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General Information => General => Topic started by: iamdieselnutmechanic on July 18, 2014, 01:37:39 pm
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So every start after the car has sat and is thus not operating temperature, the idle is funky.
It will start and chug away at a low idle, and then as it warms up you can hear and feel the idle pick up like 250rpms and smooth right out. All at once too, not gradually. Chugging, to running right in quarter second.
So I am kind of at a loss. Does it need more residual fuel screw and less max fuel? So that the governor sprimgs have more action?
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Needs injectors cleaned.
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Guess I should have added this is a mechanically pumped 1.9 tdi.
Injectors, like the nozzle/tips you mean
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Yes nozzles, Have you any idea on what your compression in each cylinder is both cold and hot. It might be that the heat expands the rings that are worn to be able to seat better and compression gets much better and fuel burns and RPMs jump.
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It could be as simple as air getting in.
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Cold compression (0c 32f out lolol) was 400-415 across the board when I checked it this past winter..
Hmm. I do actually have a slight fuel drain back issue that I cannot pin point, thank the lord for the electric fuel pump in line. Even if I let it pump and fully fill up it still does it. But I think you might be on o something Burn_your_money.
Have you ever seen this with the settings? Or am I chasing nothing on that front??
In the winter, or for the first start of EVERYday I need to be in the car with my foot on the pedal to start it.
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The Normal start process outlined on the visor above my head advises to press lightly on the accelerator at all times when starting. 1/4 press. How else do you get it to go VAROOM and get the Alternator light to go out.
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ahh the beauty of the serpentine alternators! no need for the gratuitous throttle rev to start charging.
Even if I did that, it would chug to life no problem rev up and then drop to an ungodly low rpm where it is just CHUGCHUGCHUG along.
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Usually the high spin up gets rid of any air in the pump. You sure you don't have air sneaking in someplace. The chug a lug description makes me think that is what you have going. Air in Fuel filter? Need a piece of clear line on the out to the tank to see this. You might have a bad seal on the pump too. Air can come in from a dozen different sources on these things and it affects idle the most. I see it alot when I flip from WVO from diesel if I haven't used it in awhile. Takes to long to fill the filter and the engine craps out or if I am quick on the switch and add diesel every so often I can pull fuel along and eventually get a solid flow going.
Keep looking.
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Interesting.. all new seals in the pump! I had a pump failure on a long long road trip far from home and had the good luck to get towed to a Bosch specialist who let me use his shop to fix my pump for free. New seals, and a few new pieces the pump ate. I am not ruling out the seals definitely, but they should be good.
New filter along the way too. I picked up some bad fuel, and changed out on the side of the highway. I will check the lines back near the tank, and replace the little rubber ones between the injectors for shiggles. I have re-cut the ends of the clear one on my filter-to-pump line but i do not have a clear line after the pump back to the hard line. I will get either a clear line on there, or some sort of viewing glass.
Oh another thing, sometimes if the alternator load is high enough.. Like if I wanted to afterglow my plugs.. it will bring the idle down to the same chug a lug, which is what pointed me to the settings of the fuel screw and the governor springs..
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I will ask.....
What did you do for tdi-m pump??
Cam plate in rover 200 pretty steep vs 300.... The timming adv mech in the 300 is really really odd.... Vs say every thing else... Well 1.6-aaz pumps at least.... The 200 is more like aaz but still little different... I aassume this is due to lack of mechanical adv... You sure they look to use fuel pressure to dampen or manipulate it..
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This is a 300 body, lid, governor assembly, governor cage and 11mm head/plunger.
With 98 AHU rollers, camdisk and plunger springs. As well as the AHU advance piston, spring, front timing cover and the AHU pressure relief valve. I figured it would be a good idea to use the 1.9's pressure relief and timing advance piston to properly match what this engine needs in terms of mech adv.
I have 1.6 delivery valves in the head to be the proper length for my fuel lines. The AHU ones I lost a piece of one when I had it apart, or I would be using them.. :(
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Id put 300 adv mech back in.... Tdi-e has electric valve to assist its mechanism... Controls fuel flow to it... Rover one made to adv timming and stuff when cold... You eliminated it :-*
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Also... I use them stock, with idi out bolt... No fuel pressure issues i know of... And the 300 is smooth down to say freezing when cold...
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I saw your other thread there with the pump stuff, my 300 advance didn't look like yours. Mine was a single small spring. much like the 1.6 pumps.
I don't see how the rover spring and piston could somehow add cold advance?
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I had a similar issue with one of my mtdi pumps. I narrowed it down to the number 3 high pressure line draining slightly. See if you can narrow down which cylinder isn't firing on start up by putting your hand on the exhaust manifold. The exhaust manifold will heat up the slowest near the cylinder not firing. As long as you're careful you won't burn yourself. It heats up at a fairly slow pace and diesels don't produce that much heat at idle.
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I am not sure it is a not firing issue, but i will check that. :)
Its definitely weird.. I'll get a video/soundclip of a start and idle.
What is acceptable idle? Cause it seems to me, anything below 1000 is where it has issues.
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I am not sure it is a not firing issue, but i will check that. :)
Its definitely weird.. I'll get a video/soundclip of a start and idle.
What is acceptable idle? Cause it seems to me, anything below 1000 is where it has issues.
If it has a hard time idling under 1000 rpm, you might be out of the working range of the governor flyweight assembly in the pump. A couple things can affect this. You can try installing a thinner button shim that goes between the rotor and the camplate but going this route means resetting most of the pump settings and you have to take the head of the pump off to get to it. Or you can add a shim behind the governor flyweight assembly to move the whole assembly towards the governor lever. This is much easier to try since it can be done from the top of the pump and it doesn't take much of a shim.
The other item to look at to deal with a rough idle is the idle spring on the caged governor spring assembly. A lighter spring might help smooth the idle out a bit.