truck? If so, please remove it during the diagnosis phase so we can rule that out or it doesn't mask some underlying issue.

 

No, I don't have a chip yet . I pulled the manifold because the last bolt, the one by the firewall (drivers side) had rusted off, and the manifold was leaking. So, I bought a gasket set and went to replace it. All the others came off pretty easy, but the one that was broken broke right at the head, and there was nothing to grab hold of. So we started drilling....and heating...and drilling...and heating....to make a long story short (too late?), it took...are you ready....15 hours! But, we had to do it because it was the only bolt on the end, and if I didn't get it out it would still leak, even with a new gasket.

 

Ok, wind finally died down enough to work outside. Checked fuel pressure - while cranking 20 some odd for first second, the jumped to about 46
- while running - 46
Lots of white smoke. Decided to try and drive it. White smoke disapeared after a bit, then she seemed to run pretty much normal, except somewhat less power. No other problems noticed. Upon arrival I revved the engine in park, and still hesitates and blows gobs of white smoke. ??

 

Oh, BTW, I checked HPOP level just for fun. 1 inch from top, measured in the morning before I started her.

 

Mine did this and it was the IPR sticking. Check your wiring connections at the IPR and the ICP. Check the small tin nut on the IPR to ensure its not loose. Trace the wiring from the IPR and the ICP to the vally to ensure that there are not any bad wire spots. Remove the connector from the ICP and check for oil.

Check for codes before hand even if there is no indication of set codes by the WTS.

Have some one throttle the truck up to the sputter point and jiggle the wiring at the ICP & the IPR

Get it running and up plug the ICP and rerun the truck to see if there is a difference.