Cold start w/ PP764 Nozzles

Little backstory: I bought a 98 beetle (5speed) about 4 years ago. When I had it the previous owner used to run it on veggie fuel. I ended up taking all the components out and returning the car back to stock.

Fast forward not even a year afterwards timing belt snapped and ending up putting a brand new head on the car. Installed a new fuel pump seal kit, egr, starter, battery, glow plugs, fuel filter, air filter. Car ran normal.

The past month ago I installed used injector with pp764 nozzles. They were pressure tested and calibrated by DBW LLC and have little less then 30k on them. The car has new life in it and pulls great!

The thing I noticed though is that when its cold it takes a few more cranks then normal. I ended up dropping the IQ from 5.6 / 5.8 to 4.0 and bangs around a little harder then before when its colder. By the way my car is completely stock all I did were install injectors/nozzles.

So my question is:

When Im driving the car as soon as I turn it on I always make sure I drive slow until its warmed up. When I'm leaving in 1st gear the car seems to bog down and then all off a sudden it kicks up and jolts me to the back of my seat. Even though I'm not pressing on the pedal and harder (once again I drive really slow when engine is cold) It does this until the engine is warmed up and then its fine.

Anybody know what could be causing this? Seems like the turbo just kicks in or extra fuel gets dumped but I'm not even pressing the gas hard enough to do that. I also dont think its the clutch slipping because it pulls fine in 3rd and 4th.

Thanks

Even though you have not gotten a code for it, that is classic IP going bad behavior; the thing is you may not get a code until your pump is almost dead. I would suggest you start running a lubricating additive asap to help keep the timing circuit alive as long as is possible. I apologize for the bad news, but I only know what you are talking about from personal experience. My rebuilt pump should arrive at my home today from DFIS, Portland. No they are not cheap, but their work is top shelf quality. You may get by with buying a used pump from a TDIClub member and be okay for a couple of years. Just out of curiosity, when was the last time you checked and drained your fuel filter? Water in your fuel will also kill your injection pump.

Last time I changed the fuel filter was about 20k-ish miles ago. I actually have a new one on the way.
The thing that makes me think its not that is because it just started with these new nozzles. But ill replace the filter asap and go from there.

Personal experience advise is not to be ignored, we can only hope he's wrong about your car. But I would rule out everything else involved.
Some dumb stuff: Put the battery on an overnight charger, see if that helps the cold start. Check the actuator functions correctly, could be the vanes are stuck wide open. Real stab in the dark-try driving with the MAF disconnected.

Are you seeing smoke when first starting? I'm thinking that this is a lot of nozzle for stock (no tune; stock turbo etc.).

Check timing. Advance it if you can.

Rrusse11 said:

Here's a thought, timing is probably off, (too advanced?) and rather than lowering the IQ, increase it! Too much fuel too soon, in a cold chamber.
My $.02.

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This ^^
Take your iq up to around 7, or so, and see if that doesn't clear it up

Sent from my mobile look-at device

\/\/0J0 said:

This ^^
Take your iq up to around 7, or so, and see if that doesn't clear it up

Sent from my mobile look-at device

Click to expand...

Thanks for the recommendation. Today is the first day with it up in the 7's. Seems to have cured the bucking it was doing early in the morning (but its only the first day). Going to try it out rest of the week at 7 and possibly work my way down to lower the IQ as it feels a lot slower.

Thank you again

Update: Well after driving it around IQ 7 the bucking stopped but starting the car became harder. Ended up advancing the timing a little bit and it runs smoother and starts great now.
Thanks everyone for the help. Now I have to just play around with the IQ.

You should look into getting a tune if you want to be able to fill a glass with a firehose.

I'm not sure there are any folks around here left to disagree with me, but veggie oil kills injection pumps in these cars. I know one club member who used to replace his IP annually when running veggie oil. Odds are residue has caramelized inside the pump and it's not delivering fuel in any quantity, or consistently. Time for another pump. You could get yours rebuilt, but in some cases that can cost as much as a replacement.

You could have other issues, such as residue accumulating on the valves or compromising piston ring sealing (how's your oil consumption?), but I think pump replacement is the first step.

IndigoBlueWagon said:

I'm not sure there are any folks around here left to disagree with me, but veggie oil kills injection pumps in these cars. I know one club member who used to replace his IP annually when running veggie oil. Odds are residue has caramelized inside the pump and it's not delivering fuel in any quantity, or consistently. Time for another pump. You could get yours rebuilt, but in some cases that can cost as much as a replacement.

You could have other issues, such as residue accumulating on the valves or compromising piston ring sealing (how's your oil consumption?), but I think pump replacement is the first step.

Click to expand...

I replaced the gaskets on the pump the first year I owned the car, when I opened it up I didnt see any "caramelizing." It did though have a little bit of a yellow tint to the metal. Im pretty sure its not the valves because the timing belt also snapped on me few months after buying the car.....so it had a brand new head. ( Ive owned the car for about 4 years now ). Doesnt burn any oil and when Ive cleaned the intercooler piping I just get a little dribble of oil.

I did do some research and I heard when upgrading nozzles its recommended to advance the timing. *Knock on wood* Its only been two days but so far so good.

If you get a scenario like the engines starts and idles but it seems to "hunt" a bit (RPM cycle up and down 200 RPM or so), or if you open the throttle and the engine doesn't want to accelerate above 1800 RPM and then all-of -the-sudden the RPM takes off the timing circuit in the pump is hanging up, or the vanes inside the front of the IP the "lift pump"--sort of-- doesn't lift enough fuel and then there will not be enough fuel pressure internally to give proper advance, etc., etc.. Have you removed the 10mm head case pressure relief valve yet? If you have was the roll pin flush with the bottom of the valve itself? This is another possible place to look when the engine acts a certain way and does not run correctly or consistently all of the time. I have personally spend hundreds of hours in the past "looking for love in all the wrong places"; in that I mean I wasn't looking for the solutions I did not want the problem to be. If you need a pump Frans has good used tested and sealed pumps for less than $400.00 delivered to your door.

Maybe not the best place to bring up this question, but this thread almost begs it...

Given that bio-diesel is known to clean the crap out of the fuel system I'm wondering whether there could be any value in running it in order to try un-doing veggie oil damage? NOTE: I am not in any way a proponent of bio-fuels (and certainly not veggie oil). Of course, there's the the issue of probably needing one or two fuel filter changes.

So I hooked up vcds and went to group 013. I have my iq set at 5.4 and timing is a little more advanced at 55.
So it reads:
Cylinder 1 (1.15 mg/str)
Cylinder 2 (-0.33mg/str)
Cylinder 3 (-0.45mg/str)
Cylinder 4 (-0.35mg/str)
Is this something serious? I read it's fine as long as the deviation isn't over 2.
Also I am waiting on the o-rings for the injection pump case relief valve like someone else metioned.

I also will probably bring my iq back to around 6ish

Double-check your fuel lines pre-IP to make sure that things are tight and that you're not getting any air in the lines. If you are running a stock filter setup with a Termo-T be sure that that Tee isn't cracked.

I recently experienced hard-starting due to air incursion, something that I hadn't been exposed to before, and as soon as I got things tightened up starts were once again quick. A little air goes a long way toward creating pig-ish starts.

UhOh mentioned using Bio-D, not because he is a proponent but I believe because it makes sense. We know that even a 2% blend of Bio-D add 60% more lubricity, so more is likely even more so. It would not hurt I believe, to run a few gallons of Bio-D through the system to help remove any hidden deposits in the pump or the general fuel system. Bio-D is a great cleaner, so keep at least one extra fuel filter handy.
After I re-read this post I saw there were larger sized nozzles installed, that change would give the plungers a range of stroke; maybe it is something, maybe it is not.