Hard to Start then Runs Fine
Hard to Start then Runs Fine
Hello all! Have an 86 TD 2.2 pup that has become hard to start. Recently had new injection pump in. It runs great once it gets going, but I really have to push down on the fuel pedal for a long time before it seems to get enough fuel to cold start, especially if it's been sitting for a few days. What could the issue be? I've replaced the glow plugs with no change in performance.
New owner, '86 Isuzu P'Up Turbo Diesel SpaceCab, 5-spd, 2wd
- JoeIsuzu
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Re: Hard to Start then Runs Fine
Tell us about your fuel lines. New, or old?
Sounds like classic air leak symptoms.
Jack
Sounds like classic air leak symptoms.
Jack
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- spideypop
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Re: Hard to Start then Runs Fine
My thoughts too. Especially since you had a recent injection pump change.
- puttputtinpup
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Re: Hard to Start then Runs Fine
I had the same issue with my 84 automatic after I disturbed the original fuel lines. The return line in particular was leaking air. I replaced them all and problem solved. You'll need to get different hose clamps.
Re: Hard to Start then Runs Fine
Is there a lot of smoke when it finally starts? If so, it is probably not a fuel problem but more likely a faulty glow system.
New glow plugs may not mean that they are working right or at all. See if you can get a clamp on current meter to watch the glow current while some one else does the glowing. You should see 140 amps initially, followed by a smooth decline to 40 amps over a period of about 4 seconds.
Failing the current meter, glow until the glow lamp goes off and then feel the current sensor part of the glow bus bar (be careful to not burn your fingers). The sensor should be hot, maybe too hot to touch.
Also, there is the tried and true method of watching the cabin lamp to see if it goes dim while glowing. Not definitive quantity wise but still useful.
Paul
New glow plugs may not mean that they are working right or at all. See if you can get a clamp on current meter to watch the glow current while some one else does the glowing. You should see 140 amps initially, followed by a smooth decline to 40 amps over a period of about 4 seconds.
Failing the current meter, glow until the glow lamp goes off and then feel the current sensor part of the glow bus bar (be careful to not burn your fingers). The sensor should be hot, maybe too hot to touch.
Also, there is the tried and true method of watching the cabin lamp to see if it goes dim while glowing. Not definitive quantity wise but still useful.
Paul
'84 P'UP 2 wd diesel, 5 spd with 0.78 fifth gear and differential back to 3.73.
Re: Hard to Start then Runs Fine
Hi Paul,
Yes, lots and lots of smoke. This sounds like what I might have. I am going to try to start it up this week and test it with a meter. What I do attach the clamp meter to?
Yes, lots and lots of smoke. This sounds like what I might have. I am going to try to start it up this week and test it with a meter. What I do attach the clamp meter to?
New owner, '86 Isuzu P'Up Turbo Diesel SpaceCab, 5-spd, 2wd
Re: Hard to Start then Runs Fine
They're the originals... if it is a fuel line issue, how do I go about fixing it -- do I need to replace the fuel lines or is it possible they can they be repaired (looks like a hard repair, such small delicate lines? Would I have to find the lines off another truck?
New owner, '86 Isuzu P'Up Turbo Diesel SpaceCab, 5-spd, 2wd
- Duck
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Re: Hard to Start then Runs Fine
They're the originals... if it is a fuel line issue, how do I go about fixing it -- do I need to replace the fuel lines or is it possible they can they be repaired (looks like a hard repair, such small delicate lines? Would I have to find the lines off another truck?
[/quote]
Not the steel lines, Just the rubber ones.
[/quote]
Not the steel lines, Just the rubber ones.
90 Dakota with C223
- JoeIsuzu
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Re: Hard to Start then Runs Fine
Well I didn't ask enough questions before weighing in. 
Jack

Jack
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Re: Hard to Start then Runs Fine
I'm confused......just replace all rubber hoses and use screw type clamps and use Barricade rubber fuel lines. Easy but important fix....for a happy engine.
Don't mess wth the metal fuel lines.
Don't mess wth the metal fuel lines.
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Re: Hard to Start then Runs Fine
On those rubber line replacements, make sure you replace the smaller diameter line on the return side too. I had a crazy time once after I replaced all the delivery lines, only to be thwarted by that little one. Also dont try to cheat a too large diameter with a clamp, that also funked me once.
1982 2x4 Diesel Pup Two Tank WVO System
1981 2x4 Diesel Pup DLX Long Bed
1986 4x4 Turbo Diesel Pup Space Cab
1981 2x4 Diesel Pup DLX Long Bed
1986 4x4 Turbo Diesel Pup Space Cab
- Siegfried
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Re: Hard to Start then Runs Fine
I've also had a little trouble starting, at least when it's cold, and after reading this I thought I'd replace my fuel lines since they are old, just in case it might help.
When you replace these hoses do you have to do anything special to bleed the air out of the diesel fuel system or can you just replace them and start it up?
When you replace these hoses do you have to do anything special to bleed the air out of the diesel fuel system or can you just replace them and start it up?
1985 Isuzu P'UP Diesel Long Bed
- JoeIsuzu
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Re: Hard to Start then Runs Fine
We need to stay with BravoDrew's issue here, so I'll be brief:Siegfried wrote: ↑Sat Dec 03, 2022 9:41 amI've also had a little trouble starting, at least when it's cold, and after reading this I thought I'd replace my fuel lines since they are old, just in case it might help.
When you replace these hoses do you have to do anything special to bleed the air out of the diesel fuel system or can you just replace them and start it up?
Supply lines will require bleeding.
Return lines will not.
Jack
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Re: Hard to Start then Runs Fine
Bravodrew I feel your pain.
I had my voltage to the plugs and still got the smoke. I wasn’t getting fuel until the plugs cooled some causing the smoke.
Just for information check O Ring on butterfly drain on top of water separator. I was sucking air there. New Truck now. Mike
I had my voltage to the plugs and still got the smoke. I wasn’t getting fuel until the plugs cooled some causing the smoke.
Just for information check O Ring on butterfly drain on top of water separator. I was sucking air there. New Truck now. Mike
83 DLX 4x4 diesel pup
86 turbo space cab Ls pup
Cummins 3500 4X4 6 speed Manual
2011 Limited Ultra HD
86 turbo space cab Ls pup
Cummins 3500 4X4 6 speed Manual
2011 Limited Ultra HD