Troubleshooting a miss, etc

[Steve Wood]

It goes to batch mode, but it should still run well...but...d id you go drive the car with it plugged in after rotating the sensor?

[Steve Wood]

btw, are you sure you installed the sensor properly and not 180 out?  usually they run pretty badly when 180 out, but sometimes they run fairly well

[TurboCajun]

no I havent, I didnt trust running it with all that noise it made after I unplugged it

[Steve Wood]

it should not make noise, but, anyway, I wanted you to drive it with it plugged in after you rotated the sensor?

Something sure sounds wrong, tho...in batch mode, it sprays half the cylinders at a time rather than individually.. .used to be an old trick that we unplugged the sensor when we raced because we thought it might give us more fuel...that was long ago.

you mean the cam sensor had more than a quarter inch of play up and down?

[TurboCajun]

sorry .035 in

[TurboCajun]

I am pretty sure the sensor is set right.

[Steve Wood]

did you drive it after you turned it?

[motorhead]

I shimmed my cam sensor years ago; I had to rape a few SBC distributors to get the shims. I don't remember the final tolerance once shimmed but it was a significant improvement.

With respect to the 180*-out issue I was reading in this month's GMHTP that they had "lag" issues which they attributed to the cam sensor being installed incorrectly. Evidently after they put the Caspers cam sensor tool on the car and got it sorted out the car woke up. I am not sure if this is just more magazine snake-oil I was exposed to while sitting on the crapper or not?

[TurboCajun]

ok went for a drive, didnt feel any difference when in throttle but at idle it was very rough. hooked the cam sensor back and went for another drive first gear felt good but when i hit 2 it feel on its face and i got 13.9 knock. so i came pack home and parked it, slammed the door and tought about kicking the outside but i didnt want to hurt my foot, sorry i am just upset guys

[Steve Wood]

Okay, first thing I would do is put the car on TDC, then rotate the crank so the balancer is at 25 ATDC.  Then remove the cap and see if the sensor is positioned as shown on my site.

Before you put the cap back on, clean the inside of the cap, magnet and all, with some alcohol to get any dust off and out.

Either it is not set correctly, or you have a related problem.  It should run very well with the sensor disconnected.  You can come drive either one of my cars and I challenged you to tell the difference.

If it is properly set, then I would wonder if the balancer ring is slipped, or such

Relax, cars, boats, and women are all designed to piss you off. Borrowing them is always better than owning them.

[TurboCajun]

will check tomorrow,

[TurboCajun]

just in case someone else has been following this thread, re-timed the cam sensor and still had the same issue, now Steve was kind enough to send me a cam sensor to try to compare, still the same issues, Steve and I have talked and have desided to try a different ECM, it is on order at the moment. I have also ordered another cam sensor cap as I cracked mine, and will be sending Steve's back to him. I will update when I change the ECM.

[Steve Wood]

Keith, we need to be prepared to swap the module if the ecm does not fix it...

[ULYCYC]

Before you install the new ECM try this, Pull off all the plugs on the ecm. Check with ohm meter that all values are over 20ohms between:
 A6 to A2
 A6 to A3
 A6 to A4
 A6 to A7
 A6 to C1
 A6 to C2
 C3 to C4
 C5 to C6
 You are checking at the plugs NOT the ecm. This will check all the wiring to the ecm first. (ecm removed)


I also check the pinout's on the ECM. If you can't read this I sent a copy for Steve' webpage a few years ago.

[TurboCajun]

i will check all, Thanks