Author Topic: switching to Merc nozzles (Read 2433 times)

geetus · « **on:** May 12, 2008, 09:53:00 pm »

Hey guys I picked up some mercedes nozzles for my aaz and I am wondering if there is anything special to do when swapping them into the old injector bodies. I have heard of getting new heatsheilds?, Also do they have to be re calibrated?
Cheers, Ryan.

OM617 · « **Reply #1 on:** May 13, 2008, 02:15:47 am »

Yes, new heat shields. Any time the nozzles are changed the injectors must be recalibrated.

jtanguay · « **Reply #2 on:** May 13, 2008, 04:27:01 am »

don't forget to lap the mating surface on the injector otherwise you might get a leak. vince waldon has a site with some good info on how to do it.

geetus · « **Reply #3 on:** May 13, 2008, 08:35:44 am »

What is involved with the recalibration process.?

zukgod1 · « **Reply #4 on:** May 13, 2008, 08:52:51 am »

There are shims on top of the spring inside the injector and each shim is a specific thickness.
Add shims and the pop off pressure raises, remove and it lowers.
You need to have them calibrated so each injector opens at the same time for each injection cycle other wise you can have one that opes at say 2deg BTC and one that opens at 5deg AFTC giving you poor mileage lots of smoke and messed up EGT's.

geetus · « **Reply #5 on:** May 13, 2008, 12:41:44 pm »

All right! I feel much more enlightened.
Very good explanation. Thanks.
And I checked the site for lapping the nozzles. Some good info there too. I will be getting everything sorted for the nozzles in the next week and hopefully see some good results.
Cheers, Ryan.

Author Topic: switching to Merc nozzles (Read 2433 times)

OM617