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Engine Specific Info and Questions => IDI Engine => Topic started by: 3benny3 on April 13, 2017, 12:17:45 pm
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Tore my 1.6TD down to a short block in the car the other day to change a bunch of seals and gaskets but mainly to reseal the pump. As it had started leaking a quick drip. With the pump on the table I resealed most of it, only pulling the head and gov/boost assembly. After putting everything back together when I go to crank it up, it goes straight to wide open (I turn it off right at around 3000rpm, so not sure how far it would go) I believe the problem to be with the gov or throttle? Comparing to pictures of it and others on the internet it appears correct and everything fit ok, but obviously something is wrong. Has anyone else had this problem, or know what I may need to check?
Any help appreciated!
Thanks, Ben
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Good chance the accelerator lever isn't indexed properly on the shaft, or the max fuel screw is in too far, or a combination of both.
Sent from my XT1097 using Tapatalk
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^^^Yup.^^^
Did you mark the accelerator lever to shaft orientation? Did you keep track of how far in the max fuel screw was?
I'd start with turning the max fuel screw out a couple turns. Report back.
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Max fuel screw is the same to a 1/16 a turn, throttle lever was scribbed and put back the except same as well as far as I can tell. Will upload some photos later to see if anything just jumps out as a problem. Thanks for the inputs!
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Rotate the max fuel screw CCW 2 turns and try starting it again. Report back.
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Tried backing it out 3 turns earlier today, but no change. Also moved lever tied into the cold start timing lever on engine head side of pump (name?) to remove tension on the spring pulling lever beside gov (thinking it increases/decreases idle when cold start lever is activated) Will check everything again and do some more testing and report back after work and add the pictures. Thanks
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With the max fuel screw backed out the two turns, pull the accelerator lever off and try running it. If it still over-revs, the issue is internal and something like the control lever assembly not indexed properly with the control collar or the governor spring capsule not attached properly to the control lever assembly, etc...
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Have tried backing out the max fuel, turning the splined throttle shaft clockwise for full idle. Same thing though fires up and off it goes.
Appears that everything is sitting and working correctly, but maybe you can see something that is off? I will do some more testing in the morning, I'm sure it's something stupid simple that I'm just not seeing or am doing backwards.
(http://i64.tinypic.com/rrscux.jpg)
(http://i63.tinypic.com/29m7l74.jpg)
(http://i67.tinypic.com/ibid95.jpg)
(http://i67.tinypic.com/nmx9iu.jpg)
(http://i63.tinypic.com/28kiyav.jpg)
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That all looks right to me. Look down into the diesel while you move the control lever and make sure it is indexed correctly into the control collar and that the control collar moves properly.
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Yep gov lever notch was in the hole in the collar and and moved back and forth on the plunger as the lever was moved back and forth. Will hopefully get to play with it some tonight and in the morning and will report back, really not wanting to pull it again as it's gotta be something dumb but may have to. Thanks again for the insights and pointers
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is the governor assembly /accelerator shaft rotating to the correct side?
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I believe the throttle shaft will only fit one way in the housing. Confirmed for sure that the gov lever is sliding the collar on the plunger freely and is attached via the notch/hole (not off to one side). Also with the max fuel screw all the way out, the throttle all the way closed, and the advance lever all the way off so not to trigger high idle. Crank the car and it still climbs past 3500rpm. Must be something wrong behind the head? Is there something that would cause the throttle/gov system to have no affect?
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The governor/throttle assembly is sitting right on top of a black collar that goes over the governor shaft. Make sure that that piece can move freely back and forth (moving the flyweights with it).
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Ok problem solved, thanks for all the help! Everything was/is correct as far as I can tell. But when installing the top with the boost lever and max fuel screw one or the other or both were interacting incorrectly with the gov lever causing the WOT. This happened installing the top about 4 or 5 times until I was more observant the last time so apparently rather easy to do. You can feel the difference in the throttle shaft with everything back together except for the throttle lever return springs as it is a smoother more pronounced pull against the gov springs and has a bit more travel.Only problem now is a unreliable idle rpm, can set idle but after a rev it may or may not return back as low. Has happened before when the hard lines weren't air free, but will see after some driving.
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Back out the residual fuel screw a hair (the one the accelerator lever rests on at idle) - there may still be a little tension on the transition spring. I've experienced what you are describing with that style of pump before.
Sent from my XT1097 using Tapatalk
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But when installing the top with the boost lever and max fuel screw one or the other or both were interacting incorrectly with the gov lever causing the WOT. This happened installing the top about 4 or 5 times until I was more observant the last time so apparently rather easy to do.
I find that it is best to back the max fuel screw out quite a few turns, then install the top, then screw the max fuel screw back in. That way you are not fighting against it when fitting the top.
As vanbcguy said, your idle issue is most likely the residual pressure screw pushing the lever too far.
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Is that the lever on the top that is connected to the advance lever on the engine side of the pump? Appears to cause high idle with the advance by the spring under the top connected to the gov lever. Would it need to be adjusted to release spring tension or to apply tension then lower idle?
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Your pump has the cold start setup that both advances the timing and increases the idle when the cold start lever is fully pulled. That extra lever on the side is the idle adjustment and has two adjustment screws, one for the normal idle and one for the high idle when the cold start is pulled. That isn't what you should mess with, though, to fix your irregular idle. You should adjust the 'residual pressure' screw which is the screw that the accelerator lever rests on at idle. You should lower it some.
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Ok have adjusted the idle screw (residual pressure screw?) around an inch or more. Have changed the max fuel screw from can't hardly build any boost at all to easily make black smoke when ever I want. Even adjusted the high idle of the advance to hold a higher idle to all the way off. If its idling around 800ish it will come back from a rev, but if I get it up around 1000 where it should be it'll get hung up around 1200 after a small rev or 1800 after a larger rev. Also adjusting idle to 950 where I'd like it is about impossible. Can turn it up from 800 and after several turns out just jumps up over 1000, like a dead spot between. Have tried adjusting the idle with the idle screw and the max fuel screw but seems to have dead spot then jumps up either way. Best way to reach 950 has been to adjust high idle off of the advance.
Noticed some air bubbles in the feed line earlier today but fixed and have noticed no change. Will post video this evening.
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Which screw are you calling the idle screw? There are 4 separate screws on your pump that all affect idle speed and behaviour in one way or another not including the max fuel screw.
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The threaded rod on the top of the pump that changes the lower limit of the throttle arm. Have been looking around the internet for a labeled picture of the adjustment screws, but haven't really found anything useful.
Videos:
https://goo.gl/photos/6DXeB96TsNZYCoUw8
https://goo.gl/photos/M4DB8VjNYMHd3k2s9
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I looked at my prior post and I can see how it is both misleading and incomplete. I apologize for that. I must have been tired.
Here's the routine... set the max fuel, lower the residual pressure so that the idle is stable at the lower 800 rpms, then adjust the main idle screw to set the idle at the appropriate speed, then set the high idle.
You need to set the max fuel first because all idle adjustments are messed up when the max fuel is adjusted. If you have EGT gauge, then I would recommend adjusting the max fuel so that under sustained full load you hit 1200-1250°F. Ignore the idle during this process unless the car is wanting to stall or revs hang, in which case, make a quick and dirty adjustment just to get back to getting the max fuel dialed in.
The threaded rod that the accelerator lever rests on is *not* the 'idle screw'. It is the 'residual pressure screw'. Attempting to use that screw to set your idle is what is causing your problem. It is a little hard to explain... The at-rest position of the accelerator lever needs to be where it is not engaging the intermediate/main springs of the governor capsule. When you see that jump from 800 rpms to an inconsistent 1000+ rpms that is because you are starting to engage the intermediate spring. You need less pressure on the governor spring capsule and then you need to bring the idle up to the desired setting by adjusting the main idle screw. The 'idle screw' for normal operating temp is the screw that the lever on the side of the pump rests against when the cold start is pushed in. The 'high idle screw' is the screw that the same lever rests against when the cold start lever is pulled. Adjust the main idle spring to the desired idle rpm, then adjust the high idle screw with cold start cable pulled. You may need to change the rod length and the adjustment of the two parts of the lever itself to get everything dialed in the way you want it. Let me know if any of that needs further clarification.
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Thank you thank you! What a clear explanation/tutorial. Should be able to get it dialed in first thing in the morning.
Side question; what is a safe EGT temp to run continuous? (Pre turbo sender location) I usually try and stay below 1k never over 1100 very long and pretty much never hit 1200. Use to the Cummins where I pretty much never ever hit 1k, the little VW seems to like to get hotter though. Have the T3 and usually run around 6lbs max normal driving up a hill, 15lbs if I'm trying. Have thought about adding an inner cooler but not sure if its worth the hassel.
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I believe that if measuring pre-turbine with a fast-acting and accurate gauge that 1250°F sustained is fine.
If you're limiting to 15 psi max boost, intercooling would give some gains. If you decide to run more boost than that, you will want to intercool it first. If you're happy with the performance as is, then there's nothing wrong with just driving it.