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81 Rabbit IP Problem
Posted: Tue Jun 10, 2014 3:20 pm
by uzzo2
Hi guys, still working on this rabbit I bought a while back. The IP started leaking so I called the guy that resealed the one on my golf several years ago. I'd have to ship it to him and he said he wouldn't be able to get to it until friday. I thought to myself dang, I need this thing. I'll just take the pump off of the 86 golf and put it on the rabbit.
I just got done with it and it just isn't acting right. I did the timing like the Bentley manual says. But it does pretty good at idle and low RPM's. But once you get up to speed and higher RPM's. It starts stalling out is probably the best way to explain it. Once it gets to a certain RPM, that's it. It just quits pulling. The only thing I can think of is that I probably committed the ultimate sin when I forgot to put some caps over the injectors while I was working. I sprayed some carb cleaner in each of them to clean any trash out. But, who knows? I've tried playing with the timing on the pump to no avail. Anyone got any other suggestions?
Re: 81 Rabbit IP Problem
Posted: Tue Jun 10, 2014 5:04 pm
by Fatmobile
Max fuel screw turned in far enough?
Accel lever goes all the way to the max RPM stop when floored?
Clear fuel lines? No air?
What color smoke if any?
Re: 81 Rabbit IP Problem
Posted: Tue Jun 10, 2014 5:29 pm
by uzzo2
Fatmobile wrote:Max fuel screw turned in far enough?
Accel lever goes all the way to the max RPM stop when floored?
Clear fuel lines? No air?
What color smoke if any?
I don't know about the max fuel screw Fat. I've never fooled with one, don't even know which one it is to be honest with you. I did check to make sure it's getting full throttle when the pedal is depressed. Although the little rubber grommet where the cable hooks to the pedal is gone and it's fallen out a couple of times. The fuel lines aren't clear anymore, so I don't know if it's getting any air. Actually, the only one that was clear is the one from the filter housing to the IP. The return line is black. It's blowing lots of white smoke. I can pull the cold start out and that will clear up. But I still have the same problem as far as power goes. It worked fine when it was in the golf as well as the pump I took out. Only, the one I took out was leaking. I'm leaning towards an injector because when it's cold it sounds like it has a sight skip to it.
Re: 81 Rabbit IP Problem
Posted: Tue Jun 10, 2014 6:23 pm
by 82vdub
White smoke is poor combustion. Since you changed nothing but the pump, it's either the pump, or timing. If the pump is known to be good (like from a running car), advance the IP timing by rotating it towards the head. It's probably pretty retarded, timing that is.....
Re: 81 Rabbit IP Problem
Posted: Tue Jun 10, 2014 7:51 pm
by uzzo2
82vdub wrote:White smoke is poor combustion. Since you changed nothing but the pump, it's either the pump, or timing. If the pump is known to be good (like from a running car), advance the IP timing by rotating it towards the head. It's probably pretty retarded, timing that is.....
I think the mechanic that's working on it is pretty retarded 82! I tried that, I had it so rich that it wouldn't even idle. I just kept playing with it, moving it back a little at the time. Once it's good and hot. It'll idle just fine, but when you try and drive it, it just stalls when you hit a certain RPM. The only way I can explain it is like driving a governed big truck. Once you hit the predetermined limit, that's it, no more fuel. I can grab another gear and it picks up just fine until you get into higher RPM's.
Re: 81 Rabbit IP Problem
Posted: Wed Jun 11, 2014 3:45 pm
by uzzo2
Just wanted to give a quick update. I just got finished swapping out the fuel lines with nice new clear ones. No bubbles from the filter housing to the pump. Lots of bubbles from the pump to the return line. Is that normal?
Re: 81 Rabbit IP Problem
Posted: Thu Jun 12, 2014 8:52 am
by Quantum-man
uzzo2 wrote:Just wanted to give a quick update. I just got finished swapping out the fuel lines with nice new clear ones. No bubbles from the filter housing to the pump. Lots of bubbles from the pump to the return line. Is that normal?
Bubbles may be from pump pulley drive bush. Often accompanied with hard starting when left for a while as pump needs to reprime.
Bubbles could also be coming from injectors' leak offs. A transparent line there will reveal that.
Poorly sealing heat-shields cause this as they allow pressure from the cylinder to form between the injector body and the nozzle.
Remember the shield has 2 sealing surfaces, and often don't seal perfectly, but it goes unnoticed if problem is minor, and injector outer is dry.
Get a spillage from leak-offs, body halves, or fuel supply lines, and the leaks miraculously appear.
Bubbles can actually form from the rapid decompression of the diesel as it leaves the pump.
Re: 81 Rabbit IP Problem
Posted: Thu Jun 12, 2014 1:57 pm
by uzzo2
Quantum-man wrote:uzzo2 wrote:Just wanted to give a quick update. I just got finished swapping out the fuel lines with nice new clear ones. No bubbles from the filter housing to the pump. Lots of bubbles from the pump to the return line. Is that normal?
Bubbles may be from pump pulley drive bush. Often accompanied with hard starting when left for a while as pump needs to reprime.
Bubbles could also be coming from injectors' leak offs. A transparent line there will reveal that.
Poorly sealing heat-shields cause this as they allow pressure from the cylinder to form between the injector body and the nozzle.
Remember the shield has 2 sealing surfaces, and often don't seal perfectly, but it goes unnoticed if problem is minor, and injector outer is dry.
Get a spillage from leak-offs, body halves, or fuel supply lines, and the leaks miraculously appear.
Bubbles can actually form from the rapid decompression of the diesel as it leaves the pump.
I did notice while I was cracking each injector line to see if it was an injector yesterday. The fuel gathering at the bottom of a couple of them were bubbling. So there's some leakage there. I just don't really know where to start other than from the beginning. Recheck the timing and then pull all the injectors out of my golf and put them in the rabbit. It's just got me scratching my head. There were no bubbles in the supply line from the filter housing. Only in the return line. Does that cause a priming loss issue if it's in the return line?
Re: 81 Rabbit IP Problem
Posted: Thu Jun 12, 2014 2:25 pm
by 82vdub
Did the replacement pump come from a working, and recently working, engine? Or was it pulled from something that's been sitting for years? That's important information.
Re: 81 Rabbit IP Problem
Posted: Thu Jun 12, 2014 2:31 pm
by Quantum-man
uzzo2 wrote:
I did notice while I was cracking each injector line to see if it was an injector yesterday. The fuel gathering at the bottom of a couple of them were bubbling. So there's some leakage there. I just don't really know where to start other than from the beginning. Recheck the timing and then pull all the injectors out of my golf and put them in the rabbit. It's just got me scratching my head. There were no bubbles in the supply line from the filter housing. Only in the return line. Does that cause a priming loss issue if it's in the return line?
Not directly because the return line is open at the tank end.
Fuel held there by good sealing on the leak-off lines and the mass of diesel in the pump...
I believe there is some stuck in the return to the tank, because today when I removed the plugged leak-off line,
with the engine off, the fuel in those little lines which are transparent on mine,
shot along the row of injectors and uphill into the banjo and back to the tank.
This would only happen if there was a quantity still in the main return due to that 'hill'
Re: 81 Rabbit IP Problem
Posted: Thu Jun 12, 2014 5:30 pm
by uzzo2
You guys aren't going to believe this. I must have went on full auto retard when I was putting this thing back together. I decided when I went back out intending on swapping injectors and God knows what else. I thought to myself, maybe I ought to start with making sure there's no restriction in the banjo fittings. I got to looking at them real close before I took them off. The one marked out was on the inlet and vice-versa. I swapped them out and voila, she runs like a raped ape now!
Re: 81 Rabbit IP Problem
Posted: Thu Jun 12, 2014 5:33 pm
by 82vdub
That's an easy item to miss and nice that you figured that out. Restricted fuel will let an engine run like it just can't get enough fuel.
Re: 81 Rabbit IP Problem
Posted: Thu Jun 12, 2014 5:44 pm
by uzzo2
82vdub wrote:That's an easy item to miss and nice that you figured that out. Restricted fuel will let an engine run like it just can't get enough fuel.
Well, I'm just very appreciative for guys like all of you here that help out all of us who may or may not be mechanically inclined and don't have a clue about these cars. I used to be a pretty good diesel (truck) mechanic. But these little v-dubs are a different kind of beast. Now I have to get the money up so I can get the motor out of my golf and get it to Jack to build. So I'll be starting all over again hopefully in the fall. I emailed him a couple of months ago about it. He didn't have any cores at that time. I sure hope that changes by fall, it'll make life a whole lot easier for me.
Re: 81 Rabbit IP Problem
Posted: Thu Jun 12, 2014 9:02 pm
by 82vdub
I am continually amazed at the experience that several posters on this site have on these cars. Some information just boggles the mind on how someone figured some of the stuff out.
Re: 81 Rabbit IP Problem
Posted: Thu Jun 12, 2014 9:20 pm
by uzzo2
82vdub wrote:I am continually amazed at the experience that several posters on this site have on these cars. Some information just boggles the mind on how someone figured some of the stuff out.
Me too 82, I scoured the net last night looking for the same symptoms that I had as well as this forum. I've had trouble going to sleep the last couple of nights trying to go over in my mind what I may have done wrong. And I just couldn't come up with anything. As a general rule I am very meticulous about everything I do because I don't like making mistakes. So this thread is a good thing IMHO. It may help someone else that is having the same problem after replacing an IP. Many thanks to you and Fat, Hagar, Vince Waldon, Quantum, bscutt and all the rest here that have contributed. These forums are one of the best resources for information in the entire world as far as I'm concerned.