10MM Injector pump in Auto Trans?

Can you install a 10mm pump in a car with an Automatic Transmission temporarily while you send the 11 out for repair? Just wondering if this has been done before. I have a new 10mm coming for my '01 manual and was debating about sending it out for repair as a common spare for both cars.

Yes it would work. Due to the power requirement of the transaxle, it would seem a little less interesting than the stick. This assumes you have the original nozzles, which are smaller than the ones in the 5-sp.

In the same way most people like to install bigger nozzles for more power, smaller nozzles will result in lower power.

But your original idea of using a single spare pump as a spare you have on hand so that you won't experience down time is good. Do it.

Powder Hound said:

But your original idea of using a single spare pump as a spare you have on hand so that you won't experience down time is good. Do it.

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Agreed with PH but in the interest of commonality why not upgrade the automatic's nozzles while you're waiting on parts?

Switch over the injectors from the manual car, send the automatic injectors out for flow matching & new nozzles, swap those in when they arrive and send out the manual injectors for the same treatment. Then you'll have a matched set of IPs & balanced nozzles & injectors to work with.

Thanks for the feedback guys. It was actually the manual that was messing up, I was trying to justify buying one of the new 10mm pumps from IDParts. I did, and it solved all of my injection timing issues on the manual. Now I just need to send the old one out and have it rebuilt as a spare. Thanks for the injector ideas, doesn't seem to make sense to use a larger pump with smaller injectors, not sure what VW was after on that one. Thanks again!

I have to assume the 11 mm cost more which is hard to believe since there is probably 2 cents more material and equal manufacturing cost. Most cost added were likely from redsign and low production numbers vs the 10 mm. they should have scraped the 10 mm and put 11mm on both versions

I may be wrong but 10mm vs 11mm is the stroke lenght of the injector? more stroke = more pressure = shorter life or bulkier design ($)

from the FAQ

One of the improvements made on the A4 engines compared to previous models involved the increased fuel injection pressure from the injection pump with optimization of the fuel injectors. Manual transmission A4 TDI's have 800 bar (11,760 PSI) pump side pressure with 1100 bar (16,170 PSI) injection nozzle pressure. Automatic transmission A4 engines have 950 bar (13,965 PSI) pump side pressure with 1350 bar (19,845 PSI) injection nozzle pressure. To achieve this increase in pump and injection nozzle output pressures in the automatic transmission engines, the single injection pump plunger on the BOSCH pump was changed from 10mm to 11mm. This was required for emission purposes allowing the automatic version to inject the required quantity in the very limited time available at higher pressure, with a resulting 20% reduction in particulate emissions.

Powder Hound said:

Yes it would work. Due to the power requirement of the transaxle, it would seem a little less interesting than the stick. This assumes you have the original nozzles, which are smaller than the ones in the 5-sp.

In the same way most people like to install bigger nozzles for more power, smaller nozzles will result in lower power.

But your original idea of using a single spare pump as a spare you have on hand so that you won't experience down time is good. Do it.

Click to expand...

I have a similar issue with my car. I found a really cheap 10mm pump but have an automatic. If I were to put this in would it help or hurt my MPG? Power is not an issue to me!

Nich said:

I have to assume the 11 mm cost more which is hard to believe since there is probably 2 cents more material and equal manufacturing cost. Most cost added were likely from redsign and low production numbers vs the 10 mm. they should have scraped the 10 mm and put 11mm on both versions.

Click to expand...

Yeah check out some of the vendor sites or a dealer and see how large the price difference is....you might die

codylent said:

I have a similar issue with my car. I found a really cheap 10mm pump but have an automatic. If I were to put this in would it help or hurt my MPG? Power is not an issue to me!

Click to expand...

Did you installed the 10mm pump into our automatic 1.9TDi. I did and it smoke like hell and the engine surge like crazy

My 2000 NB started life as an 4 speed automatic (the infamous O1M). At 252,000 miles, that finally gave up the ghost and I had a 5 speed manual put in. Having the 11mm pump with the smaller injector nozzles pretty much made it the equal of the 10mm pump with the stock nozzles for the 5speed.



Now at 297,000 miles, my fuel pump died, and I also had much larger nozzles put in - nice bump in power, but it also smoked quite a bit. (The fuel pump was replaced with another 11mm pump).


The following summer, I took the Beetle to Jeff at Rocketchip, and the first comment he had after I told him what was already there was "Smoke much ?" "Like a train any time I hit the throttle". He slightly customized a Stage 2 tune to reduce smoke on the daily driver range (2000-3000 RPM) , but let it all hang out on the upper end. The result is a pleasant to drive daily driver (that doesn't smoke too bad) that can legitimately pull 5000 RPM + on the top .


Tongandiesel - I think you had some timing issues on why your car smoked so much.