2002 7.3 hard start and looping

evans213 · Feb 17, 2019

So after being out of the 7.3 (and any other diesel) world, Im back in!!! I picked up a 2002 CCSB 4x4 7.3 has a TS 6 position chip, and bully dog air filter and housing(I know nothing about them are they good or bad? I may order a 6637 kit like I used to have on my 97). The original motor dropped a cylinder and the PO put a used motor in that ran good and had good compression. When he did this, about a year and half ago, he also put in new injectors, glow plugs, glow plug relay.

1). It has a continuous cold start issue, if you plug it in it will start after a few cranks and letting the GP warm up a few cycles. I am going to meter check the relay and stuff, as maybe its went bad? If not anything to do with the GP system, where should I go from there? HPOP, IPR, ICP(read bullet 2)?

2). Yesterday while driving it, it just started to loop randomly and didn't through a CEL. I switched the chip over to stock and it continued. I unplugged the ICP and it stopped, plug it back in and it starts back, so I left it unplugged and the truck ran flawlessly. I thought well I could have found the cold start issue. I have a spare ICP I am going to through in it, as the one in it also has oil in it so I know it has to be bad, correct? I left the ICP unplugged and it still has a horrible cold start issue(see bullet 1).

It came with the original motor, complete and literally a truck bed of other parts. I am going to completely rebuild the original motor (machined block and heads, injectors, complete rebuild kit, have Rosewoods diesel rebuild the original injectors to stage 1.5s, new HPOP (I used to have a T500 running stage 2's in my previous 7.3 but read no one can reach the Terminator guy anymore so have to look at other options). I am going to build it mild this time for reliability, as we regular pull a 32' travel trailer on family camping trips.

EPA · Feb 17, 2019

Change the Icp... It only takes a few minutes. Make sure the Icp pigtail is not saturated in oil... I had one that pushed oil into the wires yes under the wire insulation the oil made its way up about 2 inches into the pigtail.. I had to cut and replace those wires.
And check/test gp relay, harness, gp's

Any excessive smoke on cold start? Does the truck run crappy at first then clear up?

evans213 · Feb 17, 2019

Thanks for the response.

When cranking the truck on cold start there is just a little (barely noticable) haze of smoke. Once started the truck takes maybe a minute to clear up and runs great and no blue smoke, just a puff of black.

EPA · Feb 17, 2019

I think you're on the right track... Change the icp sensor its bad. Also inspect pigtail.. And test glow plug items including valve cover harness. See what changes come with that. Could have some slight injector stiction going on. But definitely start with those stated items.

evans213 · Feb 19, 2019

Checked GPR this afternoon, it has power on one side with the key off and power to the other side with the key on. So it should be good. The only way to check the VC gasket is to remove the valve covers correct?

HPOP gasket is leaking, oil cooler appears to have a leak, and the pedestal O rings are leaking. Going to do the ******d pedestal from RiffRaff when I do those O rings, may even go ahead and do a T500 HPOP when I fix that gasket.

Probably going to take this over to a build thread.

Arisley · Feb 19, 2019

Think about an Adrenaline HPOP.

You can check the gaskets with an ohm meter without pulling the valve covers. There ia an ohm reading from the connector to ground. It is pretty low, but I cannot remember what it is.

lincolnlocker · Feb 20, 2019

evans213 said:
Checked GPR this afternoon, it has power on one side with the key off and power to the other side with the key on. So it should be good. The only way to check the VC gasket is to remove the valve covers correct?

HPOP gasket is leaking, oil cooler appears to have a leak, and the pedestal O rings are leaking. Going to do the ******d pedestal from RiffRaff when I do those O rings, may even go ahead and do a T500 HPOP when I fix that gasket.

Probably going to take this over to a build thread.

First off, just because there is voltage on both posts of the gpr doesnt mean it is good. If there is 1/4 of a volt or more difference from the always hot post to the key on post then it is junk..

Second, what oil are you running and how many miles on it?

live life full throttle

evans213 · Feb 20, 2019

I will check the GPR with a digital meter today, used an older gage style meter that had the arm. So so probably not real accurate down to the 1/4 volt, lol. It is a white Roger(stancher) GPR, PO said he put it in along with new injectors and GP about a year and half ago. But that doesn't mean anything.

The PO is running Rotella T5 15w-40 in the truck right now. The body of the truck has 378K, the motor thats in it has roughly 250K. I have the original motor, my plan is to rebuild it and do stage 1 injectors, HPOP, ARP studs, 910 springs, and a bigger turbo wheel. My previous truck had Rosewood Stage 2's 180cc/100% with supporting mods. It was a little obnoxious.

I just ordered the Riffraff ******d turbo pedestal, with O rings, oil cooler seal kit, and HPOP gasket. When I do those items, I will obviously be changing the oil. I will probably be going to 5w oil at that time.

I have a truck bed full of parts right now that I have to get off loaded and go through, there I will spare ICP and get that fixed if its good, if not ill order a new one. Literally, there is a complete motor, wiring harness, complete dash with wiring harness, and loads of other parts.

evans213 · Feb 20, 2019

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lincolnlocker · Feb 20, 2019

Wow. That looks great for that many miles on it!

Yeah, id say it is ready to be freshened up on all accounts.

I wouldn't necessarily be set on 5w40 in a 7.3 either. I have had the best luck with chevron delo 15w40 over the counter oil until i and many others switched to lubrication engineers 8700 15w40...

Definitely switch to the 6637 or i prefer the Donaldson version better. Its hydrophobic. The napa filters are not.

live life full throttle

evans213 · Feb 20, 2019

Thank you. Believe it or not but the truck came out of West VA, so it’s seen plenty of salt. It only has very minor rust(just bubbling) above the rear wheels and the passenger side rocker panel is starting to rust. I have been detailing the inter this morning and it is in great shape. The seats show a little wear but not tore all to pieces. I’ll get some pics.

evans213 · Feb 28, 2019

Well, I believe I have narrowed the looping problem down to the ICP, as it runs smooth as silk constantly with it unplugged. It will kind of loop when coming down to a idle, RM meter doesn't bounce, the motor just loops a little coming down. I have a new IPR I am going to put on it as well.

I tested the GPR with a Fluk meter, it read 12.5v with the key off on constant terminal. With the key on, it read 0v on the GP side. So I believe that to me my problem. I dont understand why the cheapo meter read power both times though? I may recheck it again. the truck starts like a champ when warm or it has been plugged in for a while.

Parts so far that I have ordered, and will possibly turn this over in build thread:

-New HPOP gasket (current leak there, may go ahead and get an Adrenaline pump as well because I will be upgraded injectors in the future and will have the HPOP to replace gasket)

-New EBPV ******d pedestal, ******d turbo outlet, and the wiring plug from RiffRaff (pedestal O-ring leak, might as well get the parts I want to put on now while its apart)

-New oil cooler gasket kit (leak there as well)

-6637 intake kit with donaldson filter

-going to double check the GPR but will probably be ordering a Western Snowplow relay

-Sway Bar end link kit Energy Solutions (started thumping and popping over ever little bump in the road, will continue to do it for a while then it goes away)

-going to change oil out to LE8700 when I do oil cooler

evans213 · Mar 27, 2019

Well I'm waiting on my LE8700 oil to arrive before I start tearing stuff apart. I did the end link and sway bar bushings and still noticed a slight clunking noise. Jacked the front end up and found that the ball joints on the drivers side were shot. Replaced those with Moog's and the truck drives great now, and no clunking.

I replaced the GPR with a stancor and also had to replace both batteries(as one of them had a bad cell), that didnt solve the cold start issue I'm having. Tried Ohm'ing the GP's and got between 1-1.8, that seems a little high to me but not out of spec by being over 2(from what I have read anyway). What say y'all?

I have a spare starter I may throw on it as well, it seemed to crank a little slow yesterday. Batteries are reading 12.5 volts.