Diagnostic 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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Rjonesy
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Diagnostic Help?

Postby Rjonesy » Fri Oct 26, 2018 6:18 pm

My P'up's been running sweet since a great IP rebuild by Paul and a turbo rebuild. This afternoon running down the freeway there was a sudden loss of power, significant vibration particularly at low RPM, and white smoke. However, oil pressure is normal, temp is normal, no sign of any blow by (checked dip stick, filler cap, radiator overflow, all while running). It starts easy just idles very rough, no acceleration, and billows white smoke.

Any ideas?

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Rjonesy
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Re: Diagnostic Help?

Postby Rjonesy » Fri Oct 26, 2018 6:30 pm

BTW - When the pump was rebuilt I replaced the timing belt and all front end seals as well as manifold gasket. I was super careful aligning and static timing as seen in the nice performance until this issue. Didn't have a tension gauge when installing the belt but felt I had it on the "tight" side.

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Halden
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Re: Diagnostic Help?

Postby Halden » Fri Oct 26, 2018 10:23 pm

Sounds like your timing belt jumped a tooth and the pump is now retarded. Open it up and check. More than happy to snap a pic of the manual so you can get the proper torque for the tensioner bolt. It's set in there pretty tight. Do you have the tensioner spring too?
It's not pronounced "Ih-soo-zoo", it's pronounced "It-screws-you"
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Rjonesy
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Re: Diagnostic Help?

Postby Rjonesy » Fri Oct 26, 2018 10:48 pm

I’ve got a factory manual. That’s my thinking(a skipped tooth). When I replaced the belt I let it ride on the tensioner spring and the tightened it a bit tighter before torquing the tensioner pulls bolt. I torqued everything to specs. I did feel insecure without a tension gauge but thought it was tight enough.

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Paul
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Re: Diagnostic Help?

Postby Paul » Sat Oct 27, 2018 2:50 am

Robert - -

Don't know what is going on but suggest you try to determine what the white smoke smells like. Oil, coolant or fuel? This could help.

And, checking the timing is a good idea.

Paul
'84 P'UP 2 wd diesel, 5 spd with 0.78 fifth gear and differential back to 3.73.

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Re: Diagnostic Help?

Postby 2sk8 » Sat Oct 27, 2018 1:16 pm

Sorry to hear about your trouble.

I agree with the replies above: Sounds like you jumped a tooth.

I would check the timing marks first.

And then if there are fine I would check for air leaks.

When you have air leaks your engine will smoke badly and power will be way down as well.

Clear fuel lines before and after the filter helps a lot to see what's going on.

You can use some 5/16 ID vinyl tubing for the time being (Use VW/Mercedes diesel style fuel clamps if you can, they won't damage the hose and will seat very tight) but if you want to get a better fuel clear hose try this:

MOTION PRO 12-0065 MP CLEAR PVC FUEL LINE,5/16 ID X 3 FT $7.69

https://www.ebay.com/itm/MOTION-PRO-12-0065-MP-CLEAR-PVC-FUEL-LINE-5-16-ID-X-3-FT/192593320059?epid=1822168883&hash=item2cd774d87b:g:-TEAAOSwRuVbQsqt&vxp=mtr

Hope you find a fix soon.

Let us know what was the issue.

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Rjonesy
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Re: Diagnostic Help?

Postby Rjonesy » Sat Oct 27, 2018 9:20 pm

Well - It’s not the timing. Timing was spot on. I noticed a small amount of air in fuel lines (they are clear). Tried changing the filter and doubling fuel line clamps(screw type). After driving there was significant air in line. 2 to 2 1/2 inch bubble at filter output. The primer pump has been “iffy.” Seems to work when full of fuel but will not prime itself (suck up fuel from tank) unless I manually stop output pipe on the recovery stroke. Also in the past I’d noticed some fuel leaking around the pump stem.

Symptoms - very poor idle, lots of white diesel smelling smoke, runs better at high rpms (above 3k) but still lacks power. If it were a gas engine I’d say it feels like it has a “miss” in a cylinder.

Paul - you’ve been inside the pump (I’ve seen your repair posting) just wonder if there is a fixable “o” ring or some type of seal around that stem if I’d do that fix or do I need to look for another filter holder? Assuming that is my actual problem.

The only thing that still causes me to wonder if this is the main issue is that the performance changed fairly suddenly.

Any thoughts?

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Rjonesy
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Re: Diagnostic Help?

Postby Rjonesy » Sat Oct 27, 2018 9:24 pm

Again - there is no sign of a possible head gasket failure other than performance. No mixed fluids, no blow by of any kind, oil pressure and temp are normal.

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Re: Diagnostic Help?

Postby puttputtinpup » Sun Oct 28, 2018 6:38 am

Did you do anything with the injectors? Sojnds to me like one is just squirting raw fuel into its cylinder. That woukd probably affect the pressures and timing of the other injectors. My 2cents

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Rjonesy
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Re: Diagnostic Help?

Postby Rjonesy » Sun Oct 28, 2018 7:27 am

Set pop off over year ago. Nothing since.

dorf
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Re: Diagnostic Help?

Postby dorf » Sun Oct 28, 2018 11:36 am

Just my 2 cents

Air...air...air

Ditch the primer filter pump use a marine primer bulb in series to prime the system


Get substitute primer filter assembly

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Rjonesy
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Re: Diagnostic Help?

Postby Rjonesy » Sun Oct 28, 2018 12:57 pm

Just ordered a Duramax head. Amazon had one same day delivery. I'll put the OEM spec'ed filter on I just got. Was thinking of pulling glow plugs to see if there is any telltale variation in cylinders.

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Paul
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Re: Diagnostic Help?

Postby Paul » Sun Oct 28, 2018 2:14 pm

Rjonesy wrote:
Paul - you’ve been inside the pump (I’ve seen your repair posting) just wonder if there is a fixable “o” ring or some type of seal around that stem if I’d do that fix or do I need to look for another filter holder? Assuming that is my actual problem.

The only thing that still causes me to wonder if this is the main issue is that the performance changed fairly suddenly.

Any thoughts?


Robert - -
The primer pump on the filter head seldom will develop a leak to the outside world. There is no O ring around the shaft as this is not a sealed area. The fuel seal is accomplished with the diaphragm.

I see that you have ordered a new primer pump assembly, so probably no need to worry about the OEM unit.

With your white smoke smelling like fuel, I suggest that you make sure that your intake air supply is properly open and not starving the engine for air. Can't think of anything else just now to cause this sudden loss of performance.

Paul
'84 P'UP 2 wd diesel, 5 spd with 0.78 fifth gear and differential back to 3.73.

dorf
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Re: Diagnostic Help?

Postby dorf » Sun Oct 28, 2018 7:50 pm

I went the duramax route for a while

Found out filtration was too small....can't remember actual number

Eventually clogged.....had to remove....cobbled together an old OEM from parts.....no further problems

Just my 2 cents

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Rjonesy
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Re: Diagnostic Help?

Postby Rjonesy » Mon Oct 29, 2018 2:12 pm

Yes. I was thinking from reading the posts that you could get a 10 micron filter for the duramax head. Now I'm wondering if I was mistaken. Maybe do a rebuild on the original. We'll see.