78 VW Rabbit Diesel TIming Belt/Injector Timing Question

does it run better when you pull that cable out?

I installed a head gasket with four notches just like the original. The car smokes quite a bit when I step on it, but there is no power. I am confident the cam, crankshaft and injector pump are lined up...so it must be the injector pump needing some fine tuning. Can I do it myself, or do I need a Bosch certified tech? Anyone know how much I should expect to pay to have the injector timing dialed in?

Also, It does not seem to make a difference in performance whether the choke is in or out.

Thank you!

Jeff

dave AKA vwdoc1 wrote:

Jeff:

The cable isn't a choke, although it serves a similar function. When you pull it out, you are actually advancing the injection timing around

5 degrees to give the fuel more time to burn in a cold engine. You can buy the injection timing tools for about $100. I got mine at Parts Place in Auburn Hills, MI. The Bentley manual tells you how to do it. It is not that difficult. Did you replace the heat shields under each injector? If you don't, you will burn out the head in 5000 miles.

I don't know what the dealer charges to time the injection pump but I would guess two hours worth of a mechanics time which is $70/hr by me plus misc. shop supplies, maybe $150-$170 or so. That includes time to test drive the car too.

I put 300,000 miles on my 81 Rabbit Diesel LS. It was a great little car. Enjoy! TEMiller

JH wrote:

Hello All, I just replaced the head gasket on my '81 deisel and have the same problem with injection timing. I have the flywheel and cam aligned at TDC of piston #1. But how do I know when the injection pump is fueling piston #1? I can put a dial indicator in the hole and it rises and falls 4 times every 360 degrees, no? So how to align it for TDC #1 ??

The Bentley manual says how to adjust and check the rise amount on the pump cam, but not really how to time it correctly before timing belt installation.

Any suggestions?

thanks, Caleb

There's a round pin that you insert through the hole in the sprocket and into a hole on the pump. That's #1.

JoBo

JoBo, I saw the pin, but there are 2 holes spaced 180 deg's apart in the sprocket! Which hole is for #1?

caleb

Jo Bo wrote:

There is a notch in the injection pump sprocket that lines up with a line on the top of the injection pump. When these two marks line up, plug in the bolt that holds the injection sprocket in place. I'm finding that is a "rough" timing mark after replacing the timing belt and tensioner. You then use the dial indicator to measure and adjust the injector timing.

I do have a question. The Bentley manual says to adjust the dial to .83 mm. Since the injector pump is worn, could I increase this measurement to compensate for wear, and advance the timing a bit?

Thanks,

Jeff

mrbisset wrote:

No! A worn pump will only generate less pressure, the timing is affected by the adjustment you make with the dial indicator. Setting this value compensates for any wear in the mechanism. A worn shaft bushing on the pump will cause it to suck air past this bushing instead of fuel from the tank causing a great loss of power. Make sure all your fuel line connections from the filter to the pump are snug and not allowing air to get in. That too will cause a loss of power. TEMiller

I have a question regarding setting the fuel injection pump timing:

I have followed the steps in the Bentley manual. Using the dial, I have found that the injection timing is set to 1.32mm. I have loosened the three allen head bolts on the injector pump plate. I cannot not remove the bolt w/ the yellow paint and the standard type screw head, it's stuck.

Do I need to loosen the screw with the yellow paint? Have I loosened the correct screws? Now, how do I adjust the pump down to .83mm?

Thank you!

Jeff

n> Also , the instrument is sensitive , sometimes when you tighten the fuel