What a dead horse

[iluvbudwsr]

"when it rains it pours"! I have been reading thread after thread using the search feature and I'd like to get a few ideas before I go through more money! I've been spending so much money on this thing lately im about to give up. I've had a problem with hard starts ever since I bought it. The fellow I bought it from said it had a pin hole leak in one of the fuel return lines. I replaced all these among several other fuel lines. they looked alittle dry just from being an 84 model but I did'nt see any leaks or any of the sort. When I cold start it, it fires up and then hesitates and dies.on the second try it hesitates like crazy but it will finally fire. I can drive two miles and shut it off and run into get a soda and come back out and it fires right up. If I drive it for more than 30-45 minutes and leave it sit and try to start it it wont fire. I've checked the glow plugs and everything is fine. Im starting to get alittle iiritated so I took it to my local mechanic and he did'nt even want to fool with it so I called a mechanic friend of mine and he said with 70,000 miles on it, it could be time for a new fuel pump. I priced one at autozone and the computer said they're only 26$. Does this sound like like a fuel pump problem? I've checked and replaced most of the fuel lines. Any help here would be much appriciated guys!

 

[that1028guy]

More like a possible injection pump. When they start getting weak they seem to get hard to start. Does it act like its loosing prime? Do you hold the peadal down about a 1/4 way down when you crank and it helps?

 

[iluvbudwsr]

I sure do! I still hesitates but fires up. But sometimes after driving it for 30-45min it wont start at all. I give it a small shot of WD-40 on the air filter and it helps it come to life but I dont like doing that but it beats being stranded.

 

[MakersTeleMark]

An IP costs a lot more than that, but it is symptomatic of your problem.

 

[iluvbudwsr]

Hmmmmmmmm! it seems like all my pay checks have been going to this thing. New Radiator...400$ installed...Belts...batteries...ect.....! Im about to give up...LOL... It used to be fun but now its eating a whole in my pocket. I want to take some road trips but at this point I cant rely on it..

 

[m38inmaine]

If it's hard starting hot more than likely the injector pump needs replacing. Good rebuilt pumps can be had for under $400 but installing it is labor intensive. Don't give up yet, your'e almost there.

 

[iluvbudwsr]

I hope she'll hold out for a few more paychecks then. i'll have to start looking now then and see if I can find a nice rebuilt one. man, I'm gonna ave a whole new truck by the time im done with all these upgrades!...LOL

 

[Cucvnut]

I got mine from Pensacola fuel injection. It was 345 shipped with no core and a one year warranty.

 

[2INSANE]

Open your hood. Look at fuel filter mount. See the knob on top? Make sure it's tight. While your at it. See that nipple next to the knob? Yea, get a rubber hose put on nipple and suck with your mouth. Any air? Any fuel? If so... The knob is loose and your getting air in lines. Try that. Don't give up! Think for a sec... How much your saving by not having another project, loan, higher insurance. Keep up with replacing parts till you get her right. Keep testing! Keep us posted on this.

 

[2INSANE]

Have you dropped fuel tank and replaced those rubber hoses yet? I have same problem you have with my 83 GMC civilian truck on the pass side tank. It was the tank rubber hoses....

 

[dstang97]

Most common fuel leaks are fuel filter base and lift pump. Check them first and it could be loosing its prime.

 

[cpf240]

Perhaps put a clear section of fuel line in place either between the lift pump and the injection pump, or on the return line from the injection pump. Then you can see if you are getting air in the lines.

I've read many accounts here about the stock fuel filter base causing air leaks, so it is a good place to start.

If you have not done so already, I would also suggest going through the glow plug system to make sure they are working properly.

 

[iluvbudwsr]

@ 2INSANE; I tried your suggestion on the fuel filter and it was a no go. still a hard start with a good bit of white smoke with slight pumping on the pedal ....it was worth a try though...

 

[cedargrove]

Once you have it running, how does it drive? Sounds like the problem is just hard starting. I haven't heard any complaints about it running poorly once you get it going. This makes me think that the injection pump may be fine.

I do suspect an air problem though. Try this...Go to Autozone and get a fuel cap that fits your truck. I use Autozone part #6819. It has a little vent button in it. While you are there pick up a tire valve Autozone part #20004. When you get home take the fuel cap apart and remove the vent button. Install the tire valve in that hole and reassemble the fuel cap. You may have to drill the hole in the cap to get the valve to push in. I also used a drill press to try to force the little booger through.

Once you have that together, place this fuel cap on your truck. Apply about 5 to 7 psi to your tank and then start looking around for wet spots. One place that is hard (impossible) to see is the top of the tank where the hard lines enter so you may need to just feel around up there. Hopefully this will reveal the place (or places) where your system is sucking air.

Also on the hard starts when hot...This might be a seperate issue. I had the same issue on a civi 6.5. Turned out to be a bad starter. Actually come to think of it, I had both of these issues. Since my truck was sucking air, it would be extremely hard to start if it sat for a day or two. This eventually took it's toll on my starter. When the truck is cold, you only need about 100 rpms to fire it off. When the truck is warm you need something like 180 rpms to fire it off. The first thing I did was find and repair my air leaks (metal tubing along frame rails rusted thin and sucking air) and then replaced my starter. It's all good now.

It did take me a long time to convince myself that the starter was the cause of my hard start when hot issue. The starter seemed to me to be turning over pretty well and it wasn't until I replaced the starter that I realized how tired it really was.

The other thing that threw me off was that I could douse the injection pump with about 1 liter of water when it was hot and I could then start the truck. Seemed like a pump issue but I really didn't want to go there. The thing ran great once it fired off so this made me think it wasn't really the injection pump. Decided to try a starter and got lucky.

All of my experience with these trucks is with the civi versions, but I think my advice still applies in this case.

Cheers

 

[unaffiliated]

The military version of these trucks have a larger fuel cap so you wont be able to make a pressure adapter from a civvy fuel cap.

 

[cedargrove]

The military version of these trucks have a larger fuel cap so you wont be able to make a pressure adapter from a civvy fuel cap.

Dang it!

Is it possible to swap the filler necks from a civi?

 

[2INSANE]

I do suspect an air problem though. Try this...Go to Autozone and get a fuel cap that fits your truck. I use Autozone part #6819. It has a little vent button in it. While you are there pick up a tire valve Autozone part #20004. When you get home take the fuel cap apart and remove the vent button. Install the tire valve in that hole and reassemble the fuel cap. You may have to drill the hole in the cap to get the valve to push in. I also used a drill press to try to force the little booger through.

Once you have that together, place this fuel cap on your truck. Apply about 5 to 7 psi to your tank and then start looking around for wet spots. One place that is hard (impossible) to see is the top of the tank where the hard lines enter so you may need to just feel around up there. Hopefully this will reveal the place (or places) where your system is sucking air.

Also on the hard starts when hot...This might be a seperate issue. I had the same issue on a civi 6.5. Turned out to be a bad starter. Actually come to think of it, I had both of these issues. Since my truck was sucking air, it would be extremely hard to start if it sat for a day or two. This eventually took it's toll on my starter. When the truck is cold, you only need about 100 rpms to fire it off. When the truck is warm you need something like 180 rpms to fire it off. The first thing I did was find and repair my air leaks (metal tubing along frame rails rusted thin and sucking air) and then replaced my starter. It's all good now.

That's a great idea! But instead could you use the AUX fuel line instead to do the test? Just tap off the other end and put air in the other. Hmmm ideas

 

[mistaken1]

I was all excited about being able to buy a new fuel cap.

 

[cedargrove]

That's a great idea! But instead could you use the AUX fuel line instead to do the test? Just tap off the other end and put air in the other. Hmmm ideas

I'm not familiar with the AUX fuel line. Just getting a little pressure on the system (however you can do it) should reveal the bad spots.

The filler neck on my civi just bolts to the body with 3 screws. I'm not sure what the CUCV set up looks like but I'd bet they would swap. Somebody send me a CUCV and I'll work it out.

 

[2INSANE]

I'm not familiar with the AUX fuel line. Just getting a little pressure on the system (however you can do it) should reveal the bad spots.

The filler neck on my civi just bolts to the body with 3 screws. I'm not sure what the CUCV set up looks like but I'd bet they would swap. Somebody send me a CUCV and I'll work it out.

There's 4 fuel lines on the tank.
1. Filler
2. Sender
3. Return
4. AUX/Over fill. This ones usually connected to the filler. Or cut and tapped off with a screw to keep air out.

I got a 6.2L diesel truck civilian Gmc 3/4 ton I'll sell ya. 6" lift $2500