I scanned a buddies 94 forumla yesterday to see what was wrong with it, using Datamaster EE. Biggest issue was a dead left bank O2, which was no problem to fix. But then the car was running really rich (idle, couldn't check while driving because laptop battery wouldn't take a charge) to the tune of 108/108 LTERMS and 110/114 STERMS. He told me that it had an aftermarket maf on the car, so we located a stocker with thunder ends to use and that cleared up the rich problem. It started running at 120/128-9 and 118/126 at idle. That's perfectly liveable.

BUT! For some strange reason, the knock counts were just wacky. Always red, always cycling. Never stopped. Just would count up and up until it topped out and cycled again. This is all moving VERY fast too, as in you only see numbers in the 1,4,8 thousands. The car is pulling upwards of 6.4 degrees of knock retard at an idle rev, and while driving breaks up above about 4000 RPM.

Has new plugs, wires, coil (coil wire is EXTREMELY long though), fuel filter. Everything else checks out.

Anyone have a clue as to why the knock counts never stopped cycling, and do you think a LT4 KM would help?

 

I have heard about some 93s having spark retard(false) issues for some reason. Like they would read knock even with the engine off.

 

What you're thinking of is if you're logging in Datamaster and you shut off a 93. The knock counts will count up and max out once the motor is off. That's normal.

On this 94 that I scanned, it's just cycling all the way up and starting over again.

 

Oh. Is it pulling max timing due to the knock? What would happen if you disconnect the knock sensor? The car wouldn't like it but what would the counts do?

I would put the aftermarket MAF back on, adjust the injector constant to get a good blm and drive it again to see what happens then. If counts go away, then somehow, the Maf is involved.

I would also disable knock retard(only if you are sure it isn't real) and see if it still breaks up over 4. When I had extreme false knock, the car would lose lots of power but it wouldn't break up. Sounds like something else is in the mix.

 

Well, the MAF was definitely in play because of the LTerms. He's in the process of locating a stocker. It was pulling upwards of 6* of retard on a hard neutral rev with or without the stocker MAF though.

I'm thinking it's going to be false, just for the fact that I thought I heard something rattling around in the exhaust. The car has RK Sport headers, an ORP, and a stock cat-back. He just hasn't been able to get under it and see if anything is loose.

He's also ordering a LT4 KM so that should help out some I would think.

 

My car will pull timing if I neutral rev it too. But it won't while making a pull. Probably beyond control without severely desensitizing the ks.

I would be looking at why it wants to break up at 4 grand.

 

Keep the stock MAF, obviously the aftermarket was giving you problems. besides, those things usually do more harm than good, unless abdolutely needed.
As for the knock. If I had a constantly cycling knock that just stopped at around 4000, the first thing I would suspect false knock. One way or another a LT4 Knock Module couldn't hurt.

 

He says he is looking for a stock one.

Also, the knock count doesn't stop at 4000, his engine breaks up around then. Like you said, I would definately try an LT4 km.

 

I actually can't specifically attest to that. No laptop with a battery and no working cigarette lighter = no driving while logging unfortunately.

 

Perhaps I am misunderstanding the term "breaking up"

what exactly do you mean.

 

Simply defined: Misfiring, popping, ect.

 

Well, that changes everything.

Sounds like a hi-res problem. did you get any other codes? Does this car have any modifications to the ignition?

Last I heard, Deltec is working on a device to count ignition pulses. Until then, without a light, theres not really any way I know of testing it other than to pop it open and look for obvious problems. You could give them a call and see how far along they are.

 

Not throwing ANY codes except for a Skip-Shift circuit.

 

Thats strange. have you tried pulling off the map and running it in speed density mode?

 

Haven't tried that.

Just curious, but does anyone KNOW what a bad Knock Sensor or module would look like on a scanner?