New member hello and asking for noob help

[vintagecarlover]

Hi all, new member with a no start issue. Trucks have always started even after sitting for a while between visits but last time cant start truck. 2 strong batteries plus jumper cables to running nissan pickup to the primary battery. starter just rebuilt last week. It turns well, and gets fuel to the fuel filter without issues. cracked injectors loose to bleed and not getting much going on there so i closed them all back up. I did need to replace one section of small rubber fuel line between rear injectors on right as i saw it leaking from dry-rot. the rest were good. checked all glow plugs on right side and all were good just ran out of daylight and will check others in am, (ohm'd out).

Im trying to learn all the diesel terminology but still need help. I have a different fuel distributor than ive seen pics of online, (pmd?) didnt see anything that looked like a roll of quarters?? and cant find any kind of lift pump on the frame under drivers seat. glow plug light on dash comes on with key switch and goes out after 4 or 5 seconds. thought i needed to bleed injectors but dont know diesels yet. any help here REALLY appreciated. i have tools but no obd1 scanner. my other truck is running so i have the luxury os swapping parts off it but dont know where to go.

where is any relays responsible for no start?
where is and how to check computer?
what is next to check?
thanks in advance. Mark

[phantom309]

Do you have a throttle cable that manually moves an arm on the side of the injection pump?

If so,. the engine doesn't have a computer i think,.so no pmd etc,.and the shutoff solenoid is under the top cover where the return line comes out

[vintagecarlover]

thats a yes on throttle cable on the pump. can u be more specific on shut off solenoid location?? what kind of troubleshooting can i do? any links or good threads would be great. thx for answering as im having a hellofva time getting any feedback anywhere. 706 392 25eighty cell. regards mark

[bowtiebutler]

Mark, look at the top of your injection pump. You will see a fuel hose coming out of the top of it, and right next to the hose, there is a wire. That is the wire to your fuel solenoid. If you click on the picture I attached below, and look in the lower left corner you will see the wire I'm talking about. Not the green one, the one right next to the fuel return hose. To check your solenoid, leave your ignition key in the ON position, and go unplug the wire, then plug it back in. It should make a clicking sound. If not, then check to make sure the wire is supplying 12v. If it is, the solenoid is bad inside the pump, but I doubt it, as this is not a common problem.
If that checks good, then you may have air in the lines, or bad glow plugs.

You said previously that your lift pump is supplying fuel to your filter, but it will probably only cycle on briefly without the engine running, so to make sure you have the air out of the system, run a temporary jumper wire to the lift pump, and with the pump running, open the bleeder on the top of your fuel filter, and watch fore air bubbles. If you see air bubbles, continue to let fuel run out the top of the filter until no more air is seen. If you did see air pockets in this process, then it may still require a fair amount of cranking before it starts, and when it does start, it will run rough untill all the air has worked itself out.
If no air was seen during this process, and all you got was a good steady flow of fuel out of the top of the fuel filter, then its probably a glow plug problem. Just because the glow plug light comes on, on the dash, it doesn't mean the glow plugs are working, it just means the glow plug controller is cycling on. If the glow plugs are shot, they will not heat up.
Try these tests first. If you still can't figure it out, I'll give you a call tomorrow. Let me know.

Matt

[convert2diesel]

1st gen 6.5s in commercial chassis (step van, "C" chassis etc) were equipped with mechanical injection pumps but probably had an electronic 4L80E trans. Trans controller is located under the drivers seat.

There are two electrical connectors on the top of the injection pump. The one located at the front, is the fuel cut-off and the rear one is for the cold advance. With the key on, you should be getting 12Volts at both connectors with the engine cold. If not, check the wiring.

If you have the voltage, and no fuel, first check all the filters and the fuel supply lines. You may have a mechanical lift pump (located on the passenger side, front of the engine, same as on an older gasser). If not, your system has an electrical pump somewhere. Its possible they located it somewhere different on the step vans.

Check to see if you are getting fuel to the filter by opening up the water drain and either cranking the engine (mechanical lift pump) or by switching the key on and off (electrical pump only runs for a few seconds and than shuts off till there is oil pressure).

If you are getting fuel flow to the filter than you either have a plugged filter or you will have to remove the dome on top of the injection pump to gain access to the fuel cut off solenoid. Read up on the re-install process of the dome carefully. It can be a little tricky for the uninitiated.

Suggest you spend the bucks on some of the great information manuals offered here in the members area. Money really well spent for anyone trying to get familiar with these engines.

Good luck. Most on here more than willing to help out.

Bill

[vintagecarlover]

I'll be working on truck after while. I am getting 12v to the both terminals at the pump. I'll unplug at see if solenoid opens and closes. Yes mechanical pump works as fuel pushes as engine turns.

Matt my engine looks different. Maybe mine needs more bling and a wash. Lol

[vintagecarlover]

See pic

[Yukon6.2]

Matt my engine looks different. Maybe mine needs more bling and a wash. Lol
I think they call that patina now:D

[vintagecarlover]

i love patina as long as im NOT admiring it along the road side in a non runner, lol...

ok, matt or bill or anyone, i have power with key on on red wire to fuel distributer but not the green wire. that same green wire jumps over to some kind of solenoid where throttle cable or choke connects to fuel distributer.

what does this say? relay? can i jump this out or no? ive got a feeling we are getting close here. excited...

[DmaxMaverick]

The green wire is for the HPCA (Housing Pressure Cold Advance), and also goes to the high idle solenoid (as you found). This wire shouldn't be hot if the engine is warm. If the engine is cold and still no power there, the system "thinks" it's warm enough to not need it, for whatever reason. I'm not sure how it is for the 93 N/A's, but on previous models, it's usually a failed (closed) temp sender or grounded sender lead. Disconnect the temp sender at the rear of the head and test again. If you get power then, the sender has likely failed.

[bowtiebutler]

I'll be working on truck after while. I am getting 12v to the both terminals at the pump. I'll unplug at see if solenoid opens and closes. Yes mechanical pump works as fuel pushes as engine turns.

Matt my engine looks different. Maybe mine needs more bling and a wash. Lol

With the key on, do you hear a licking from the Injection Pump when unplugging, and replugging the red wire?

Matt

[vintagecarlover]

The green wire is for the HPCA (Housing Pressure Cold Advance), and also goes to the high idle solenoid (as you found). This wire shouldn't be hot if the engine is warm. If the engine is cold and still no power there, the system "thinks" it's warm enough to not need it, for whatever reason. I'm not sure how it is for the 93 N/A's, but on previous models, it's usually a failed (closed) temp sender or grounded sender lead. Disconnect the temp sender at the rear of the head and test again. If you get power then, the sender has likely failed.

no power to green wire plugged into temp sensor or not plugged in. should i try and jump power from red wire over to green while key is on?

matt, there is clicking on and off but think it comes from where the harness plugs in on top rear of the engine. definately a on off though. also found one open glow plug so ill swap one over from other truck to see if that matters till i can buy a set new. 706 392 2580 for quicker answers. really appreciate all the great education ALL.

PS. matt, my mistake when i said i had power to both wires. only have power to the red or hot wire. there is no additional clicking by plugging or unplugging red wire.