91 GSX Build (Good enough to beat Jobe)

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http://www.autozone.com/autozone/acc...er=974886_0_0_

[seawalkersee]

I was thinking about bule the other day when I thought the only way for the problem was still going to be a sensor or a broken wire. Until you can narrow down a cyl, I think you are just pissin in the wind. How else would it drop a cyl?

SWS

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We pulled the plugs out and number 2 was caked with carbon. Replaced all 4 plugs, as they're cheper than wires, and the misfiring stopped almost completely. We took it out for a run, and it did misfire or blow-out up top right after a shift. Have not diagnosed this issue yet.

When we parked, there was a puddle of coolant, and our engine temps were nearing 205* when stopped. It was clear I had a cooling issue...

Ordered a cheap-o Aluma-Radiator, shroud, and fans for the monster...


Of course they don't fit!

[img][http://a3.sphotos.ak.fbcdn.net/hphot...907_o.jpg/img]
Had to re-mount the FMIC as well to give more clearance for the shroud. Dreading the day I blow a cooler pipe.


Solution was to mill a larger ID ring on the shroud, and trim the fan enough to sink it between the shround and the radiator. All systems are go.

Doing some initial runs, everything appeared to be kosher. Radiator temps stayed under 190* our entire trip. I still need to take out some more fuel, and add more timing.

Jobe, when we going to race?

[ganuolfthegrey]

maybe next year. don't even ask why cause i have no clue anymore.

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Originally Posted by ganuolfthegrey

maybe next year. don't even ask why cause i have no clue anymore.

Get your car back from that glitterfart and we'll help you sort it out. It's not that hard, but you've got to take the first step.

[seawalkersee]

Okay, so it missfires but is running rich? Not a broken wire. Its a broken toon or some sort of bad pressure sensor that is not showing the right stuff. Too lean when it should be fat, and fat when it should be lean maybe?

SWS

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Chris, it seems like a Mechanical failure, as my tune runs the same every time... Some times it does OK, and now, more and more, it is misfiring at about 3500 under boost...

Did check the tune, and found there was a multiplier I didn't know about setting my dwell too high... I think I probalby burnt out a coil.

Went to Pick'n'pull to see if I could find a replacement coil for cheap. No luck. I did find another 1G Auto AWD transmissin, transfer case, and intermediate shaft for $300 though.

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Dual 4n25 opto-isolator circuit.... The side on the left is pulled up to 5v, runs through the input side of the opto, and has a switched ground at the cam/crank sensor (Jumpers connect to the pins on the edge of the board)

Current is limited on the other side by a 4.7k resistor, which T's off to a 1k pullup resistor heading towards the output. The other side of the T flows through the collector on the Opto's internal transistor, Emitted to ground.

When the CPS/CAS hits a "Tooth" (missing hole in the wheel), it supplies ground, which allows the opto's internal LED to illuminate, turning on the transistor and bringing the other side to a 5v logic low.

I'm going to have to make a new sub-ecu to hold all of this junk :/

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Switched to a higher resolution Cam/Crank wheel because the car kept running so poorly. There was all kinds of timing error before... When you looked at the cam gears with a timing light, it was all ridiculously off and fluctuating like crazy.

If you look at the bottom wheel in the picture, you can see why... The outer set of holes (4) is the crank position, where the inner set is the cam. This rotates at the speed of the cam, so you're looking at two crank rotations... That's two crank positions every rotation, top and bottom... Not the greatest to predict by...

With the new wheel, I have 12 points to modulate timing from on each rotation... This made the timing error drop significantly, however, the car is still misfiring... I've converted it over to a very hot running Ford ignition cool too, and that did not help.