Update on my detonation post, more info needed (PCM tuners imput please)

[HBHRacing]

for the ones that followd the other detionation post I made http://www.camarov6.com/cgi-bin/ulti...;f=16;t=002658


Ran a back pressure test on the cat, came back normal. Everyhing was normal. did the top engine clean and no help there. Today I was going to swap the ign control module and found out that I grabed the wrong one from our part store (boxed wrong) but we also threw on 2 new coils for the hell of it.

after taking a testdrive with the scanner hooked uop here is what I noiced. The PCM is swicing back and forth between open and closed loop. After about one minte it entered closed loop as normal. Then while driving part throttle it wouold enter open loop for a random amount of time.

My questions are.. I know that under WOT the pcm will enter Power enrichment mode, but will the computer switch to open loop or maintain closed loop operation and just go to the pre programed fuel maps for PE mode?

also on decel it would go into open loop for a long time. I know that decel has a different cell but I was not aware that it would also hit open loop then??

And the last thing. Is there any reason that under normal driving it should be hitting open loop. I am talking on acell and not WOT at random times.

Thanks a lot everyone

[tdaddyz]

he still has the 160* thermo right? if so, without a resistor to trick the pcm i believe it will try to stay in open loop

[HBHRacing]

even so.. with a heated 02 and engine temp always 175 or higher tat can not still be correct? Even when the temp was reading 208 it was still swictihng back and forth

???

[ReodDai]

Originally posted by tdaddyz:
he still has the 160* thermo right? if so, without a resistor to trick the pcm i believe it will try to stay in open loop

This means the computer is confused and trying to stay in open loop. Regardless of what the temps are the computer is getting an incorrect signal and trying to commodate. Try replacing the thermo with a 180, adding the resistor or putting the stock one back in (if you have it).

[L32Projekt]

One thing I noticed is that you stated in the other thread your friend may be running NGK TR55 spark plugs. Why? They're gapped stock at around 0.055" and are 1 heat range colder plugs. Unless he's running increased compression or FI on his car there's no need for them. Get stock AC Delcos and slap them in, go from there...

[tdaddyz]

Originally posted by L32Projekt:
One thing I noticed is that you stated in the other thread your friend may be running NGK TR55 spark plugs. Why? They're gapped stock at around 0.055" and are 1 heat range colder plugs. Unless he's running increased compression or FI on his car there's no need for them. Get stock AC Delcos and slap them in, go from there...

the ngk tr55s are what he needs, your thinking of the tr6's

[HBHRacing]

closed loop starts at about 140 degrees acording to the timer in the PCM. hover the timer will be over ruled when the 02 reaches temp prior to that (which it always will when the heater is working correctly. It takes less then a minet to heat the sensor to enter closed loop. there is NO WAY that a motor running 210 can be calling for open loop unless there is a map in the PCM whitch will alow for it and to my knolwagle the temp for PCM closed loop operation is 140.


EDIT: and yes TR6's are colder and usualy used for spray or boost aplications. even so witha detonation if he was running TR6's it would be a good idea

[ September 05, 2004, 10:16 PM: Message edited by: HBHRacing ]

[Turbo V6 Camaro]

in WOT the O2's do jack, if it falling in and out of loop the PCM is getting a signal that the car is not warm and advanced the timing, so if indeed the car is hot and its advacnes the timing there is your knock problem. are you only getting knock in open loop? im willing to be that yes you are.

i would monitor the O2's i think one of those is sending a faulty signal and the PCM throws the car in Open loop.

[HBHRacing]

ok.. I'm asking simple questions but getting no answers for them. Everyone is just boucning into different things..

-----------
I know that under WOT the pcm will enter Power enrichment mode, but will the computer switch to open loop or maintain closed loop operation and just go to the pre programed fuel maps for PE mode?

also on decel it would go into open loop for a long time. I know that decel has a different cell but I was not aware that it would also hit open loop then??

And the last thing. Is there any reason that under normal driving it should be hitting open loop. I am talking on acell and not WOT at random times
-------------

That is all I need to know. If you read my first post closely I know that in WOT you enter PE mode and 02's are ignored. The map in the PCM will take over fuel control but what I need to know is if in PE mode the computer wil set into open loop. I do not think it does.

I also need to know if in decell will it switch to open loop. again I do not belve so. I know that the fuel statagy will enter a different cell but I belive that it should not swich to open loop.

now. disregaurd everything about the detionation or anything other then closed loop operation and you will see what I am asking. I understand a lot of how the PCM works but not al of it. This is why I asked for help. I wanted him to go just short of WOT and see what happened. and he did and we got open loop randomly. a ot of times on acell still not in PE mode we get open loop. nomal driving on the highway at random we get open loop. see what I am getting at? I think my questions are being over complicated.

Think of it this way. if your car with a 195 thermo was running 210 after about 5 mins of startup and been in closed loop a while and you were normaly driving and it swithed to open loop you would know that there was a problem correct?

[Turbo V6 Camaro]

oh i see now

my car stays in closed loop unless it is shut off for a few hours, at about 160-170*ish it hits closed and even thou my car balry hits 180 any more it stays in closed loop all the time,

i have a M5 and most of the time when i decel i just put it in Nutral and cost/brake it stays closed loop. in down shifing im not sure but i NEVER rember seeing open loop while driving.

BTW this was using a 6K MAC scaner the will scan any car

[HBHRacing]

yes. thank you. I hope my last post didn;t sound to canky. I had just woken up and was headed to work. Thats exactly what I am talking about. I see no reason why it should be entering open loop after warm when coolant temp is up to over 210 most of the time. I guess what i need are some PCM programers to confirm this and make sure that it is indeed a bad 02 sending a bad signal to the PCM. Or if it might be a PCM, ECT or wireing problem even tho th PCM was just replaced by teh dealer.


and I was scanning using the $9,000 + snap on M.O.D.I.S. scanner that I use at work [img]smile.gif[/img]

[Turbo V6 Camaro]

and I was scanning using the $9,000 + snap on M.O.D.I.S. scanner that I use at work [img]smile.gif[/img] [/QB]

take my mojo :(

;) [img]tongue.gif[/img]

[L32Projekt]

Originally posted by tdaddyz:
</font><blockquote>quote:</font><hr />Originally posted by L32Projekt:
One thing I noticed is that you stated in the other thread your friend may be running NGK TR55 spark plugs. Why? They're gapped stock at around 0.055" and are 1 heat range colder plugs. Unless he's running increased compression or FI on his car there's no need for them. Get stock AC Delcos and slap them in, go from there...

the ngk tr55s are what he needs, your thinking of the tr6's </font>[/QUOTE]We use NGK TR55's in out L67's for one heat range colder, TR6's are TWO heat ranges colder...

EDIT: Yup, the 3800 Series II non-S/C uses the same stock plug as the L67, but the TR6 is considered to be two heat ranges colder.

[ September 06, 2004, 09:39 PM: Message edited by: L32Projekt ]

[Jason McCallister]

would monitor the O2's i think one of those is sending a faulty signal and the PCM throws the car in Open loop

Maybe I'm totally out of line here, but I do not believe an O2 sensor will throw the PCM into open loop mode after warm-up.

I would check your TPS (Throttle Position Sensor) to verify it is working properly. It is possible the contacts on the potentiometer are dirty and/or shorting sending a "100% throttle" signal to the PCM.

[HBHRacing]

well. yes. a faulty 02 will put the computer into open loop. It is number 1 in controling open and closed loop.

and TPS is fine. It;s not the same as teh standerd TPS's that your used to there are actualy 2 of them. one at 5 volts woring down and 1 at 0 volts working up. Besides. if TPS was reading 100% the car would not start due to being in clear flood mode