Rough Idle and Quantity adjuster problem

Let me first say this is one of the Greatest sites I have seen on the web!!

A little history. I bought this 1999 beetle about a year ago. The guy said he just put a new timming belt on it. The car ran great. I put about 25,000 on it when I started getting a error code from the Quantitty adjuster Upper limit reached (inermitant). It was running fine so I let it go. I started haveing a very rough idle it would pulseate very fast up and down. I have cheaked the ohms across #1 & 3 terminals and found them to be 13 ohms. Whitch seems to be out of spec for the QA.

I tried a hammer mod but it didn't help. If I adjusted the idle lower it helped the idle issue, but would stall when I came to a stop. If I adjusted the idle up, it caused the idle to get even worse.

I timed the car a couple of months ago and the found the idle off again last week? The belt looks good.

The car runs great down the highway it's just at idle that I have a problem and is not just a little rough its allot.

If the Quantity adjuster is bad can I replace just the Qa?
Where is the best place to get a Quantity adjuster or if I have to? Where is the best place to get a New injector pump with out spending a fortune?

Thanks, eric

What is the injection quantity reported by VAG COM?

QA housings are hard to find... look around for people with dead IPs they want to get rid of (check the junkyards and dealerships)

Runonbear

I will try to get the Quantity adjuster info tomorrow. Any chance you know a good diesel doc in the Los Angles area.

Thanks, eric

Harveaux is near LA...
Wild Rose Motors Ltd
148 Lloyd Ave # F
Fullerton, CA 92833
(714) 449-0485

check grounds and connections on the ECU

check grounds?

I have found the ECU and the conections look good.Should I spray some contact cleaner on then just to asure good contact?

what ground conections should I look at?
thanks, eric

do you have a vag-com? if yes set QA to, some of the guys like 2.8 some like 4, I have mine at 3.6. You need to start here. now a bunch of sensors talk to the ECU and the QA gets adjusted accordingly. If the ground under the battery and the grnds around the ECU are good, not just look good you have to take them apart and clean them, then follow the procedure from your Bentley on checking the associated sensors. The QA should read 1 ohm to grnd, across the speed sensor 1.15K ohms, needle lift sensor 90 ohms, fuel temp 2.3k ohms, modulating piston 4.9 to7.5, these are the numbers on my 03 beetle. Once you determine they are all good look to the ECU. Take it apart and check for a bad solder joint Check the post "ECU RESSURECTED" do an advanced search

Vag Com report

THANKS ALlOT!!!! REALLY THIS SITE IS GREAT!!!

I hooked it up to the vag com today. The injection quantity is not steady it bounces up and down. from 0 to 3.8 the injection timing bounces from 0 to 1.5. I also notticed that the duty cycle bounces from 2.8 to 44.

I am new to this, so I thought I would save a buck and buy a vag com on ebay, 20 bucks, how can you go wrong? Well the cheap ones don't let you into "basic settings" and won't let you save an "adaptation" so I guess I will get a better one this week.

I did clean the ground connections. No change.

It almost seems as though the TB is bad or the tensioner. I have looked at the belt and it looks good, there doesn't seem to be any play or movement in the belt while the engine is idleing.

I know I have some oil in the intercooler and the egr looks pretty dirty. but not stuck. niether is the anti shudder valve stuck. I plan to clean the intake and bypass the egr but I would like to fix this idle problem first or do you think that a dirty intake and egr valve could cause this type of problem?

Thanks again, eric

QA is jumping around because something is telling it to, when all is correct it will hold steady. In regards to the EGR pop a note to alphasenior or runonbeer they are mechanical experts on these engines

QA won't have anything to do with the timing. I would try to do the hammer mod again (you shouldn't have attempted this without a VAG-COM).

Bump it so the minimum is 2.0. that will at least give you a little bit of smoothness.

Pretty much you should look for diesel injection service in portland. They will be able to rebuild your injection pump, but the QA housing may still need to be replaced. They might have another one to put on.

Have you taken a look under the top of the injection pump. this will not affect the mechanical QA adjustment. see if there is any rust on the QA housing mechanicals.

You might also have a problem with the #3 injector lift needle not working properly...

You can always buy the complete version from Ross-Tech.com for like $100 or buy a cable for $300.

I have been resealing these pumps for about a year now. and once in awhile I get one that afterwards, the QA jumps all over the place, and makes the car shake very much bad. I have determined that you can adjust ( a little bit) the quantity, by shifting the whole upper housing forward or backwards to adjust the idle speed/quantity. the housing is designed to move left and right, but forward and back, seem to adjsut it the small amount they mostly need.

and if you are nervous to attempt it, you can always scribe the housing all over, to be able to put it back how it was.

New vag com & hammer mod

OK, so I got a new vag com program from ross tech. I redid the hammer mod til the injection quantity was around 2. The idle started humping really bad. I noticed that when the injection quantity was around 6 it idled better, and if I played with the gas peddle and released my foot slowly I could get it to idle smoothly, tap the peddle and it's back to humping again.

Alphaseinor said the quantity adjuster has nothing to do with timing but I thought I would check it again. It was off again. I set the timing and still humping idle. I should mention I don't think I can adjust the timing anymore. I have rotated the pump shaft clockwise almost as far as it will go to get the timing right. Is this normal?

I picked up a set of used injectors off ebay. I am hoping to use them to figure out this problem? Mainly I wanted the #3 injector to see if it made a difference in the idle. Since I am new at this I would hate to buy a new #3 injector or a new pump and have guessed wrong.

Thanks, eric

Qantity adjuster Is clean

I Forgot to mention I looked in the Quantity adjuster befor I redid the hammer mod. I looked ontop and under the quantity adjuster in the pump inself and it looks band new, very clean.

Thanks, eric