Quote:
Originally Posted by Scharbag
I am chasing a bit of an annoying pre-detonation issue while using a tune. I am running Dinan now (car came with a Dinan tune). I have the Dinan bored throttle bodies (previous owner installed these). When I run my Alpine tune (91 or 93 octane stage I files) with 91 octane fuel, I run into bad low RPM pre-det and some higher RPM pre-det. This happens even when it is chilly out. If I run 94 octane fuel, the pre-det is significantly reduced while running the Alpine tune.
The Dinan tune (re-installed it a few weeks ago) has been pretty free from pre-det. One time it did briefly while accelerating hard at low RPM. High RPM has been fine. I have been running 94 octane and the next fuel-up I will try it on 91 octane.
I am not sure if the Dinan throttle-bodies need to be considered while tuning and I also do not know for sure if the Dinan code takes them into account.
I do not suffer from pre-det when using the stock 241E programming. I have never had a code thrown by the ECU regarding knock or fueling issues.
Richbot: did you replace your injectors or have them serviced?
Given I can walk to work and I have a spare car, I am considering pulling the injectors and having them tested just to remove that variable from the equation. Newinfo.tis implies that it is easy to take the rails out as a complete unit. Is this the case?
Any other avenues that I should explore?
Cheers,
Cheers, |
Scharbag - I did this late last year and forgot to do my writeup. I would recommend sending your injectors out for cleaning and repair (i.e., new seals). They will flow test them so that you can hopefully rule out injectors when you get them back. Much cheaper and good first option before buying new injectors.
I used this guy:
http://www.mrinjector.us/
Very quick turnaround and delivered as promised. All injectors were cleaned and flow-tested. My injectors weren't all that bad (for a car with over 110K+ miles at the time). I'll see if I can dig up the stats to share.
As for removal, never found an E9X specific DIY procedure, but there's one on Pelican Parts for a generic E90 that is close enough.
Short form on the procedure:
1) Remove airbox and plenum (same as what you would do if you were going to change spark plugs, etc)
2) To minimize fuel flow from the injectors, I pulled the fuel pump fuse (sorry, forgot which number) and opened up the gas cap. Parked the car overnight as well.
3) Injector clips are fairly easy to pull off. Just pry the paperclip like retainer (be careful not to lose it of course).
4) Loosen a couple screws and then, just pull straight up on the fuel rail to remove the injectors and rail assembly
5) Each injector is then pulled off by hand off the rail. Some injectors might be tight, but if you give it a gentle twist and pull (make sure it's 90 to the rail), they will all pop off easily
6) Assembly is just in reverse. I lightly lubricated each seal with a small drop of 10W60 and they popped back in with no problem