No Start

[ipwizard]

Hi guys I'm new here and have been lurking for a while now.

I"m working on a family members '97 F350 7.3. We started having trouble getting it to start a few weeks ago and it just got worse to the point now it will not start.

I have been working on it for a couple weeks on and off, We changed the lift pump since it was leaking, Changed the O-rings on the fuel filter housing, and FPR. Replaced the CPS and fuel filter, checked the valve cover connectors for burnt pins (none found). The HPOP resivour is full of oil (not below 1 inch). Checked and charged the batteries monitored voltage during cranking and voltage dosnt drop below 10vdc. Also checked the GP relay and its operating as expected. The WTS light works, and there are no blown fuses.

I do have access to a Snap-On scanner with the diesel sup. I plan on doing a buzz test on the injectors, and checking pressures with it this weekend.

I thought about blocking off one side of the HP oil supply and seeing if it will start incase of a injector oil leak. Does anyone know what size the fitting is for the braded steel line?

Do any of you guys have any thoughts.

[Patrick Feeley]

I want to say they are a dash-6, but not positive (its that or dash-5). Check the wiring to the IPR and make sure the wiring is in good shape. Make sure the IPR coil is not loose and the "tin nut" holding it on is there and snug. Cheers!

[ipwizard]

Ok guess i should say im new to diesels (working on them atleast) can you explaing where the IPR is? is that the regulator on the HPOP?

[ipwizard]

Ok, looked around and the IPR is on the HPOP. We did end up changing that wiring harness that plugs into the IPR, Heater, ect. The seal on the IPR plug was all gummy and just fell apart when I unplugged it.

I'll check that nut and coil saturday.

Thanks

If anyone else can think of anything my ears are open!

[ianstew]

yep, get it scanned, that will def. help diagnosis

[ipwizard]

Looks like we might have found whats wrong. We scanned it with my uncles Snap-On scanner and it had a hard KOEO code of 1283 which is the IPR.

I checked the IPR and the nut and coil are tight, I pulled the connector and cleaned it also. We cleared all the codes and ran another KOEO test and it set 1283 again. So I'm off to Ford to pick up a IPR hope this will fix it.. They sure dont give those things away $211 my cost!

[Patrick Feeley]

It could be the IPR, the wiring, or the PCM (for me it was the PCM). Before you spend the bucks on a new IPR, I would do the following tests (NOTE: if yours is a California model 97 the pins might vary from this, but the ideas are the same):

X1 DIAGNOSTIC TROUBLE CODE (DTC) 1283: CHECK POWER FEED

DTC 1283 indicates an IPR circuit failure was detected by the PCM.

Key off. Remove IPR harness connector. Remove PCM relay. Measure resistance from IPR connector Pin A to PCM relay terminal 361 (R). Is resistance less than 5 ohms?

Yes: GO to «X2».

No: SERVICE open Circuit 361 (R). RERUN Scan Tool Diagnostic Test.

X2 CHECK IPR COIL RESISTANCE

Measure resistance of IPR coil. Is resistance 5 to 20 ohms?

Yes: GO to «X3».

No: REPLACE IPR. RERUN test.

X3 IPR CONTROL CIRCUIT SHORT TO POWER OR GROUND

Install breakout box. Leave the PCM disconnected. Leave IPR disconnected. Key off. Measure resistance from Test Pin 83 to power at Test Pins 71 and 97.
Measure resistance from Test Pin 83 to ground at Test Pins 25, 51, 76, 77 and 103.

Is the resistance greater than 10,000 ohms?

Yes: GO to «X4».

No: REPAIR short in Circuit 552 (Y/R). RERUN Scan Tool Diagnostic Test.

X4 IPR HARNESS CONTROL CIRCUIT -- CONTINUITY

Install breakout box. Leave the PCM disconnected. Measure continuity from PCM Pin 83 to Point B in the IPR regulator harness connector. Is there continuity?

Yes: REPLACE PCM. RETEST.

No: SERVICE open Circuit 552 (Y/R). RERUN test.

Cheers!

[ipwizard]

I didnt see your message until now. I replaced the IPR and that still did not fix the issue. We did check for voltage at the IPR connector and we got around ~11.9vdc (key on engine off). I can try to run thought the check list you posted and see whats up. We are suspecting the PCM but with the cost of them want to be sure thats what is bad.

Thanks for everyone's ideas!!

[ipwizard]

Patrick,

When your instructions say install breakout box at X3 are they refering to a breakout box on the PCM connector? I dont have a breakout box but I assume you could just go right off the pins on the PCM connector. IIRC The pins are numbered on the inside of the connector right?

I plan on running through your flow sheet tomorrow.

[Patrick Feeley]

Yeah, you don't need a breakout box for those tests where it tells you to leave the PCM disconnected (you would need it if you were installing the breakout connector and reconnecting the PCM to read actual live values). You can just go from the pins (it's kind of a PITA, but do-able. You will need the pinout diagram since there is something like 104 pins and they are not numbered on the inside of the connector. Am I correct in assuming your 97 is a 49-state version? If it is I'll try and doublecheck the procedure since it was from a 96. Cheers!