Help with understanding alignment of 4x cam and 58x crank reluctor wheels and sensor

[copo-rat]

Any new progress David?

[copo-rat]

VERY tough! I'm having no luck at all with sourcing the same thing! Please share any info if/when you get some. I'll do the same.

It may not be relevant at this point, but I did manage to find affordable engine harnesses on car-part.com! I bought an '08 engine harness for $150

http://www.car-part.com/cgi-bin/search.cgi

[ScarabEpic22]

Good call, looks like there are some 06-07 I6 harnesses that might fit the bill of what Im trying to do. Have to wait until June after I start work!

[gmh308]

MAP readings seem to be pretty high.. I'm seeing ~85kpa @ 1500rpm - 102kpa key off (I'm at sea level). Thoughts on that?

Thanks all!

-David

102kpa is pretty normal for a nice day at sea level.

[gmh308]

It may not be relevant at this point, but I did manage to find affordable engine harnesses on car-part.com! I bought an '08 engine harness for $150

http://www.car-part.com/cgi-bin/search.cgi

An 08 what?

[S10Wildside]

Well said... If EFI Mike wanted to chime in, he probably would have by now. He has too much time and money in R&D just to give it away and I completely respect that. His innovative ideas have led us to think outside the box - basically, this thread would not exist if it was not for that. Thank-you Mike!

Sorry guys, I didn't know this thread existed. I don't have much time lately to look in the forums.

Revealing R&D information is unrelated to buying $4K worth of parts, but it is related to purchasing something that requires it. A PicoScope was purchased intentionally to play with the various waveforms. It would be silly of someone to suggest that R&D information has little value when thousands of dollars are spent on engine(s), laptop, scope, EFILive, time spent with R&D, and so on....but there are those occasional phone calls and email that put no value on this sort of information.

I'll avoid a tangent about all of the costs associated with CNC'd parts, the relatively small market, and the complaints related to pricing. What many don't seem to get is that they are receiving so much more than what they paid for. Okay, I'm done.

Related to the 58x stuff and cam signal, this is what I wrote in the installation guide:

The Gen IV LS engines have a fixed cam signal with no adjustments, but the EFI Connection 4x distributor assembly allows 360 degrees of adjustment. We have found that the best orientation is as shown while number 1 piston is up.

The engine will start and run with improper cam signal alignment in relation to crank signal. When the signal is in the incorrect position, several things may occur…
• The ECM sets a P0016 DTC that indicates the improper crank/cam correlation.
• Extended cranking until the engine starts (ECM assumes improper stroke).
• Backfire during cranking (ECM assumes improper stroke).

Because GM provides no information regarding proper alignment, our recommendation is to roughly set the cam signal as mentioned above and then monitor for P0016 and poor starts. Adjust the cam signal until P0016 does not set and the engine starts without backfire or extended cranking.

My to-do list includes grabbing a scope trace of crank/cam relationship from a Gen IV engine. Haven't done that yet. It hasn't been necessary for SBC/BBC installations, but I want to include it in the installation guide.

I've been successful in convincing nearly all 58x inquiries to go the 24x route. Most peope are not DIYers and don't have the skillset or equipment necessary to perform a successful and reliable 58x conversion. Much of this is related to crank/cam orientation, the price of parts, and the learning curve of the Gen IV ECMs.

Everyone contributing to this thread is capable of a 58x conversion...there are not many out there like you.

[S10Wildside]

It's been awhile since the 4x cam reluctor R&D, but I do recall the signal being a little fussy when Bill cut the teeth on the Bridgeport. The first prototype had uneven pulse width, but the ECM didn't mind. The second prototype looked better, but the ECM had issues with it. I think it threw a DTC we couldn't avoid.

Here's a little insider info...for the sake of showing you how accurate EFI Connection's 4x cam reluctor is. This is how we got it right.



And after we got it right, the bottom side was milled for balance to evenly distribute the rotating weight.

[copo-rat]

An 08 what?

Sorry about that, an '08 Trailblazer (I6) engine harness. We were talking earlier in the thread about how hard they were to find.

[NateP]

Amazing work!!!

Any update on this?

Did you end up using the 14 tooth count for the crank? Ever figure out the cam?

Thanks

[schwoch1]

My project hit a standstill as summer approached, darn wife scheduled 99% of my free time away with family events, vacation, etc....
If I Had more info at this point, I would talk... but at this point.... I have nothing!!!

Mike