I think the relay is good. With the plugs cycling I get about 10.5 volts at both big terminals.

The starter is new, and seems to turn over pretty fast. My tach shows about 400rpm while cranking. I also have a new alternator and voltage regulator, and my batteries were both tested and passed.

I pulled the filter after the truck sat all night and all day, and it was overflowing with fuel as I took it off, and I have new return lines and caps so I don't think I have a major air intrusion issue. Also the truck starts excellent when plugged in. I did however notice that my filter has a leak on the bottom somewhere and drips fuel. I don't know if this could be related to my hard starting, but I will be replacing it soon.

I am hoping getting a new battery cable will help. There are a few bare spots on my positive, and it is very corroded.

Thank you all for your help. I will let you know how it goes.

 

I get aprx. 11V on both our '95s.

That contradicts what you said in post 6. Makes diagnosis difficult.

That could be a major factor.

 

Madpogue, I already admitted post 6 was a mistake. Please read all posts before commenting.

 

Update:
It has been pretty cold the past few mornings (below 20 degrees) and the truck has been starting very hard. After sitting about 10 hours it starts after cranking in 2 ten second bursts, and runs very rough and smokes a ton for a few minutes. After warmed up it runs well. If I shut the truck off for an hour or two, it fires right back up fine, but after a long period it is very hard to start.

I tested the voltage at the glow plugs and got about 9.6 V at each one, which appears to be normal. I bypassed the controller with a push button, and it had no effect on starting, so I put it back to normal.

I then put a clear line between the filter head, and the front passenger side injector cap, and got no air bubbles with the truck running. After shutting it off for a while, the fuel stayed in the line. Next I put a clear line from the rear driver injector cap to the line that drains to the tank, and with the truck running it had no fuel in it. Am I wrong or should this have fuel flowing through it with the truck running? Does this mean one of my driver side caps is leaking?

Thanks again folks.

 

As far as the return line goes, my "guess" would be that, you should have "some" indication of fuel returning to the tank. Have you revved up the engine on this test.
As for "no air bubbles" in your first test, you should leave the truck sit over night, then look for air.
If your caps are leaking, you should be able to see them leak.
Sometimes, as in my case, the injection pump may leak at the throttle shaft,
placing a scott towel under the IP, on the valley plate will show you if there are any leaks in that area.
White smoke is usually unburn fuel, maybe your giving it too much fuel on start-up.

 

Got new battery cables, a new fuel filter, and a facet electric pump, and the truck seemed to start a little better.

Today I tried to start it after it sat for about 3 days unplugged and it would not start. Cranked in 10 second bursts about 5 times and gave up. Plugged in for 30 minutes and it fired right up, ran at full throttle for a split second, and then ran normal.

Still have no fuel in the rear driver return line.

Starting to lose my mind also.

 

Well done on your trouble-shooting so far!

I have two thoughts:

Concerning the glow plug system, it's VERY common for these era trucks to have harness heat/corrosion issues. Find the two 10 or 12ga wires that are the hot leads(yellow on my truck) to your glow plug controller and follow them all the way back to the connector between them and the battery. That connector often melts from all the glowplug current and corrodes the wires at that connector. I bypassed the connector by splicing in some 10ga wires and that helped my glowplugs draw the appropriate amount of amps to get the job done properly. Some people re-do the whole line with 10ga or better.

Concerning the fuel return line:
Having a perfect seal in these return lines means that 16 o-rings and about 16 rubber hose connections all have to maintain a perfect seal under all the conditions we put them through, which even if you manage it, doesn't stay that way long. The best way I've heard of for fixing this is to put a check-valve in the return line, between the injector system and the fuel tank. I have one waiting to be installed so I can't say that it's worked for me but I've read about it many times.
The reason it works is that it takes 1-2psi to open a good check valve(not plastic), which means that it holds the fuel in the system when everything cools down and won't siphon back into the tank.

Also, check your valley pan to make sure it's not wet with fuel. If that's the case pray it's not the IP leaking and tighten up all your injector lines real good and look again. If the IP is beginning to leak you'd have these symptoms, I know I've been there...

Happy hunting!
-Joshua

 

Running straight wire from the connection at the starter relay (just a junction, actually) to the glow plug relay may be a good way to start a fire. Those two parallel "wires" running that course are actually fusible links. They're _supposed_ to melt (i.e. blow) when too much current flows through them. If they do, the cause of the excess current should be addressed and they should be replaced by new fusible links, not just straight gauge wire.

 

The 12v power wires you mentioned for the gp relay have been replaced with heavy gauge wire, and a fusible link. I did this a while back because the large connector was melted.

I checked under the injection pump and it doesn't seem to be leaking.

Thanks.

 

for some reason i never heard of that trick before, but it sure sounds smart!!
but of course, an electric lift pump will hide most problems

 

Yeah, sorry guys I forgot about the fuse link... my bad. That's very true for sure, don't forget that!

Yeah I'm excited to try it as my system works fine until the winter comes around and then every 3rd or 4th startup I used to bleed her due to air intrusion(now I switch my e-pump on for 20 seconds or so first). I don't want to rely on the E-pump I have so it's inline before the lift pump as a back-up only. While the switch is easy enough I also wanted to try this check valve thing to verify that it works and never have to worry about it again...

 

well, we must be like-minded. but while i did about the same thing as you, i added one little bit of added convenience to it: my e-pump is wired to run anytime the glow plugs are lit, plus any time i hold the pushbutton i attached to the bottom of the steering column.
i find myself wanting to have everything work as it should for a driver who only uses the factory controls, for example if my mom were to have to drive it for some random issue or whatever, everything she needs is perfectly controlled by the factory controls.
to wire it this way just used a standard 5 pin relay and a pushbutton switch. the relay's coil gets signal from the plugs side of the GP controller, the pump is on the common terminal, the battery on the NO terminal, and the pushbutton on the NC terminal, with the other side of the pushbutton going back to the fused battery hot of the NO terminal. perfectly automatic, but with manual override if i ever need it

 

I've been doing some research, and found that these trucks require batteries with 850 cca minimum. My batteries are 700cca and 800cca. Would it be worth it to get new batteries with higher cold cranking amps? Mine still test good, but seem lower than what folks recommend for these trucks.
THanks.

 

^^^^ Yes, absolutely. And NEVER have mismatched batteries. Always replace in pairs. They're connected in parallel, therefore one weak battery can pull the other one down.

 

I'd recommend at least a 1000 cca battery. I have to 1000s in mine and it cranks over pretty fast.