Injectors, injectors, injectors....

[Three Dee]

No doubt about it. at least one of the injectors on my M20 is dead. I've been expecting this for awhile, and recently the car developed a heavy miss and I ended up having the car towed home. I can start it, and it will idle, sometimes almost smoothly, sometimes barely at all. I have good spark about 40lbs fuel pressure, and good fuel flow as far as the injector rail. I have no real idea how many miles are on the injectors, since they were with the engine when I dropped it into my car.

For the record, it's an '89 325i engine in an '86 325.

So, I'm looking at the various possibilities for replacing the injectors, and I like the idea of upgrading to the later style GenIII injectors which are (I believe?) found on M50-equipped cars. The four-hole design makes sense to me, especially if they really do stay clean better than the one-hole design. However, I'm finding 17, 19 and 24lb injectors on good ol' E-bay which promise better power, fuel economy and increased hair growth on my chest, so I'm a tad confused.

The engine is stock, and so is the DME. No high performance chip, nor do I plan to install one. 24lbs seems a bit high unless the extra pressure just helps atomize the fuel better. So, if I keep it stock except for moving to what seems to be an improved injector design, what do I need to know about the different pressure ratings?

[ELVA164]

Get the M50 injectors with the part number which ends in 415. Those are the ones for a stock engine. I have a set and they're no real difference performance-wise from the originals (aside from not leaking), but I like the design more for keeping them clean like you said.

[E30Garage]

What he said ^^^

[Three Dee]

Interestingly, when I Google 0280150415 I find that Five-O motorsport lists the 0280155885 injector as the GenIII replacement for the 415, and that it works in all the same applications as the 415.

Just for laughs and giggles, here is a set that caught my eye on E-bay. Problem is, the part number the vendor is using does not match the casting number on the injectors.

http://www.ebay.com/itm/122503830363...witem=&vxp=mtr

[rustneversleeps]

What he said ^^^

Does this apply to 88 325iC M20 with stock rails and harness ...Reason why i ask i have the tan injectors and wondering if i use those blue ones and what the pros and cons for both...And do they tick if there bad..

[Three Dee]

No, I think a nice, regular tick is a good sign. I used my stethoscope to check mine once I got it to run, and I found #6 had only a weak tick, and #1, when it did anything at all, actually made a "clack!" sound. I don't think it's supposed to do that.

[Three Dee]

Hey Elva164! Is that your Lotus-Cortina?

[1SGDHORN]

I just purchased these off EBay for my 1989 325iX.


http://www.ebay.com/itm/111848616307...%3AMEBIDX%3AIT

[ELVA164]

Hey Elva164! Is that your Lotus-Cortina?

Yes, just raced it yesterday actually! Check our website for photos/videos/info about it and our other cars.

[Three Dee]

Yes, just raced it yesterday actually! Check our website for photos/videos/info about it and our other cars.

I'll do that! One (but only one) of the reasons our daily driver is an E30, and why we got our daugher an E30 as a project car is because we like old cars. I've been a fan of the Lotus-Cortina for a long time.

- - - Updated - - -

Well, folks, after looking things over I'll be getting a set of 415 injectors. Not only does your advice make sense, but they seem to be easier to get than the OEM injectors.

[ELVA164]

I'll do that! One (but only one) of the reasons our daily driver is an E30, and why we got our daugher an E30 as a project car is because we like old cars. I've been a fan of the Lotus-Cortina for a long time.

- - - Updated - - -

Well, folks, after looking things over I'll be getting a set of 415 injectors. Not only does your advice make sense, but they seem to be easier to get than the OEM injectors.

I have my E30 for the same reason! And don't worry, the 415 injectors are still Bosch, which was OE for the M50 engine and the OEM for the M20.

[sienayr]

I would be careful buying off of ebay. When it comes to auto parts I avoid it like the plague, as well as Amazon. Perfect fencing operations for counterfeit parts, unless it's a store front for a known good reputable parts dealer.

[E30Garage]

What he said! ^^^^

[Jeffnhiscars]

When SSSquid met up and installed,my chip and 19lb injectors (not to mention doing a street tune) he said that the stock ECU can manage up to 17. Beyond that he recommends a chip.

not that he knows anything about the subject

[rustneversleeps]

No, I think a nice, regular tick is a good sign. I used my stethoscope to check mine once I got it to run, and I found #6 had only a weak tick, and #1, when it did anything at all, actually made a "clack!" sound. I don't think it's supposed to do that.

The reason why i ask is i did the valves as best i could and triple checked to make that the lobes was at the bottom,But now i heard that it could be a bad injector...And when i did the screw driver trick to here with your ear i here that tick in the middle of the valve cover close to the injectors #6 and no tick around #1 and #4.....

[Three Dee]

I got the 280150415 injectors earlier this week. Once warmed up, the car runs GREAT!!!! However, a cold-starting issue is still plaguing me. Sigh.... I think old age (the car's, not mine!) has something to do with it.

I suspect a dying IAC. Cleaning it hasn't helped.

[ELVA164]

Broken record, but next step should be a smoke test for vacuum leaks. That can keep you from chasing your tail with other parts.

[Three Dee]

Broken record, but next step should be a smoke test for vacuum leaks. That can keep you from chasing your tail with other parts.

Been thinking about that. Is a smoke tester something I can rent or borrow? I may not be the most skilled mechanic in the world, but I really don't like turning one of my cars over to a mechanic unless it is something I absolutely cannot do myself.

[ELVA164]

I honestly don't know, but it's a simple enough procedure that if you go to an independent guy he may be willing to do it with you there so you can see how it works. It doesn't take very long to set up or perform.

[Three Dee]

I honestly don't know, but it's a simple enough procedure that if you go to an independent guy he may be willing to do it with you there so you can see how it works. It doesn't take very long to set up or perform.

Thanks.

For what it's worth, since it doesn't look a like a great deal of pressure is involved, I've toyed with the idea of making a smoke test machine with my old CPAP machine.

"Toyed with" being the operative phrase here.

[thejlevie]

You really need to use a real smoke machine, which produces persistent oil smoke. While you can build one like the pros use, you'll spend more in parts and fabrication that having a shop run the test.

[Kershaw]

That may be, but you can build the machine on a Sunday morning at your house drinking a beer instead of wasting 4 hours waiting at a shop on a Wednesday morning and have to take PTO to do so.

[Three Dee]

Since I've been busy piddling around with other stuff, I haven't even had the chance to look into getting access to a smoke machine, so yesterday afternoon I just did a visual check of every thing. I found the hose connecting the ICV to the intake is getting to be in bad shape, so just to see what would happen I put a clamp on the end that is cracked (YES, this is a temporary fix!!) I also took off the throttle body so I could do a better job of checking the hose that runs to the charcoal canister and remove and check the crankcase vent hose. Those hoses checked out okay, but in the process of doing all this I lost the cap I had put on another vacuum fitting (part of the mess running to the brake booster). I put a temporary plug in that fitting.

Oh, and while checking everything out I discovered I had the engine management temp sensor plug connected to the temp gauge sensor, and vice versa.

Once I got everything back together I fired it up. I still don't like how many times it had to crank before starting, and the idle is still not as good as I would like. I found, by the way, that when I was messing with that fitting that lost the cap, that it ran better than it had been if I simply put my finger over the end of the fitting than it did with the cap, so now I am thinking the cap was too big and not sealing correctly.

So, I'm going to fiddle with it some more. A smoke check is not out of the picture yet. After that, other things that are wearing out!

[E30Garage]

Make your own smoke machine, see vid bellow: or more options here
https://youtu.be/2U5kFib1WxE