Got a 99 7.3 164k past 3 days been having a issue. Come outta work (nightshift) it's a little cool out got to crank the truck after the WTS light goes out and it doesn't crank like normal 2 or 3 seconds is normal. So I cycle the key and hold it on start and I don't know if it matters or not but it made me feel better bout it at the time I held my foot on the floor with the accelerator pedal. And I'd say after 10 seconds really wasn't counting she fired off and runs like normal. Then other day I was low on oil so I dumped some in hoping it'd help but same situation next morning. But runs perfectly after started and doesn't do this in the afternoons when I go to work. Also after I make it home I rechecked to see if it would do it after warmed up but no she cranks as if nothing was wrong. Myself and the truck are from Florida our whole lives lol. Im in Iowa at the moment and this is nowhere near the coldest it's been. 1st night here was 12in snow lol. Wondering what's causing this issue and what/how to fix it. Is it temperature related or just cold engine related. Never used the block heater before and I've had her a year. Any help is appreciated.

 

Have you checked the glow plug relay very common but I don't know if 56° is cold enough to cause it to have trouble starting. But it sounds like after you get some heat built up it fires off fine. So I would think the gpr is a logical place to start with the info you provided. There is a 7.3 powerstroke section on here maybe a mod will move this over there. Here's a video on how to test the gpr.

 

Thanks appreciate it I've been reading into this on other threads so I picked up a brand new gpr and cost today from the dealership because I just don't trust other part stores and they don't have a Napa from what I've found. Picked up a customer because it's a great item to have in the glove box for just in case. But as soon as I got them I went ahead and installed the new gpr and it still seemed a little longer than normal to start but the true test will be when I get off work in the morning when it's completely cooled off. So crossing my fingers.

 

Other things that could be a problem is the starter going bad, weak batteries, bad battery connections. Does it put out smoke while trying to start?

 

Well the starter turns just as great as when I bought it and strong too. Batteries are both brand new and only like 2 months old maybe 3 tops I'll double check the terminals to be safe and I haven't noticed any smoke but then again I really wasn't looking for any. I'm hoping the new gpr was the problem being I already replaced it (kept the old one for just in case) but if it does it in the am I'll be looking for white smoke.

 

OK well new girl didn't solve the issue. Had a buddy at the tailpipe and no smoke is confirmed. Any other ideas. Buddy is wondering if the lift pump in the tank is going out or if glow plugs went. Anybody got an idea

 

You might want to arc across the two big terminals on the GPR for about 30 seconds and see if that helps. Sometimes GPRs are bad right out of the box. I've had that happen.

No smoke out the tailpipe does indicate an electrical issue. But your truck does eventually start though?

 

Yes sir she does eventually start and I guess it's because of my gas burner habits when I hold my foot to the floor and I've tried to start it with a few 5-8 sec (approximate) cranks. And hmm I know these gpr's are pretty much the old starter solenoid's or at least identical to em suppose it won't hurt to try and arc it and see what happens. Little hard to do by myself though. Buddy happened to be walking by happenstance lol but even ones bought at the dealership be bad?

 

OK yall I got ahold of a new multimeter and the gpr tested good 12v on both big terminals with KOEO did it once when engine was warm and twice when engine cold. Now tested the one small terminal and i know its supposed to have 12v with the key off and when key on its grounded by the ecu or pcm i cant remember at the moment. Upon testing that particular terminal with the key on read 0.63 with the meter turned to the 20v selection (tested eveything at this setting) Is this ok or close enough to ground or did i have the wrong selection on the meter?Anyways i topped off the oil it was low. And changed fuel filter hadn't done it past 3 oil changes. Now once filter was pulled the fuel filter was jet black (I know shame on me but it happens when ya travel for a living and working on your right in motel parkin lots lol) but cleaned out fuel bowl best I could and installed new filter. Now it was mid day mind you but since I had been checking the gpr I had the key cycled a few times before start up but she started like shesome supposed to thought hey alright now that's more like it. Took and got showered up and got ready to leave for work and she took a lil bit longer to start than previous so not sure if it's completely fixed yet. Also again no smoke what so ever. True test will be when I get off work this early morning and see how it does. Fingers crossed that it's all good now. Will post findings later. Appreciate the help given so far.

 

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Sounds like the GPR Is working. 12v on both big posts with the key in the run position is good. Have you Ohmed out the glow plugs from the 42 pin connector on the valve covers? A solid 12v with the glow plugs fully energized.....I would expect it to be more in the 11/11.5 range. The GP's pull a heck of a lot of current.

Have you tried leaving the key in the run position until you hear he GPR de-energize( it make a solid clunk when it lets go) and then try to start it? The GPR can stay energized for up to 2 minutes on a cold engine.

What is the battery voltage while cranking? It needs to be at least 10/10.5v before the PCM will command the IDM to fire the injectors.

 

From the evidence I found in the toolbox from the previous/original owner he always ran amsoil 15w40 full synthetic heavy duty diesel and marine oil and I didn't want to mess that up so I've continued to run the same oil yes a lil pricey but good oil. Also P.O. had a amsoil bypass oil filter installed and ive kept up with changing that filter every other oil change as well (no definative mileage change suggestions even through amsoil just drain intervals) But tired injectors at only 165k? Not saying it's not possible but have seen em go a lot longer before needing replaced. And it's pretty strange that it's starting to do this as its warming up out , would've understood it happening when I showed up for the first night here in Iowa and it snowed 12" lol but anything is possible I'm living proof lol and God only knows where I'll be next to try and plug her in everywhere I go don't always have access to power and I know me that'll get old quick lol. Firm believer of preventative maintence and fixing whatever symptoms arise so if it needs it I'll do it, may not like it but I'll do it just exhausting other possibilities first before I start throwing big money at it.

 

Alright guys after two whole days of good cold starting I'm going to go ahead and say that the problem is fixed. So I'd say with the new grp and a good clean fuel filter and proper oil levels was the trick. Really glad it wasn't injectors just yet lol although I probably am looking to upgrade them as well as the hpop sometime within the next year. Getting ready to do a turbo upgrade here soon with a new turbo install kit from irate and add in a blow off valve. I sincere appreciate the helpful input and will be looking to/for more input on other issues and upgrades as time goes on. Have a good one everybody.