killav

What Victor says above is basically all that Sean and I did on our short trip. We adjusted the idle and light cruising range cells so that the car would run well enough to get him home by observing the NB sensor readings. The car was running well in my opinion. Sean did not get on the car at all, I would venture to say not past 1/4 throttle.

What Sean and I were seeing after re-start attemtps, was no inector firing at all. Plugs were dry, very dry with no fuel smell. We stuck a screw driver to the injectors, and they were just dead when cranking the engine.

What I saw on the ST, when selecting 36 pound injectors, was that the base fuel map idle cells were in the +120 range and the idle was still poor and lean, with not much room left for enrichment. Moving the injector size numerically down to 24 or so, allowed me to get the idle cells down to around plus 20......and the idle was much better. We did move the cranking pulse width down to about 2.8 after it would not re-start per Jim C.'s advice over the phone......but the injectors just refused to squirt.

OBehave

Crank sensor or cam sensor / harness maybe freyed,cut loose corroded?

SeanR

New, new and fine. You won't get fuel pump to run when cranking if the CPS is not working and we have great fuel pressure.

Again, as Mike said above, there aren't any injectors firing most of the time. It's very intermittent. There is power going there but not enough to fire them off.

Pulse width was changed from one extreme to the other and I was able to smooth out the idle.

I'm waiting on a new PEM to show up in a few minutes, going to stick it another LH and try again. Will update as I progress. Thanks for all the advice.

killav

Sean,

We are going camping north of you at Ray Roberts this weekend. If you don't get your car going by Saturday, I will come over to your house to help. I will bring Roger's Shark tuner/wide band O2 set up as well just in case.

I am really thinking you should swap injectors back to your stock injectors and throw in the stock LH bin file if the new PEM doesn't work, and see what happens.....

Edit: I will come over and help regardless....

victor25

Sean,
could the 18.1 resistance on the injectors be causing the electronics to overheat and or create some issue? If current plan fails, Mikes plan is good one for eliminating stuff. If you put the stock injectors and brains back in the car, it will run with the supercharger on it (or you can just bypass it). If it doesn't run then it has to be in the wiring some where.

SeanR

Ok, here's an update and some odd things.

New PEM in my other brain. Same things went on so I started to think about what I was told and did the exact opposite.

Injectors set at 35.8
Opening sec at 2.32- If I set this any lower, the idle stumbles and is rough.
Cranking pulse now set at 4.85 and it restarts every time, no hic-ups. I pulled the cranking width down to 1.25, 1.5, 2.0, 3.0 and it will never restart but put it up in the mid to high 4s and it works just peachy.

Going to go for a drive in 30 or so minutes and will sit here clicking F5 until then.

victor25

yea haw.. sounds like your making good progress now.

Well I would say after this you will have the whole sharktuning thing figured out.

SeanR

I knew there would come a time when I absolutely needed to learn it, I've only been putting it off for a couple of years. No excuses now.

Thanks for your help and patience, now to understand the "whys" of it all.

killav

This is very interesting. That is a high cranking pulse width. I would have thought it would flood for sure at that setting with 36 lb injectors. Your weak node light that you were seeing from the injectors trying to fire could be over-ridden by that high cranking pulse width......maybe the LH does not like the 18 point something impedence of those injectors???

SeanR

Pretty much the way I looked at it. Drop it down and the noid doesn't light up much, expand it and boom, it's bright.

victor25

I am thinking those are some really really slow opening injectors. That explains why it would run better at the smaller 19lb /24lb injector size settings, and why you are getting the numbers you are. What are your numbers at in the map around the crosshair when idling? They should be close to zero and not a big plus or minus. If they are, then your opening time still needs to be adjusted a little.

SeanR

I moved them all to the zero zone and then adjusted more. Sort of went back and forth. They were in the -20 to -40 range with a few 3, 10's 15's in there too.

victor25

Yes happy you got her rockin

Here is what the base map looks like that I loaded originally and is now gone. Yours will probably look a little different once you get her dialed in, because of your different injectors, but it should give you an idea of what I was talking about on the phone.

John Speake

The LH ECU isn't going to be sensitive to injector impedance anything from 15 to 20 ohms will be fine.

I can't think of any reason that the injectors weren't being fired unless for the usual kinds of reasons, i.e. no rpm pulse at pin 1 of the LH ECU.....short on injector harness..... when the injectors were not firing, did the tach respond normally while cranking ?

Victor may be right about the opening times being very long, I suppose that as the pulse widths were reduced when you increased the selected injector size, then you could get to the point where the injectors just never open during the pulse....

Hilton

As a data-point what are the injectors and their part number?

Finding info on pulsewidths and opening times here on rennlist (or most other places) provides scant info and putting those details in may help others