1980 Rabbit Diesel manual Project

[acidtonic]

Well I tried starting it and nothing blew up. I wasn't able to get it going but I did hear it pop a few times like it was trying. I noticed fuel coming out around the injectors so I tightened them and tried again. Each time after I tried cranking, I pulled the hose off the fuel filter to top it back off with fuel using a funnel since it seemed to not be delivering fuel (no popping). Each time it would take a bit more fuel and some air bubbles would come flying out of the funnel. Then I'd start some more, get one or two pops then no fuel again. I did this a few times before I ran out of time.

After about 5 minutes I noticed another pool of diesel under the car and it seems to be leaking from the return hose on the injectors. I went to pull the hose and tighten it and it crumbled and broke leaving part of it still around the injector. So I'm going to have to get a cheap hose to replace the return lines before I try again.

However it did some quite eager to start when there was fuel. I could get a few combustion events going but not enough to fully start the car though. More to come....

[acidtonic]

Came back after work to find another puddle on the ground. This time it appears to be the fuel return lines that go from injector to injector. I picked up a set on my way to dinner and will install those when I get a chance. Bottom of the fuel pump however is *dry*. W00t.

[TylerDurden]

A couple of things to note:

The IP pumps lots of fuel back out to the tank while using comparatively little for the injectors. This circulation cools and lubricates the IP while it maniacally slaves on top of a 100^oC engine.

You might want to setup a quart bottle of clean fuel with clear lines to and from the IP, to deal with just the pump and not the fuel supply. Once the engine is running off the bottle, you can stop and hook up the filter and tank lines.


At the moment the IP bottom is dry... at operating speeds, the IP case internal pressure can range from 40psi to 150psi.

[acidtonic]

I replaced the lines from injector to injector and the one from the top of the pump to the 1st injector. Still wasn't able to turn it over but it seems the battery is now starting to lose some charge. I left the block heater plugged in for an hour or so and I'm going to run back out and try to start it.....

Otherwise I'll play with it more this weekend... Somehow got stuck with work deliverables this weekend so not much time for fun.

[acidtonic]

A couple of things to note:

The IP pumps lots of fuel back out to the tank while using comparatively little for the injectors. This circulation cools and lubricates the IP while it maniacally slaves on top of a 100^oC engine.

You might want to setup a quart bottle of clean fuel with clear lines to and from the IP, to deal with just the pump and not the fuel supply. Once the engine is running off the bottle, you can stop and hook up the filter and tank lines.


At the moment the IP bottom is dry... at operating speeds, the IP case internal pressure can range from 40psi to 150psi.

Does this still apply if I was just able to start it a few days ago before pulling the pump? I have a gallon fuel tank I bought new to fill up with diesel when priming... could I just pull the cap and dunk the two hoses in that because it's clean? I do not have clear hoses but I plan to get them. Closest place wants $20 for just one hose.


Unrelated but cool side story: I had a neighbor just come over and ask if I could jump start his car. Figured why not, so I drove my truck across the street and jumped him. Then he says he's a mechanic and a collision repair welder...  he immediately started asking about the Rabbit and said he thinks I should pull the fuel filter and pre-fill it with diesel to get it going. Also said he'd help me weld my other car (97 Geo Metro 1.0 3cyl 5pd) which has a rusted out frame horn since I hooked him up tonight. SCORE!

[ORCoaster]

I would use that gallon jug as the base and just get some clear hose from the Home Depot or hardware store to make it work.  No sense buying the expensive stuff for a test project.  But keep the hoses handy as you may find they come into use more than you might care to have them do that.

[ORCoaster]

Tyler:
In your post you mention two pressure numbers

At the moment the IP bottom is dry... at operating speeds, the IP case internal pressure can range from 40psi to 150psi.

I am aware of the lower value at idle but do you have an RPM for the second?  The 150?  I was under the impression that at 75 lbs we would be at full advance on the piston and that the pumps didn't do much more than that.  So I have installed, twice now, a 1-100 psi gauge to my IP.  I have blown both of them and was looking at a 120 psi one for a Christmas present.  Not finding what I wanted I just asked for the one I have for the oil pressure, a 0-150.   I do know that I could bury the IP pressure if I held it in third and took the RPMs up past my usual shift point but I never thought it would be that high.  I recently had a high rev situation on the engine and couldn't get to the key fast enough.  After that I noticed instead of sitting at 43 lbs at idle it was more like 65.  Popped it again, dang it!

[TylerDurden]

Chalk it to poor memory... pressures that high may only be for the 107A pump, others may run 110psi-120psi at ~4000rpm crank.

Mark in the UK and others on the hillbilly board measured some pumps in that lower range, and some bosch/onan test docs seem to be in that range. (7 - 7.6 bar)

[acidtonic]

So any major tricks to priming the pump.... I'm not having any luck. I got it to almost start a few times, firing on about 3 cylinders for maybe 4 solid seconds. Smelled burnt fuel out the rear tail pipe as well. I don't think it's injection pump timing or timing belt issues.... I think simply that this pump isn't primed properly. I sat and held a funnel on the IN hose and gravity fed it for a good 20 minutes and just kept accepting more and more fuel slowly but surely. And by slowly I mean about a teaspoon every 30 seconds then I'd top it back off.

No puddles on the ground except for very very minor dripping from my bleeding. Pump is still dry on the bottom.

I think I just haven't primed it right. I tried sticking both hoses in a gallon of diesel and it still wouldn't fire or run. I think the pump itself is just shot at this point. Or I need to mityvac the out-hose? (I was planning to go buy one tomorrow at harbor freight for $40 and give it a try)

Open to all suggestions

[acidtonic]

Any local places in Michigan that have something like a cheap electric diesel fuel inline pump? I think that would solve this issue but I don't feel like waiting weeks on shipping.

[TylerDurden]

I'd get the mighty-vac (or the knockoff). It's diesel basics to get the IP full before cranking. 

If you don't see circulation from the container and back during cranking with the IP full, the inline pump might help. Or, you could hang the supply container higher and a collection container lower.

[TylerDurden]

PS:

The IP will fill slowly via gravity if not cranking, the opening in the OUT bolt is only .55mm.

When running, the flow from the OUT bolt is around a quart a minute.

[acidtonic]

Got a Mityvac so today I'll give it a shot when I'm home from work. Also ordered a Mr Gasket Diesel inline electric pump which should arrive in the mail in a few days.

[acidtonic]

I ran the pump on the OUT line and pulled until I saw fuel, then after some more vacuum I saw a bunch of bubbles come through which turned to very very small bubbles. Tried to start the car and no difference. However after this time I noticed a big white cloud of smoke behind the car.

I'm starting to question if I installed the pump at the wrong timing or something at this point. When I was cleaning it the main shaft might have rotated a bit, I'm now curious if it's possible to be 180* out or something strange. I may end up retiming the pump just to be sure. My gut says the pump timing is incorrect but we'll see.....

[nissannx]

It's very easy to be 180 out. At this point that what it looks like if you have white cloud and no start