New IPR now no worse off.

[slyhog022056]

1997 F 250HD 7.3 powerstroke, Just changed out my IPR and couldnt get it to start, well after trying for a while but now the misfire is worse than before. Very limited throttle response. Where too now??? Took it for a test drive, made it 3 houses away and white smoke everywhere and wont go over 1800 rpm. i have no 12 vdc power to OBD port, fuse for lighter circuit still good, where woulod it get power from and which pins are 12vdc supposed to be on? forscan will not power on.

 

[Black dawg]

What symptoms was the truck having. Before replacing the ipr?

 

[slyhog022056]

Sorry for the late reply, life got in the way. It had been running fine for years, went to drive it to Ft Worth TX 40 miles away, about 2/3 of the way there it suddenly just started slowing down and within 2 miles it was at 10 mph in 2nd gear floored. let it set for and hour then made it another 5 miles. Towed it home and about 5 miles from the house it fired right back up under compression starting, unhooked the tow strap and went home at 25 mph floored and white smoke everywhere behind me. Got it home and let it sit overnight. Went out started as normal, revved it a few times, no issue, let it sit and idle for 45 minutes and revved it a few more times. Left out of the driveway and before I could get into 4th gear, began slowing down again and white smoke again. I have a forscan adapter but it wont power up, bought another one in case the one i had went bad, plugged it in ... no powerup. I have replaced CPS, IPR, fpr, valve cover gaskets and pigtails. It starts and idles but swings between 500 to 800 rpm then back to 500 rpm about every 3 seconds. Taken flir heat gun to look at the heat on the exhaust manifolds and all are within 15 to 20 degrees of each other. Try to drive, smoke everywhere within a few seconds. I am trying to find the OBD pinouts for the truck but none match what i have. I have 13VDC but not sure those are the right pins.

 

[u2slow]

A misfire suggests a problem with a cylinder or two, probably injector related.

Have you tried a leak-down test on the oil rails in the head(s)? I used a porta-power hand pump with some fittings and a gauge.

 

[slyhog022056]

Well before i replaced the head gaskets and pigtails cylinder 6 was about 80 degrees colder than the rest, that went away but after it started running bad again I only saw 30 degrees at the most between cylinders. i need my truck, yes but i cant keep dumping money into it. If I can find the correct pinouts for the OBD port then my Forscan would help me narrow it down. It is a 97 and only has about 370,000 miles on it but the cab is junk so i cant get much for it at all. I can rebuild the injectors my self for under $600 but would like to know if there is something else that I am missing.

 

[u2slow]

I chased my tail on a higher-mile '97 also. I threw a CPS, and an lpop in it - no difference. Then I had to start troubleshooting for real.

Electrical testing of the injectors and glow plugs revealed only one dead glow plug. The leak-down test was very rewarding. Proved to me there was no oil bypassing injectors or going anywhere else.

At that point, I got a hold of a used '99 hpop and new ipr. It behaved (well, mainly started) much better after than. That was enough to sell it.

Had I hung onto it, it would got new injectors, and also dropped the pan/timing-cover to ensure the oil pickup hadn't come loose from the timing cover, and those essential check valves for oil flow were fully functional.

 

[slyhog022056]

Now that you mention it when i replaced the valve cover gasket and pigtails on the drivers side i had 1 injector that wasnt squirting oil back into the head but after it warmed up it would squirt more than the rest. I just cant understand why it would run and idle fine but as soon as i get 3 houses away from home i could hear and feel it start missing and smoking every single time. Pull it into the drive, shut it off and restart a few minutes later and act fine again. I tried changing my CPS with 2 new ones, wouldnt even start up with either one and i know they were fully seated.

 

[frankenwrench]

Not saying this is your issue, but last year I ran into this with my 97 cclb. Changed injectors and valve covers with harnesses and all went away.

 

[slyhog022056]

Well since I cant read the OBD port I will buy a rebuild kit and rebuild my injectors. In the mean time I will buy a cheap $6000 truck to get by.

 

[Rdnck84_03]

On the obd port not working, there is a fuse for the power wire. I do not remember which one it is, I seem to recall that it is also the same fuse as either the power point or lighter circuit.

If one of those isn't working I would check for a blown fuse there first.

James