Isuzu SUV Forum banner
1 - 15 of 15 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter · #1 ·
Hello All,

So here's my problem. My 1995 Bighorn Auto 3.1TD 4JG2 4WD will crank but not start. When I turn the key there is a clicking noise coming from both the injection pump, (I have the electronic pump) and the glow plug relay. Checked for fuel at the pump, there is. Checked for fuel at injectors, nothing. So fuel is getting to the pump but not coming out of it. Paid a lot of money to a shop who said the pump needed to be rebuilt. So they rebuilt it, installed it, reset timing and everything was fine for about a week. Went out one morning and the clicking noise was back in the pump. Wouldnt start. No fuel at injectors. Towed it back to the shop that rebuilt the pump. For whatever reason when they tried to start it, it turned over right away, no clicking. They kept for a couple of days looking over the wiring and said they found some loose connections which they sured up. Each day they would start it and let it run for a couple hours, and had no starting issues. I went and picked it up and it started fine. All was good for two days. Tried to start this morning and the clicking was back in the pump. Won't start again. I've now paid to rebuild a pump that might not have needed to be rebuilt in the first place as the original clicking issue comes and goes, not to mention having to pay to have it towed twice. I'm assuming it's an electrical issue somewhere but nobody seems to be able to figure it out. Can anyone help?

Just for reference, new glow plugs were also installed at time of injection pump rebuild
 

·
Registered
Original owner, 1983 P'up LS (diesel)
Joined
·
2,691 Posts
Your pump may be electronically controlled, but the pump itself is mechanical. You won't get fuel coming out of it if the the engine engine isn't turning over. And yes, you may have spent money overhauling a pump that didn't need it. That happens way too often.

You said it "will crank but will not start". Then you describe clicking noises, but nothing like cranking. Your description sounds like it's not cranking (except occasionally). This sounds more like a starter problem. Can you please clarify?

Jack
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #3 · (Edited)
@Jack, thanks for your reply. It will crank until the battery dies, no problem there. The starter is fine. Engages no problem. it turns over but will not start. the clicking noise is repetitive(click, click, click, click, click, etc.) and is coming from inside the top silver rectangular cover on the injection pump. There is also repetitive clicking coming from glow plug relay but I was told that has no bearing and should still start as Im located in warm climate. When cranking there is diesel going to pump but not coming out of pump. It seems like the pump starts to work but with every click you hear its going on and off. If I manually prime the fuel it will start but does an up-down, up-down, up-down idle and then starves out of fuel. The up-down idling coincides with the clicking. for instance, every time it clicks idle drops
 

·
Registered
Original owner, 1983 P'up LS (diesel)
Joined
·
2,691 Posts
The repetitive clicking you describe (and the way it coincides with the idle speed dropping) sounds like it is the fuel cut solenoid. But that doesn't explain why manual priming would allow it to run. If the fuel cut solenoid is bad, priming wouldn't help. The fact that it runs and then dies one it loses prime makes me suspect that you have an air leak in your fuel line. This is probably the single most common issue with these engines.

When a fuel line develops a leak, you won't see fuel. Instead of fuel leaking out, the pump is sucking air in. One way to test this is to see if it will run from fuel in a plastic jug. Just get a piece of clean fuel line and connect one end to the inlet side of the priming pump. Put the other end into your jug of fuel. Prime it, and see how it runs.

Jack
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #5 ·
Ok, Jack. Thanks for that. Will try that later today and get back to you. BTW the fuel cut off solenoid was replaced when the pump was rebuilt..

Question though. what you described makes sense to me as far as no fuel, but what would cause the clicking

Also, kind of funny that you're the one replying. My name is John and both my dad and brother are Jack
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #6 · (Edited)
Hey Jack, raining here currently so cant try the external fuel line yet. However, I read on another thread somewhere that there is a cam sensor behind the timing case hidden by the AC and the alternator. They said if that sensor has faulted it would send a crank signal error and that there would be a clicking coming from that box on top of the pump from the governor clicking out. Are you aware of this?
 

·
Registered
Original owner, 1983 P'up LS (diesel)
Joined
·
2,691 Posts
Hey Jack, raining here currently so cant try the external fuel line yet. However, I read on another thread somewhere that there is a cam sensor behind the timing case hidden by the AC and the alternator. They said if that sensor has faulted it would send a crank signal error and that there would be a clicking coming from that box on top of the pump from the governor clicking out. Are you aware of this?
That sounds reasonable. I'm not at all familiar with the electronics related to diesels after 1987. In the US, we got the 4FB1 and the C223 --but no diesels after 1987. That may be why we haven't seen other replies yet. But the Bosch VE pump (licensed by Diesel Kiki) itself is essentially the same.
But if the crank sensor is the culprit, causing the solenoid to cut off, I can't see how manual priming would help. For the moment, I'm considering the noise a "red herring". If the fuel cut solenoid is 12v, you could disconnect its wiring and hotwire it to ensure it stays open.

Jack
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #8 ·
That sounds reasonable. I'm not at all familiar with the electronics related to diesels after 1987. In the US, we got the 4FB1 and the C223 --but no diesels after 1987. That may be why we haven't seen other replies yet. But the Bosch VE pump (licensed by Diesel Kiki) itself is essentially the same.
But if the crank sensor is the culprit, causing the solenoid to cut off, I can't see how manual priming would help. For the moment, I'm considering the noise a "red herring". If the fuel cut solenoid is 12v, you could disconnect its wiring and hotwire it to ensure it stays open.

Jack
I was told on another forum that since the governor is clicking in the pump that the ecu should be fine since its obviously sending signal to pump. Would you agree with that? Also, seems to happen after a hard rain. Someone had mentioned to me that there's an immobilizer ECU behind the kickpanel and that the wiring harness sits just behind the fender and can get wet in heavy rains or floods. Here in the Philippines, we've literally been getting hit by the same typhoon for the past 5 days. Earlier today, I pulled the kick panel and sure enough found a white 14-pin socket and it was definitely wet. I'm not sure if it's the culprit as it starting raining again and had to close it up.

Top
 

·
Registered
Original owner, 1983 P'up LS (diesel)
Joined
·
2,691 Posts
I'm afraid I'm no help with the electronics involved here. I may be able to help some with the mechanical bits, as they're similar to what's used in the older diesels. We have a few members here who have the 4J diesels. Maybe they'll notice this topic before long.

Jack
 

·
Super Moderator
Joined
·
2,351 Posts
I agree with Joe, sounds like a fuel supply problem. If it consistently will run when primed you most likely have an air leak.

I am quite familiar with the non electronic 4J engines. Your engine is identical, but with an electronically assisted injection pump. I’m not really familiar with those, but I don’t believe there are any sensors. May be wrong though.
 
  • Like
Reactions: JoeIsuzu

·
Registered
Joined
·
9 Posts
Discussion Starter · #12 ·
@mudoilngears Thank u for the advice. If I prime the fuel it will start but dies very shortly after two to three up-down revs while idling. The reason I'm hesitant to believe air leak is if the weather is nice and hasn't rained for a while the Bighorn starts and runs beautifully, no issues. After we get a good rain (again, I'm in the Philippines and it's currently rainy season) is when the problem seems to occur, which is why I'm leaning toward electrical problem. I have found two other Bighorn owners same year and engine 1995, here in the Philippines having the exact same issue. Like me, they have taken to Bosch Diesel Mechanics here (we have the Bosch (ZEXEL) VE series Injection pump) and they haven't been able to figure out the issue either. However, all three of us believed them when they said the pump needed to be rebuilt 😔.
 

·
Super Moderator
Joined
·
2,351 Posts
I can’t see any correlation between priming and an electrical problem. What happens if you continue to pump the primer while it is idling?
 
1 - 15 of 15 Posts
Top