Hard starting

[gergstuff]

I have searched through quite a few threads on this issue but come away a bit confused...

Here is my story: I have a 1995 F-350 with the 7.3 turbo. I have only had it a few months. Up until a week or two ago it would start the first try after the "wait to start" light would go out. Then, rather suddenly, I would have to try 4-5 times to get it to start cold after letting the glow plugs do their thing longer and longer each time. It would start amid great clouds of white smoke.

After the first start it would start easily on a warm start.

After doing some research here and thinking I had some basic knowledge of the workings of a Diesel I thought it was bad glow plugs. So...I replaced all the glow plugs and even used new valve cover gaskets as long as I was in there. I got it all put back together and it started first try. Problem solved. Or so I thought.

Last night I went out to start it, and back to it's old tricks, had to let it glow a long time after a few trys at starting and again it fired up amid great clouds of white smoke.

Back to the forums and I dug a little deeper. I see many references to the glow plug relay, HPOP (which I gather is a high pressure oil pump?) fuel injectors and other items.

The relay is simple enough for me to understand.

Rather than just throw parts at it which gets expensive in a hurry, is there a tried a true methodology to try to isolate the problem?

I still don't get what the HPOP has to do anything.

I also read in one thread that glow plugs really don't have any impact on starting when ambient temps are about 50 degrees. I live in NW Washington and the temps have been 50-60 degrees lately.

If this is the case then maybe I am on the wrong track thinking it is glow plug related.

Any of your help and expertise is most welcome!

Thanks,

Craig

[BigFuel]

A weak HPOP will not atomize the fuel very well at cranking speeds. This means a larger (to almost liquid state of fuel) droplets and much harder for a cold piston to self ignite.A leaking injector can also bleed off oil pressure kinda quickly and the HPOP would then have to re energize the system before proper atomization of the fuel. Glow plug relays are a known failure point on a cold starting system. Simple fix as it is on top of the motor right next to the fuel bowl. Check the GPR fuse while you're at it. Test the relay by grounding one side of a meter and touching both heavy relay posts (not at the same time) and see if the voltage is good and consistent on both sides of the relay.

[gergstuff]

Well, I just went ahead and replaced the glow plug relay ($80!) and the truck started right up last night.

The acid test was this morning when it was rather chilly (39ish degrees) and again it fired right off so hopefully problem solved!

Thanks BigFuel you da man!

[BigFuel]

I just try to be helpful. Happy tugging