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Engine Specific Info and Questions => IDI Engine => Topic started by: Syncroincity on August 21, 2015, 05:20:20 am
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OK, this is a weird one.
Background; Engine was running fine, no issues. Turbo oil line broke, had to get a flatbed ride home.
After I replaced the oil line, took it out for a drive.
Seemed normal, until it reached operating temperature.
At that point, whenever I accelerated up to about 3200 rpm, the fuel seemed to cut off. Completely. It was like hitting a brick wall.
The fuel simply shut off, and will remain shut off until 1. I let off the pedal completely and 2. it drops back below 3200 rpm.
I changed the fuel filter, thinking the flatbed ramp had stirred up sediment or something, but it's the same.
It does NOT do this when the engine is cold.
It happens regardless of throttle position, even holding the pedal steady, if I go down a hill and the van drifts up in speed, the fuel cuts at the same point. Full throttle or cruise or slack throttle, same results.
Power output seems to be the same as before. Pulls like a freight train, until it doesn't, and everyone's head snaps forward and they look at me like I'm a dick doing it on purpose... :-*
It is also suddenly difficult to start, even on a hot day without plugs and cold start, and stutters and smokes white like it's below zero out.
At this point I'm thinking the pump jumped time somehow... maybe the governor is kicking in? It used to rev freely, this came on all of a sudden, after a non-fuel repair. WTF?? ???
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Think the towing company could have pinched a line putting it on the flatbed?
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I would definitely double-check the timing.
Does the change occur when the engine warms up or perhaps when the cold start lever is pushed back?
You may have already, but I would also recommend that you pose your question directly to Giles.
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My money is on the turbo bearing. The turbo gets hot and runs slightly erratic on boost.
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your manifold doesnt have one of those overboost safety valves does it?
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No safety valve.
I actually drove it up onto the flatbed... which is why I thought the fuel filter may have been blocked, it was pretty steep.
I don't think it's turbo related... when the power cuts off, so does the exhaust smoke. When I had issues with a boost hose popping off, the smoke tripled when it lost boost pressure, this thing is cutting the fuel. It's got to be the governor.
I'll check the timing this weekend, it must have jumped a tooth or two, the cold-start issue points to that pretty hard.
I'm just having a hard time with the operating temp part of the equation. Cold-start lever position does not seem to affect when this occurs, in or out it does not happen until the engine gets good and warm.
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If the timing jumped that would make sense as it could be hitting full advance even though you are at 3,200rpm. Giles doesn't shim the spring, he adds another from what I have seen, so I really doubt that the spring broke, but that could explain the symptoms as well.
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I read a discussion on the samba of, I think, a subaru vanagon skipping timing after a flat bed tow. The van was in gear and, it's believed, not properly secured, so it rocked back and forth putting stress on the belt. It sounds awfully weird to me, but apparently this was an issue known to subaru, for which they made some minor modification to the timing belt setup.
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I'd be investigating the crank nose if the timing is off. The TDI mod is not bullet proof (assuming you've done that...)
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Yup I also think the pump timing is off. Is it possible it rolled off the flatbed in gear and rolled the engine backwards and forcing the belt to skip
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Is your pump using a cable on the mechanical cut off lever or is it electrical?
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Great points, it was getting bounced around pretty violently during the ride home. :P
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I dont know if this helps but tonight i was messingnwith the settings on my pump and the idle adjust rod at the back fell apart. After i put it all back together its been doing the same thing. I still have no clue whats going on though.
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I just moved the fuel pump back towards the engine, everything operates normally now, no cut-off of fuel. I need to adjust it a little back towards retard because the motor is quite loud in idle now, similar to how it sounded when I first fired it up a few years ago. Sounds fine while driving but at idle and low-power accel it gets quite rattly.