Truck Will Not Start - Diesel Forum

rebelboy194 · 02-23-2013, 05:23 PM

I have an 02 F-250 7.3L Powerstroke. The truck will not start in the cold. I have replaced glow plugs, glow plug relay, the glow plug/injector wiring harness, both batteries, changed the oil, changed the oil in the hpop, and changed the fuel filter to no avail. The only things left are the IPR, and the injector O-rings correct? It doesn't burn any oil, no excessive smoke other than the unburned fuel that gets pumped into the cylinders while I'm trying to start it. That just causes a white puff of smoke on start up and then it disappears. If I plug the block heater in, it fires and runs great. Also when I do get it to fire, it will run rough until it is warmed up then it smooths out and runs great. Also when it is cold and I can't get it to fire, it will turn over and a few cylinders sound like they are trying to fire every once in a while. I'm lost and don't know which one to replace in order to figure it out. Any help is much appreciated.

tinman13kup · 02-23-2013, 10:06 PM

Have you checked to see if the gp's are in fact coming on? How many miles on those injectors?

rebelboy194 · 02-24-2013, 01:15 PM

I wired up a light that comes on when the cold(driver side) lug on the gpr gets power so I could see if it was for sure working like it's supposed to. I haven't tested the gp's but I do know that while the relay is working it's like one or two cylinders will start trying to fire. When the relay shuts off then the truck just turns over and no cylinders try to fire. The truck has 240k miles on it, and I'm sure they are the stock injectors.

tinman13kup · 02-24-2013, 01:30 PM

I would say to check the gp's. They don't last forever, and just 1 bad one can lead to longer starts.

As for the injectors, with that many miles on them, tolerances are shot and poppet clearances can cause issues, especially with cold, thick oil. I'm up at 305K and have a few injectors that won't work until the oil warms up on cold (under 15*) days. They don't smoke, because they just simply are not firing.

rebelboy194 · 02-25-2013, 01:00 AM

I just replaced the glow plugs and the gpr with brand new ones. Would it help possibly if I switch to a synthetic lighter weight oil? I'm running Rotella T 15w40. I just changed the oil not even 1000 miles ago, but if it'll help then I'll do what I have to. I just don't have 1200 dollars to throw at injectors right now, and I'm trying to figure out how to get her started after an 8 hr shift at work where I can't plug it in. I appreciate the help and info

rebelboy194 · 02-26-2013, 01:17 AM

I just was thinking about it, and I remember that when I first got the truck and I drove it to work, I could jump the gpr with a screw driver and it would start. Now I was able to do this for a little while and then that quit working. I then replaced the glow plugs and relay. I'm wondering if the old relay went completely bad and that's why I was unable to jump it, and wondering if I got the UVCH plugged into the gp's good. Any thoughts on this?

tinman13kup · 02-26-2013, 07:08 AM

First off, YES, switching to a 10w-30 will help spin the engine faster for cold startups.

As for the old gpr being bad, it sounds like it was toast. You can ohm out the gps from the outer valve cover connector to check them. Just check the first 2 and last 2 pins on the connector to ground.

rebelboy194 · 02-26-2013, 04:19 PM

What should they show as far as ohms? I'm thinking I didn't get the uvch connected to the new glow plugs good

PATRICK4 · 02-26-2013, 04:43 PM

I feel like I've been sharing this link alot lately. Here is Klhansen's write up: Hard/No Start? Check here first.

If Klhansen gets anything for people viewing his write ups, he is probably doing pretty well this time of year.

rebelboy194 · 02-26-2013, 07:55 PM

Ok so I went and got me a multimeter, and tested the two front pins and two rear pins on each side. On the passenger side, I found 1 out of the 4 not reading anything, and on the driver side I found 3 of the 4 not reading anything. So I have 4 of them working and 4 of them not working, I'm assuming this would definitely cause a no/hard cold start situation?

INFRNL · 02-26-2013, 08:08 PM

Quote:

Originally Posted by rebelboy194

Ok so I went and got me a multimeter, and tested the two front pins and two rear pins on each side. On the passenger side, I found 1 out of the 4 not reading anything, and on the driver side I found 3 of the 4 not reading anything. So I have 4 of them working and 4 of them not working, I'm assuming this would definitely cause a no/hard cold start situation?

Thats would definitely cause issues in cold weather. Might be bad gp's, uvch, or just the connection coming loose.

rebelboy194 · 02-26-2013, 09:05 PM

Well I just put brand new gp's and and uvch's so I'm assuming my connections are loos, but I know better than to rule out bad new gp's and/or harnesses. I'm gonna pull the valve covers again tomorrow and ill check everything and see what the deal is. I appreciate all the help

INFRNL · 02-27-2013, 01:12 AM

I am not sure how much experience you have on these trucks.
One time I reconnected everything under the valve cover, but I tested before putting the cover back on and bolting down. I did not have a good connection on one of the glowplugs so I did not get a reading. It could be something as simple as that. maybe you got a defective harness, anything is possible. I guess you will know when you pull the covers back off..keep us posted
Also a note, now when I put the plug on the gp's, I take a sm flathead and make sure the gp connections are secure.

rebelboy194 · 02-27-2013, 06:53 AM

I'm not new to the engine, but this is my first time to do any real wrenching on this engine. I took my time and thought I had made sure all my connections were solid, but I guess we will see today. Just like I said, and like you said INFRNL, just because something is brand new doesn't necessarily mean it's in perfect working condition these days. One thing's for sure though this time, I will test everything before I put the valve covers back on.

rebelboy194 · 02-28-2013, 06:50 AM

So I pulled the valve cover on the driver side since #1 it's the easiest to pull and put, and #2 it was the side with 3 gp's not showing up. I cleaned the harness plugs and retested after making sure I connected them completely. Still the same, so I pulled one of the new gp's and cleaned and dropped one of the old ones in and plugged it in and it tested good. I got the same result with the other two, so I have 4 bad "brand new" glow plugs. I haven't done the passenger side yet, that will either be today or this weekend. I left it unplugged however so that I can see if this is helping/fixing the problem. It "should" fire up with only 1 bad glow plug in it from other posts that I have read. We'll see. Again thanks for all the help everybody.