cross counts

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DynamicGN

New member
I just installed a scanmaster 3 on my syclone. If the cross counts go up slowly (about one or 2 digits a second) does this always mean the o2 sensor is bad?
 
Pau Hana

Pau Hana

"But, officer........."
Re: cross counts

Probably. On my GNs, cross counts would cycle fairly rapidly unless at WOT.
 
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DynamicGN

New member
Re: cross counts

Thanks...yeah I'm a GN guy too. I'll change the sensor and see what happens...I'm getting 8 degrees of knock too at WOT so I gotta see what that's about.
 
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TeeTopZ

Member
Re: cross counts

Don't go wot anymore until you figure out the knock. The syty motor isn't near as forgiving as a turbo buick. You will grenade the motor, not just blow a head gasket
 
Pau Hana

Pau Hana

"But, officer........."
Re: cross counts

At WOT, you're in open loop and the sensors are not in play- your knock is coming from something other than a faulty O2. The O2 is talking to the ECM during closed loop only.Check the basics- fuel pressure, fuel quality, timing, etc.
 
dgoodhue

dgoodhue

BuSTeD 4.3
Re: cross counts

Cross counts under normal driving should always be going up. If the O2 sensor was stuck (or the engine running rich or lean). The cross counts would not go up. At WOT the O2 sensor should be high (900mV +) so the cross counts would not be going up.
 
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DynamicGN

New member
Re: cross counts

The ultimate chip is set at +0 degrees timing...what's the stock timing supposed to be set at...also is it adjustable only at the distributor.
 
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DynamicGN

New member
Re: cross counts

Ok for a quick update. Balancer was fine...I set the initial timing to 0...although, I couldn't see what it was like before, I know it is set correctly now. Still getting knock even right as I'm getting in to it...I really don't even get on the boost much, maybe 5 psi before I let off, knock goes up quick, 8 - 10 on scanmaster. I hooked up tunerpro for the first time. I'm new to this so I'm not sure what I'm looking at. I see spark advance timing at 23.2...is that too high? If so, how do I reduce that? I have a file of idle if anyone wants to see it...also, after I changed the timing and reset ECM, I noticed that my intercooler pump comes on at key on, it never did that before....not sure what's going on here?? Any help would be greatly appreciated. Thanks.
 
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Ross L

Member
Re: cross counts

If you haven't already. Replace cap, rotor and plugs. Then add race fuel if you still have knock to find out if its "false". IMO:2cents:
 
MadMike

MadMike

Member
Re: cross counts

And u can do the xylene trick to see if it fueling/timing issue vs mechanical knock noise. .. like hard plumbing lines bouncing against steel...
 
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DynamicGN

New member
Re: cross counts

Did the tune up about 1k miles ago when I bought the truck and had all that changed...the truck has 59k miles. It has the ultimate chip as well. How do you adjust timing with that chip? Shouldn't it be lower? I'll add race fuel next.
 
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DynamicGN

New member
Re: cross counts

Knock went down significantly with C16...I'm getting under 2 degrees...it saw 4 degrees but it was at a shift...this is much better now that I'm able to go to 15 psi with 0 - 2 degrees....so my new question is, what do I check next? Not sure what injectors the truck has...they are red.
 
0966Sy

0966Sy

Code what?
Base fuel pressure should be checked, and WOT fuel pressure. The ultimate chips where designed around 50psi base. You should be getting an increase of 1:1 after base fuel pressure. Base 50psi, 15psi you should have 65psi
 
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DynamicGN

New member
Re: cross counts

Got it...I'll adjust it tomorrow. ..am at 40 psi in park line on...I'll raise it to 50 and update. Thanks.
 
0966Sy

0966Sy

Code what?
DynamicGN said:
Got it...I'll adjust it tomorrow. ..am at 40 psi in park line on...I'll raise it to 50 and update. Thanks.
Click to expand...


Sounds like your already there, vac line on the regulator you will be about 10psi less than base. Base is measured with vac line off the regulator. Do you know what program ultimate chip it is?
 
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DynamicGN

New member
Re: cross counts

I misread it...it was set at 36 psi line on...took it off, it went up to about 45 - 46, then I adjusted it to 50...the box says T115. ..I haven't tested it since I raised the fuel pressure, will do tomorrow
 
D

DynamicGN

New member
Re: cross counts

OK I'm still getting up to 4 degrees knock...I don't think raising the fuel pressure helped much...I'm also afraid that once I use 93 octane again the knock will be much higher like it was before...not sure what else to look for....
 
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