Bosch injectors
I have recently purchased a 1992 535i with 132,000 miles, I adjusted the valves, due to hearing valve ticking noise. It still makes the noise and the ticking increases as I accelerate. I am now thinking of replacing the injectors. which would you recommend: Bosch 280 150 556 Design II or Bosch 280 155 710 Design III?
Super Moderator
The noise frequently isn't the injectors, its the orings. The injector seals and
oring act as noise and heat insulators to keep sound from transferring to the head or manifold where its amplified... I would replace the orings and seals and replace the eccentrics on the valves and then readjust them.. long before i would buy new injectors..
Originally Posted by The Don Man
Major Contributor
go with mustang 19lb injectors.
5-10 Grand Master
hey bill what do you think the possibility is the inductive pick up died and the computer has gone to gang fire from semi? that makes quite a racket, m52 and m52tu's seem to eat cam sensors and you can tell without reading codes due to the hammering injectors on a normally quiet motor. that or he's not use to a early bimmer's injector rap, i get that question a lot from new bmw owners
all america wants is cold beer warm cat and a place to take a poop with a door on it
3 Grand Master
Dude, both of the parts mentioned ARE 19# injectors.
Anyway.
The M30 has banked injection. Most good diagnostic tools can fire the injectors, and you'll be able to get an idea of how much noise they're making. Some noise is inevitable, and there's not much to do about it. Sure, replace the O rings if you want. Replace the eccentrics if the adjustments were difficult to get exactly on spec. But there's no cure for the inherent-in-design ticking, which is why there's a large piece of hood insulation.
best, whit
3 Grand Master
Winfred, can a Motronic 1.3 M30, a single sensor box, actually run without that CPS?
I feel like an idiot saying this, but the M52/tu are supposed to use gang fire under certain conditions (warmup, some other driving scenarios). Those cam sensors do suck.
best, whit
Super Moderator
Lowell , Winfred is talking about the sensor on the plug wire that
controls the sequencing of the injection not the crank position sensor...If the inductive sensor on the plug wire fails then it goes into gang firing as Winfred said, since the m30 is a semi sequential design meaning that it triggers the injectors in 2 banks of 3 every other revolution, when it goes into the gang fire as he calls it, then it triggers all six at the same time every revolution but decreases the volume of fuel by 50% .. And i would imagine that all six triggering at the same time would make a much louder noise... Winfred might be right that this is whats happening but in addition to checking that i would also check the eccentrics and the seals too to be certain.
Winfred, can a Motronic 1.3 M30, a single sensor box, actually run without that CPS?
I feel like an idiot saying this, but the M52/tu are supposed to use gang fire under certain conditions (warmup, some other driving scenarios). Those cam sensors do suck.
best, whit
3 Grand Master
I knew that the sensor wasn't necessary for functional operation; didn't know that the DME adapts injection to it, but it makes a lot of sense.
best, whit
Are the orings and seals on the fuel injectors?? the Eccentrics is there a way to tell if they are bad??
3 Grand Master
Yes, here's a picture of the O ring(s):
(above the cracked pintle caps in the pic).
Worn eccentrics are hard to adjust to spec (because they've been worn at the point where specification would be met). You can visually look at them for wear, for what it's worth, by removing the eccentric. But, I trust my feeler gauge more than my eyes.
best, whit
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