Help 1981 1.6 nt wont idle down after reaching higher rpm

iamspencer · Post by **iamspencer** » Wed Sep 23, 2009 10:00 am

hey,

while driving or at idle when the rpms get up to guessing 2500 it wont idle back down, and its not the linkage getting stuck the linkage will be at idle but the motor will continue to rev until you put it in gear then it drops down to idle, all you have to to is let the clutch out into gear everso slightly and that will do it. it used to only happen sometimes but now its all the time. i can sort of avoid the problem by keeping it in a higher gear and keeping the rpms down but i cant figure it out

any ideas?

thankyou for any help

-spencer

bscutt · Post by **bscutt** » Wed Sep 23, 2009 11:46 am

it could be runaway (sucking up engine oil into the intake and burning it) but that usually won't back down without stalling out the engine in gear so I doubt it. Sounds like an Injection Pump issue and I'll have to defer that to some of the forum IP experts

You try lubricating the throttle shaft and springs on top of the pump, they can bind up over time

82vdub · Post by **82vdub** » Wed Sep 23, 2009 1:18 pm

Are you sure that the throttle linkage (and cable) are all working properly and that the arm on the IP isn't sticking compared to the throttle arm on the IP? Just a couple things to check.

Quantum-man · Post by **Quantum-man** » Wed Sep 23, 2009 5:50 pm

Have you recently screwed the max fuel limiter [collared screw] in to get more power? If so try backing that out slightly.

Post by **Fatmobile** » Wed Sep 23, 2009 10:16 pm

Yep, left over fuel after the burn.
Overfueling or a funky injector.

Kanzan · Post by **Kanzan** » Thu Sep 24, 2009 7:34 pm

iamspencer, take a look at this thread, I think it is along the same line. My 81 Caddy 1.6na has been doing the same thing for about 500 miles, I haven't found the answer yet. Kanzan

viewtopic.php?t=9549&highlight=

Kanzan · Post by **Kanzan** » Thu Sep 24, 2009 7:40 pm

Take a look at this one also. Kanzan

http://www.vwcaddyforum.com/showthread.php?t=37264

rabbit_man · Post by **rabbit_man** » Thu Sep 24, 2009 10:13 pm

Mine did that too, the throttle lever was sticking ever so slightly that it would maintain a high idle.

Try filling the little "dish" in the lever with some kind of lube.

iamspencer · Post by **iamspencer** » Sun Sep 27, 2009 6:49 pm

hey everybody thanks for all the feedback, i was thinking that it was an ip problem and not, blow by

for a few reasons
i know that before i bought it it had bad dirty home heating oil in it and that caused the car to stall out and not start (actully happend on my first test drive of the car) so he guy had the fuel system flushed a few times with new filters and then it ran ok so i bought it

it only has 65,000 miles on it and that seemed really low to be having blow by issues

and it doesnt burn much oil, it burns oil but not as much as i would expect it to if this was being caused by oil burning

the problem used to happen but if i wiggled the pedal around it would idle back down now the only way to get it to idle down is put it into gear.

so for example if i drive up a hill at the high range of third gear and come to a stop at the crest while im in neutral at teh stop light it will be idleing really high if i let the clutch out even like half way into gear for a second and back in to neutral it wll idle down fine

and third

iamspencer · Post by **iamspencer** » Sun Sep 27, 2009 6:53 pm

i cant remeber any surging at all it never "runs away" or changes rmp un explainably

it just wont go back down to idle if its reved up or durring driving

thanks for everything

-spencer

iamspencer · Post by **iamspencer** » Sun Sep 27, 2009 6:58 pm

now thant i think about i did some times get a jerking/ surging symptom around 40 mph a slight change in rpm on my part would make it go away, it was never a big problem i never say a conection betwen these issues

iamspencer · Post by **iamspencer** » Thu Oct 08, 2009 6:23 pm

anybody?

iamspencer · Post by **iamspencer** » Thu Oct 08, 2009 6:24 pm

anybody?

is it injection pump releated or cylinder related?

Kanzan · Post by **Kanzan** » Thu Oct 08, 2009 7:14 pm

ianspencer, I am certainly no diesel expert, I am having the same problem with my 81Caddy 1.6na. I think part of the broblem, is that there are so many causes of this problem. Defective delivery valve, defective injector, loose IP bolt, idle set to high, pump to rich, pump to lean, dirt in pump, stuck governor, etc, etc. Hagar said to lower my idle speed, that did seem to help, but I still have uneven acceleration and deaccleration, and some jerking. Getting ready to run a can of Diesel Purge through my engine, along with a new fuel filter. If I find anything that helps, I will let you know. Kanzan

Quantum-man · Post by **Quantum-man** » Fri Oct 09, 2009 3:53 am

Quantum-man wrote:Have you recently screwed the max fuel limiter [collared screw] in to get more power? If so try backing that out slightly.

"Any body ....anybody"
A reply would be nice B4 proffering more ideas

EDIT ...OK another thought:
Sod all to do with cylinders IMO.

My compression is low, blowby 'high'; fuel economy into the 40's mpg Yankee baby sized gallons.
Accn reasonable, max speed somewhere in xs of 105 mph.... Idles smoothly, starts easily, never connected up cold start....