Crank triggered ignition questions

John Kelly · Post by **John Kelly** » Fri Dec 03, 2004 7:26 am

On my 2.6 upright conversion with a toyota distributor we are getting synch and reference errors, and the engine will just stop as if a switch were thrown after about 10 minutes of running, and won't start again. I'm told the signals from the distributor to the computer are at fault. Impossible to find the information I need to get new pickups for this distributor, so would crank fired hall effect be the way to go? Can you get both ref and synch this way? I would like to eliminate the distributor altogether. I will probably have Fordahl's do the work when I can afford to ...just want to be prepared with the information.

Thanks, John www.ghiaspecialties.com

raygreenwood · Post by **raygreenwood** » Fri Dec 03, 2004 8:46 am

So it seems time related? Either something is changing size/dimension/location....after warm up. Or...is it happening within 10 minutes even after its warmed up? Like...even when its hot...and then it dies, then you re-start and get another 10 minutes?
Its sounds like something is set up for ...possibly a warm up advance rate..that is then cutting you off when the warm-up time has expired. Ray

dstar · Post by **dstar** » Fri Dec 03, 2004 8:57 am

IS he running the injector signal from the cold start injector wire?
It would lose signal after it warms up....

Just a thought from a FI dummy!

Don

Dave_Darling · Post by **Dave_Darling** » Fri Dec 03, 2004 10:03 am

If you take the signal off of the crank, you are going to lose one of your reference signals, I think. I don't recall which is which, but either ref or synch has to do specifically with the #1 cylinder, yes? You'll lose that specific cylinder reference if you go from the crank, because the crank makes two full rotations when the engine goes through one cycle. If you can reference from the cam, or something attached to the cam, then you can maintain a reference to an individual cylinder... But if not, you're only going to have a ref for cylinder pairs, not individual ones.

...I hope I'm remembering the synch/ref thing wrong, but I don't think I am...

--DD

bhowden · Post by **bhowden** » Fri Dec 03, 2004 11:46 am

I am the beginner compared to the experts here but as I understand it, EFI has move away from worrying about which is exhaust and which is compression. The injection is batch anyway so fuel is unaffected and they get around the ignition problem using wasted spark. The upside is that they don't need to sense the cam position so lots of moving parts are eliminated and the only downside is you waste a few milliwats on some sparks that aren't doing much during the exhaust stroke. A missing tooth on the crank wheel indicates where TDC on 1 is.

Brian

Dave_Darling · Post by **Dave_Darling** » Fri Dec 03, 2004 1:22 pm

Well, TDC on #1 or on #3... But some EFIs are sequential, not batch--and those do care about which cylinder is on the intake stroke. Without knowing about John's EFI setup, we can't really tell if it's batch or sequential.

--DD

John Kelly · Post by **John Kelly** » Fri Dec 03, 2004 1:47 pm

Thanks for the replies. It is a Motec M4 which if I remember right can be set up for sequential or batch fire???

Ray, my computer guy looked for anything to do with a warm up signal problem, and did not find one. There was a time that the engine was running for a while at high rpms during idle, then suddenly dropped the rpms in half like a switch had been thrown....so that seemed a logical thing to look at. We also thought something might be wrong with the pickups in the distributor, but they tested out alright. The car will not start for at least an hour after this happens and the oscilliscope shows no synch or reference (I forget which). I'm at a loss. Hate to just throw money I don't have at it.

Might have to see about getting the distributor I have converted to hall effect and going with a crank sensor as well. The engine is really something when it's running!

Thanks, John www.ghiaspecialties.com

Post by **Piledriver** » Fri Dec 03, 2004 4:13 pm

I have seen many hall effect switches that are temperature sensitive...
Common failure mode.

(Hmm. Maybe that guys issue with the Westy... Won't start hot.)

Can you just drop in a late wasser distributor for your app?
(possibly just for testing, assuming your EFI is really an EMS and does ignition...)

John Kelly · Post by **John Kelly** » Fri Dec 03, 2004 6:04 pm

It is not hall effect...yet. No distributor that is without two magnetic pickups (one ref, one sync) will work for my application.

John www.ghiaspecialties.com

raygreenwood · Post by **raygreenwood** » Fri Dec 03, 2004 7:05 pm

Wait....something is sparking in the memory here. You may have some signals unaccounted for. Things that can cause it to be unstartable for an hour....are either rollover sensor, inertia sensors.....and CHT that is either reaching the resistance level of high limit....or has inherent resistance that is already too high to handle the rise. You may be getting a limp home signal that is misinterpreted. Ray

John Kelly · Post by **John Kelly** » Sat Dec 04, 2004 5:02 am

Hi Ray,

Would any of that show up on laptop diagnostics? nothing like that popped up as I recall.

This very same set up, before the upright conversion, had a similar problem only once. The previous owner simply unplugged the computer and waited a bit, and it started right up.... that's not working for me.

John www.ghiaspecialties.com

Wally · Post by **Wally** » Sat Dec 04, 2004 7:06 am

John Kelly wrote:, so would crank fired hall effect be the way to go?

Well, that would cure a lot of gueswork. The Motec should be able to handle that.
Be very sure that your crank position sensor is mounted super rigid.
I did it like this:

Walter

Post by **Tom Notch** » Sat Dec 04, 2004 7:36 am

John, can the ignition portion of the ECU be turned off? And can you then try a regular ign. system?

John Kelly · Post by **John Kelly** » Sat Dec 04, 2004 7:59 am

Wally, Thanks for the picture.

Tom, I don't know if that can be done...might be a good idea for testing...thanks!

John www.ghiaspecialties.com

paul_f · Post by **paul_f** » Sat Dec 04, 2004 5:06 pm

Wally - have you got any pictures of the back side of the pulley?

How did you attach the timing wheel to the pulley

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Crank triggered ignition questions

Crank triggered ignition questions

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