T4 1.9 TD ABL idles too fast

[joe peat]

HI Everyone.
This forum seems brilliant. Just what I've been looking for!! Anyway I've been searching around here for a week or so but can't find the answer to my problem.

I recently changed the main seal in my VE pump whilst leaving the pump on the van to preserve timing. It actually turned out to just be the o-ring on the plug where you screw in the depth guage that was leaking but that's not important anymore

Having put it all back together I can't get the idle speed below 1010 rpm.

I've checked the cold start is disengaging properly, think it is. It's certainly turning the cam on the pump (I've also managed to completely wind out the idle screw from the lower cold start pivot so will have work out how to put that back in somehow).
I've wound back the stop for the normal idle adjustment,
wound the max fuel screw out (that lowered the revs but made the van undriveable, I'd imagine due to lack of fuel.

I've also checked then position of the throttle spindle and checked the residual fuel spring inside the top cover of the pump. All looks Ok. Also the van drives fine. I just can't get it idling like it did before at around 850rpm.

Any help or pointers from you guys would be hugely appreciated. I am just running as is but really want to get it running properly before any long journeys.

Thanks in advance.
Joe

[fatmobile]

 Does this pump have the rod going down to the cold start lever in the back of the pump?

[joe peat]

Yes, I think that's the screw I inadvertently backed all the way out today. It actuates the cam on the top cover?

I'll try and post a picture

[joe peat]

I've changed my profile pic to the type of VE pump I have. One of these.


Fuel Injection Pump 0460494356 VW T4 1.9 TD ABL 50kw 028130109N 028130110B

Cheers
Joe

[libbydiesel]

Red arrow points at the vertically oriented 'high idle' screw.  That is the idle setting when the cold start lever is pulled.

Yellow arrow points to the vertically oriented 'slow idle' screw.  That sets the idle when the cold start lever is pushed in. 

The green arrow points to the head of the screw that sets the relationship between the rod and that lever assembly.  You can also adjust the length of the rod. 

[ORCoaster]

Ohh man you have a perfect sense of timing sir.  I was fighting with the idle on the turbo 1.6 in my pickup this weekend and I was going to spend some time trying to figure out the screws and the lever.  Now I have a picture and everything.   Whoo-hoo.  printing this and sliding it in the Bentley for safekeeping. 

I thought I had the idle set, OK but after driving it to work the last couple of mornings I think I need to come down a few hundred and up the RPM on the pulled-out cable side of the rocker.  I wanted a higher idle when cold not all the time.

[joe peat]

Thanks for the replies.
So that is the problem. Even adjusting the yellow screw right out and extending the rod as far as it will go. The idle will not drop below around 1050. 

[libbydiesel]

Is the back part of the lever (the part that is not connected to the rod) resting against the casting?  If not, then you still have adjustment left with the green.

If the idle screw is not having an effect on idle, then there is some possibility that either the accelerator lever to shaft orientation needs to be jumped one spline and/or the "residual pressure screw" (horizontal all-thread rod directly behind the yellow arrow that the accel lever rests on at idle) needs to be unscrewed some.

[joe peat]

yes I've tried the lever right up touching the case with very little effect. Also i think I can turn the throttle spindle as far down as I like but still the rpm won't drop below 1050. I'll double check all that in the morning. Thanks again

[libbydiesel]

If the idle is still too high with the accelerator lever removed and the side lever touching the casting, then you have run out of fueling potential with your pump and your max fuel is turned up too high. 

[joe peat]

Hmm, ok. when I turned down the max fuel screw so the idle was set to the correct rpm I couldn't rev it hardly with the accelerator and it wouldn't start again after I switched it off.

I wonder if I have connected the spring inside that attaches the lever on the top cover to the internal lever wrongly and the idle is stuck on the cold start setting internally?

[libbydiesel]

What is the history of the pump?  What have you done to it?  Be specific.  I have been basing my responses on the assumption that the pump was assembled correctly.  If not, then all bets are off.

If the idle spring is connected in a manner that puts extra tension on the spring, then it might behave in the way you describe.   

[ORCoaster]

JP  Take a look at the picture Libby so grandly provided.  See the threaded rod with the nut on it that runs behind the yellow arrow and touches the lever stop on the throttle?  See if yours can be backed off a bit and that may lower your RPMs as well.  I think of it as a secondary idle adjustment since it can work that way.  It takes all the adjustments off the cam and those other stops. 

I had a pump come to me and that was how the PO set the idle.  I had my head full of possibilities trying to do it properly and got good light on that lever/ rod stop connection and figured it out.  Once I got the RPMs down I went back and adjusted the fuel delivery screw down a bit and it had no power off idle.  1/4 turn back in raised the idle too much so I had to adjust the green screw a tad.

Hope that gets it. 

[joe peat]

Cheers for the responses. The only thing I have done to the pump is change the main seal whilst on the van. It was on reassembly that this fault manifested. I did have to disturb the fast idle spring in order to remove the top cover. Having tried all the adjustments helpfully suggested I think I should  re-investigate said spring and associated parts. Would anyone per chance have an exploded diagram or photo of the fast idle spring assembly? It's quite hard to see exactly how the pins and slots interface on the parts diagrams etc I have found so far. Thanks so much again for all the help.

[libbydiesel]

I don't understand what you mean by 'main seal'.  To me that means the man shaft seal that is behind the sprocket.  There is no need to remove the top cover to replace that seal. 

If removing and replacing the cover caused the issue, then I would assume you either did not get the small idle spring hooked up correctly or you put the accelerator lever to shaft orientation incorrectly.