Bosch 42lb Green injectors maxing out around ~10psi?

[tschultz]

With 42#'s on my M30, I was idling at 1.3ms and having some strange behavior near idle. I went to 30#'s and idle around 2ms now. This is at 5300 ft.

I did soem testing on the subject:


I am approximately 300hp when corrected for altitude, but my max boost is at 160kpa and the 30#'s are just over 80% duty cycle at higher rpm's and boost.

This is where i'm at with altitude corrections based on real world testing, but still a work in progress.

[nando]

^ i am also running my coils in wasted spark from the LED. is that actually dodgy though?

nah it's fine.

LS1 coils are a little different, but something to know about the LS2 truck coils - they will auto-ignite if you overdwell them. This leads to higher ignition advance than you expect. Basically, keep them under 2ms.

[e30davie]

I was more refereeing to the fact that mine are cable tied to the AC hoses behind the headlight.

[LowR3V'in]

^ i am also running my coils in wasted spark from the LED. is that actually dodgy though?

[e30davie]

I agree, it's not very pretty :p

But I appreciate that it works, and it cost you nothing. It's like my COP setup - yeah I had to buy the MS3 setup and wire it etc. But the plugs, coils, wires, etc. were dirt cheap (GM stuff) and in those cases, they are miles ahead of the Germans. Who ever heard of a GM LStruck coil failing? Nobody. I had a misconfigured MSQ, that caused the coils to overheat enough that it melted the connectors, plugs and wires to the coils. But those coils are still going strong 8 years later, and I have no idea how old they were when I bought them. Some BMW coils barely last 5 years...

If you appreciate that, you are going to love the other dodgy shit in my engine bay. I too bought 8 x LS1 coils, for $60 aud ($42usd?) found some aluminium and threaded rod in the shed and run these off the LEDs on the MS2. I also manged to overheat them with the incorrect dwell settings. not quite 8 years but a few thousand kilometers. The last distributor rotor i bought was over $100 aud...

photos attached.

[nando]

It shouldn't leak (that would cause vac leak since it's past the AFM, turbo or not), but of course, if yours is stock and 30 years old, well.. anything could happen.

It sucks they cost so much now. I guess I was "lucky" that mine died long enough ago that I could afford to buy a new one, but not so long enough ago that it is completely worn out. :|

If you're running MS of course anything could work. Any 2 or 3 wire PWM IAC would be fine - BMW used them until the Valvetronic engines, which don't need an IAC because they don't use the throttle plate. Or anything from GM, Ford, etc.

Hyundai and Kia actually copy a lot of designs from the Germans, so that's another possible source. The former lead engineer of BMW Motorsports works there now (in case you didn't already know, hah!).

Funny thing about the GM stepper IACs. It's been ages since I've looked at, much less updated my Megasquirt 3 (since at least 2012), but last time I was looking at that stuff, they weren't reliable because the control mechanism couldn't track the position accurately enough, so they would "drift" out of synch. And also the hardware wasn't always good enough so it would overheat. I presume that's all solved now.

My cold idle actually sucks. It holds an "idle", but by that I mean it doesn't actually die - it's not smooth or steady. It's actually really obnoxious, it bounces up and down 500-1500rpm for at least 5 minutes before settling, ugh. But I drive the E30 so rarely now, and I have no intentions of keeping my current M20/Megasquirt, I just haven't bothered to even try to fix it.. it runs and drives just fine once it's warm. I try not to fix what isn't already broken...

Since mine was L- Jet M20b23 i didn't have an idle control valve. I used one from an AU Ford Falcon. Not really sure if you have the engine in the states. Not the neatest looking, but the valve cost me zero dollars from the wreckers and works perfect with the MS2 on closed loop. This way i didn't need to get a different rubber intake boot. Also im not sure the m20b25 intake boot would fit.

I agree, it's not very pretty :p

But I appreciate that it works, and it cost you nothing. It's like my COP setup - yeah I had to buy the MS3 setup and wire it etc. But the plugs, coils, wires, etc. were dirt cheap (GM stuff) and in those cases, they are miles ahead of the Germans. Who ever heard of a GM LStruck coil failing? Nobody. I had a misconfigured MSQ, that caused the coils to overheat enough that it melted the connectors, plugs and wires to the coils. But those coils are still going strong 8 years later, and I have no idea how old they were when I bought them. Some BMW coils barely last 5 years...

[LowR3V'in]

dumb question but have you guys boost tested the stock valve? leaks?
i have acouple but they are kinda bulky.

[e30davie]

Since mine was L- Jet M20b23 i didn't have an idle control valve. I used one from an AU Ford Falcon. Not really sure if you have the engine in the states. Not the neatest looking, but the valve cost me zero dollars from the wreckers and works perfect with the MS2 on closed loop. This way i didn't need to get a different rubber intake boot. Also im not sure the m20b25 intake boot would fit.

[ForcedFirebird]

The stock IAC works great for MS. I know back in my GM days and MS had just come out, it didn't support the GM stepper IAC, so we would use either Ford or BMW PWM IAC's.

[nando]

I do, yes.

[LowR3V'in]

do u guys use the stock valve?

[nando]

yeah, it's still closed loop technically. Like those heated coils used for automatic chokes on carbureted cars from the 1960's. It's just not very reliable or easy to adjust. I'd rather have a manual choke. :p

[e30davie]

How about the L-jetronic m20 from a 323i E30, made until 1985. Fuel injected with a coolant operated wax auxiliary air valve. Though i guess it closed loop of sorts, mechanical closed loop. I have two and both are jammed shut.

Once i put a proper electronic idle control valve and dialed in the settings in mega squirt it made a world of different to how the engine runs. Even when its hot it helps it idle very well and "catch" the engine as it comes down. The PID settings are key to getting it to work well.

[nando]

You don't have to, but it certainly makes controlling idle speed (hot or cold) a lot easier if you have one.

Honestly, not using an ICV is just a hack anyway. If you tried to name one single fuel injected car that didn't implement a closed lop idle speed, I don't think you'd find even one going all the way to the 1959 Corvette..

[turbski]

[QUOTE=

Fraser, you can use the auto tune feature for cold starts. There's another tab in the function "warm up enrichment 1". Start the car on a cold day (of course with the engine cold), and turn on the auto tune - it does a decent job of ironing out the cold starts.[/QUOTE]

probably another new guy question here but... do you have to have an idle control valve to make use of this function?