Low speed surging - updated

[stewardc]

Oooookay, buddy. Don't get all excited over this.
I'm done.

[macka]

so are you guys smoking a cigarette now? 

[stewardc]

so are you guys smoking a cigarette now? 

Indeed we are. Handled by private post.

[burn_your_money]

Shucks we missed some hot action it sounds like.

Thanks for keeping the board clean guys

[Baron VonZeppelin]

yeh well .... that don't smell like store bought tobacco

you hippies finish off that peace pipe and get back to work already 

lol

[2strokesmoke]

Hi, was this surging issue ever figured out and /or corrected ??
I 'm having the same issue myself.
Thanks,Mike

[stewardc]

Is it consistent at a certain RPM? (mine is about 1500-1700 and every time in any gear.)
Have you done anything to the pump or is it stock?

[the caveman]

I was curious about this topic since before i got a wonderful Performance Diesel [Giles] pump. After i installed it, i had a bit of hunting, surging, but only slightly, worse at idle running on VO [ which begs the brand of fuel question someone mentioned]. I turned in the fuel screw 1/8 turn and it went away. Personally i would also question fuel quality.

[stewardc]

I've tried all fuels and run additive in every tank. What was an inconvenience has grown into a full fledged annoyance. Additive solved the problem at first, but it steadily got worse. Nothing matters now.

[theman53]

Maybe too much additive? why only that rpm range I wouldn't know, but a guess.

[2strokesmoke]

After 1 day of driving,sence I un-Modified the Gov intermediate spring(removed shim washers-back to stock) and turning the fuel screw in a bit-the "Bucking" or "Surging" has greatly diminished. It  bucks ,while driving a cold engine. With engine up to temp (192 F) It's quite mild. I'll see what this condition is like the rest of the week. If it remains the same,I'll try turning the fuel screw in a Lil bit more.
Remember,I'm running a stock IP,with only Gov Mod and Advance Mod.
I must Honestly report: After removing intermediate spring shims and turning in the fuel screw to compensate-the low and Mid RPM Power has increased dramatically !
(as in my Thread "82 Caddy 1.6NA Low Mid RPM Bucking"
I had followed the WRONG thread while performing the Gov Mod.  Oooopsy ! LOL  Learn the hard way sometimes.
I'll update at the end of the week, on how she's running.
After several hours of reading through many prior threads' I found than many others have experienced this Bucking or surging.  Many people have reported many different causes,of the same basic symptom.
A few were:
Camshaft timing off time just a little bit
IP Static timing retarded
IP rear mount bolt loose
The addition of  3oz Stanadyne per tankfull,was reported  to help and if I read correctly,recommended by Giles (in  one of the threads I read)
Anyone elses feedback,is welcome.
Thanks ,Mike

[stewardc]

Thanks for the feedback. I'm glad you could make it some better. I've tried everything, myself, to no avail.
Anyone else experiencing this be sure to chime in.

[BellCityDubber]

I'm bringing this one back from the dead

I'm having a similar problem.
under part throttle while at cruising speed (any gear) between 1500-2000 rpm
I'll get a jerking which becomes more and more violent

I checked the lines, there doesn't seem to be any air bubbles
(I bought a new filter, just to be sure)
although I did notice that the little metal strip that goes from the injection pump area to the dipstick has broken. 

Would anyone think that this would be poor pump timing?

[Quantum TD]

A friend had similar surging on his 1.6NA unmodified pump. He tried to increase the internal pressure, and it didn't help. H finally reasoned that it must be the governor. Turns out the lock-nut on the governor shaft was loose, and the shaft was moving ever so slightly to cause the surging.

[BellCityDubber]

I would think it's a later style pump, it's a 1.6td from a 91 mk2.
I also forgot to mention, it's a giles pump.
I got poking around and I noticed there was no washer, or lock washer on the rear pump bolt. it looked like the bolt head was digging into the rear support for the pump.  the washer and lock washer seemed to help a bit (or maybe I shifted the pump while tightening it down, and it was doing it less.

also... while taking a look, the pump to block bracket... it looks like it's missing a bolt, but I cant quite see around the pump
does anyone have a good picture of the pump to block bracket for a mk2? and how many bolts hold it on?