Fuel pump help

The place to discuss problems and routine maintenance questions and tips. This is for topics that are specifically diesel-related.
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Skropeling
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Location: Mimbres, NM
Isuzu vehicle(s): P'up

Fuel pump help

Postby Skropeling » Fri Jul 20, 2018 4:14 pm

So my Pup had been at the mechanics for over a month now, and they say they've finally nailed down the fuel pump as being the issue. They say that it's not even close to making the pressure needed to operate the injectors properly. So issue found, all is good right? Well, they say that the only fuel pump they can find will set me back around $2000. Double what I Paid for the truck, so that's not an option. They also said that rebuilding it is a possibility, but hey couldn't find anyone to do it. Any Ideas? If I can't fix the current pump or find a new one, I'll probably have to give up on my Pup, which is something I don't want to do. Thanks.

dorf
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Re: Fuel pump help

Postby dorf » Fri Jul 20, 2018 4:48 pm

It is obvious that they are over their head

There is a member on this board...Paul....that overhauls the complete injection pump assembly ,,,for somewhere around 400 dollars or so...but...but

I'm guessing your problem is air....air.....air in the supply and delivery fuel lines

Those pumps suck and then deliver fuel to the injectors......if they suck air instead of fuel...nothing happens

Troubleshoot it your self...get a new mechanic...tow it to a real diesel shop

Just my 2 cents

dorf
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Re: Fuel pump help

Postby dorf » Fri Jul 20, 2018 5:01 pm

Continued from above

Removing the injection pump and then re installing and timing is a whole other issue....if and when you half to do it...replace the timing belt, the water pump and the small water hose up front

Again....just my 2 cents...good luck.....but I'll bet your problem is air

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JoeIsuzu
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Isuzu vehicle(s): Original owner, '83 LS Diesel, 5-spd, 2wd, Long Bed, restoration in progress!

Re: Fuel pump help

Postby JoeIsuzu » Fri Jul 20, 2018 5:01 pm

Yeah, what he said! ^ ^ ^ ^ ^ ^

Jack

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puttputtinpup
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Re: Fuel pump help

Postby puttputtinpup » Sat Jul 21, 2018 2:57 am

Dittos.

FiatSpider2
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Re: Fuel pump help

Postby FiatSpider2 » Mon Jul 23, 2018 8:38 am

Verify the fuel lines are good, clamps are snug but not so tight that they are cutting the hoses and ensure that the screen inside the banjo on the inlet of the IP is clean. If you did not already install a new fuel filter then do that too and be sure to fill it with Dexron I or II ATF before reinstalling it. The Dexron will clean and lubricate the pump and the seals inside it. Mine has well over 250,000 miles on it closing in on the half million mark and as far as I know its the original Kiki IP.

Most folks will probably find that servicing the fuel lines, clamps, screen and fuel filter (don't forget to fill it with Dexron I or II) usually resolves the majority of problems that some mechanics try to get you to buy a new IP for.

A few weeks ago I was helping someone with a fairly new diesel that they though had a really bad IP problem and they were amazed at how it ran just 5 minutes after draining the fuel filter, filing it with Dexron, starting it up and letting it run at a fast idle for a few minutes. They wanted to know what I fixed or adjusted and all I did was treat the fuel filter with Dexron ATF and start it up. They have now added filling the fuel filter with Dexron I or II to their oil change schedule.

Look at is as Dotting your I's and Crossing your T's before committing to the extreme of replacing or rebuilding the pump. Yes if rebuilding is really required afterwards it can be done for around $500 by sending the IP to the member here that specializes in that service who is a pro working in an IP Shop and not just a Shade Tree guy doing it in his back yard.
FiatSpider2 (4FB1 Isuzu Diesel powered 1978 Fiat Spider)

2sk8
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Isuzu vehicle(s): 91 Isuzu Pick up converted to diesel

Re: Fuel pump help

Postby 2sk8 » Mon Jul 23, 2018 11:48 am

And don't forget to check that the fuel priming pump is working as it should: Keeping the prime to the injection pump.

The priming pumps do fail and no matter what you do the injection pump will no keep its prime.

The hand priming pump is what is on top the filter.

One easy way to check is to install a clear line (You can use a 5/16 vinyl tube for the time being) from the outlet of the priming pump to the injection pump.

You will see right away if you have air problems.

I have all my important fuel lines (In and out of the injection pump) in clear fuel hose, having clear fuel lines makes troubleshooting for problems so much easier, you will see right away is air is your problem.

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DieselJeep
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Re: Fuel pump help

Postby DieselJeep » Tue Jul 24, 2018 8:34 am

I concur with all previous posts.
I wanted to add, on ebay the polyurethane 5/16 hose is diesel impervious, and like $20 for 20ft. I have only a steel line down the frame rail. Between the tank puckup and my aftermarket lift pump, filter, to hard line is poly. Then, from hard line to filter/water separator/primer, to IP is all poly. Easy to see air if it occurs. Don't bother with worm clamps, even doubled, clocked 180*, on hoses. I could never get them to seal. No luck with "fuel injections" style worm clamps either. I use the spring clamps, for full 360* clamping. Or you can buy VW style, one use only crimp style clamps, but those aren't at hardware and local parts stores in stock.
Unskilled, uneducated, inexperienced, tools/facilities lacking, and faint of heart, be warned:
All vehicles are hunks of crap. Designed by individuals, the majority of which, have never turned a wrench.
Which one do you want to fall in love with?

FiatSpider2
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Re: Fuel pump help

Postby FiatSpider2 » Wed Jul 25, 2018 9:21 am

On mine I added a MrGasket/Mallory lift pump to handle the priming and have it triggered by the fuel valve circuit. No manual pumping and it runs every time I turn the ignition key to the on position.
FiatSpider2 (4FB1 Isuzu Diesel powered 1978 Fiat Spider)


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