car is running weird

[06silverbullet]

Without codes or abnormal engine data it's pretty tough to even hypothesize what "could" be wrong or where/what could be the cause of the problem. There's been some pretty standard suggestions "clean MAF/TB" and check the datalog for anything that may stand out. Just because the car may be setting a new threshold for what you consider to be running rough, doesn't mean that it isn't just learning how to run again. Hell just the weather could be enough to throw off the baseline in closed loop. Depending on how modified, the worse it could be. Until it pops out some codes, I'd just give it the chance to learn. Now if you take it out and do some WOT pulls and it runs like shit, then I would be concerned. Something would have to change fairly significantly to throw off open loop.

i took it around the block before i replaced the altenrator and got on it a couple times adn it was gutless

if i take it out tonight i will try and record it with my phone

checked all the plugs and they looked fine, none were fouled or wet.

 

[06silverbullet]

put a good few hot laps on it wot pulls in 2nd 3rd 4th drove about 20 miles, car is running lean as hell for afr in the 13's

 

[TexasBlownV8]

what do i capture? settings? and yes the 02 sensors were unplugged and i did replace one that had gone bad recently a couple months ago. it was also the main o2 sensor, but that would have thrown a cel considering mine was just delayed on warming up and it threw a code.

i may wait til tonight and try crusing on the freeway for a little bit but i doubt thats going to change anything but would finally rule out the tune issue but i highyl doubt thats it

i getting really sick of this damn car, between last years engine harness frying and now this shit... getting over it and quick. miss my fucking 97 tbird atleast the damn thing ran no matter what

Sell me the damn car for cheap then!

 

[06silverbullet]

Sell me the damn car for cheap then!

lol car is pissing me off but i dont want another one... i hate that

 

[TexasBlownV8]

yeah i know. just gotta figure it out. Do you have a datalog config file to use from Manuel?

 

[06silverbullet]

yeah i know. just gotta figure it out. Do you have a datalog config file to use from Manuel?

no i don't i sent him a pm earlier.

i tried the stock tune and it still ran like shit, slapped the astock intake on but left the rest of the bolt ons on

 

[BruceH]

no i don't i sent him a pm earlier.

i tried the stock tune and it still ran like shit, slapped the astock intake on but left the rest of the bolt ons on

Do you know what your fuel trims are? You can log them via the handheld or with livelink.

Why fuel trims you ask? They can point to a few things that might be happening because they correct a/f in closed loop from what's predicted to happen based on airflow.

If the trims are out of whack it means the fueling is off. If we can determine that fueling is off it helps to narrow down what's going on. An example would be excessive positive trims. This could mean that unmetered air is present and it's being compensated for with the fuel trim.

Trims should be within 6% (.06 for the log, 1.00 is 100%) in an ideal situation. If you somehow swapped the o2 sensor connections then the ecu would be correcting the wrong side and it would show up in whacky trims and a poorly running motor.

If I've followed everything correctly you have done a few wot pulls and are seeing leaner than normal afr, is that correct? If so then it points to unmetered air or wrongly metered air provided everything is correct with the fuel system. The maf is still used in open loop (wot) but the o2 sensors aren't.

By any chance did you put anything in the fuel that could be messing with things or changing the stoichiometric ratio of the fuel?

 

[06silverbullet]

Do you know what your fuel trims are? You can log them via the handheld or with livelink.

Why fuel trims you ask? They can point to a few things that might be happening because they correct a/f in closed loop from what's predicted to happen based on airflow.

If the trims are out of whack it means the fueling is off. If we can determine that fueling is off it helps to narrow down what's going on. An example would be excessive positive trims. This could mean that unmetered air is present and it's being compensated for with the fuel trim.

Trims should be within 6% (.06 for the log, 1.00 is 100%) in an ideal situation. If you somehow swapped the o2 sensor connections then the ecu would be correcting the wrong side and it would show up in whacky trims and a poorly running motor.

If I've followed everything correctly you have done a few wot pulls and are seeing leaner than normal afr, is that correct? If so then it points to unmetered air or wrongly metered air provided everything is correct with the fuel system. The maf is still used in open loop (wot) but the o2 sensors aren't.

By any chance did you put anything in the fuel that could be messing with things or changing the stoichiometric ratio of the fuel?

i believe my tuner talking to some other guys that use him turns off closed loop/learning.

yeah i did change the o2 sensor but that was a few months ago i assume that would cause immidiate problems no?


lito got into conact with me so i will be sending him a datalog tomorrow when i get home and see what he sees.


you are correct on the wot pulls. they seemed pretty lean from what they should be. they are in the 13.3+ range vs 12.5


i dont use any additives for fuel.

 

[BruceH]

i believe my tuner talking to some other guys that use him turns off closed loop/learning.

yeah i did change the o2 sensor but that was a few months ago i assume that would cause immidiate problems no?


lito got into conact with me so i will be sending him a datalog tomorrow when i get home and see what he sees.


you are correct on the wot pulls. they seemed pretty lean from what they should be. they are in the 13.3+ range vs 12.5


i dont use any additives for fuel.

Yes, it would of showed up right away, I was thinking you had unplugged the o2 sensors during the downtime for some reason. It's real easy to accidently swap them when hooking them back up.

He probably turned off adaptive learning but is still using closed loop. Sometimes people repeat things that they have heard and they aren't exactly what's going on. Logging long term fuel trims would be an easy way to check. If ltft stay at 1.00 then adaptive is off. It will still run in closed loop with adaptive off. Turning adaptive off keeps the ecu from learning bad habits. It's not usually done unless something in the motor setup is non standard and responsible for giving flaky readings. As long as there are short term fuel trims then it's in closed loop.

A big jump in afr to the lean side without changing anything would point to the maf or unmetered air. You cleaned the maf though. By any chance did you recently reoil the air filter if it's an oiled type? I ask because excess oil can contaminate the maf. A contaminated maf won't pick up all the air that's moving which will result in the ecu supplying fuel for less air than is being consumed.

Hope you get it figured out.

 

[06silverbullet]

Yes, it would of showed up right away, I was thinking you had unplugged the o2 sensors during the downtime for some reason. It's real easy to accidently swap them when hooking them back up.

He probably turned off adaptive learning but is still using closed loop. Sometimes people repeat things that they have heard and they aren't exactly what's going on. Logging long term fuel trims would be an easy way to check. If ltft stay at 1.00 then adaptive is off. It will still run in closed loop with adaptive off. Turning adaptive off keeps the ecu from learning bad habits. It's not usually done unless something in the motor setup is non standard and responsible for giving flaky readings. As long as there are short term fuel trims then it's in closed loop.

A big jump in afr to the lean side without changing anything would point to the maf or unmetered air. You cleaned the maf though. By any chance did you recently reoil the air filter if it's an oiled type? I ask because excess oil can contaminate the maf. A contaminated maf won't pick up all the air that's moving which will result in the ecu supplying fuel for less air than is being consumed.

Hope you get it figured out.

yeah didnt touch the sensors this time.

ok will look into that when datalogging a lot of good info thanks

ok well thats a good start to look at. i did clean the maf with maf cleaner i could spritz it again.

and no i use a dry filter

 

[TexasBlownV8]

Well, you were having a lean issue awhile back due to electrical issues. I wonder of those reared their head again.

 

[06silverbullet]

Well, you were having a lean issue awhile back due to electrical issues. I wonder of those reared their head again.

no i checked the bec and no fried wire harness/melting/burned anything. i took it all apart pulled all the fuses and relays, wire harness that feed in/out of it.

 

[TexasBlownV8]

Might need to check the voltage at the fpdm's for the over-12v from the BAP output. Although that's probably not the issue since we wired it up right, it was an issue before. Sometimes things rear their ugly heads again. This would only be suspect if fuel pressure was dropping too low.

[EDIT: OOPS!!! WRONG MEMBER!!! Thought you were someone else! DOH! ..never mind!]

 

[06silverbullet]

Might need to check the voltage at the fpdm's for the over-12v from the BAP output. Although that's probably not the issue since we wired it up right, it was an issue before. Sometimes things rear their ugly heads again. This would only be suspect if fuel pressure was dropping too low.

i dont have a bap, and i just replaced the fpdm about a year ago.

 

[06silverbullet]

think i found the issue coil or plug on #8 cylinder must be bad.

gonna move the coil to a different spot and see what happens.

 

[702GT]

think i found the issue coil or plug on #8 cylinder must be bad.

gonna move the coil to a different spot and see what happens.

Gotta love it when the car is talking to ya, just need the right tools to listen.

 

[06silverbullet]

yeah should have done it from the get go didnt even think about it. lol total brain fartism

well fuck me sideways. i swapped the coil with the number 1 cylinder. to tell whether it was the plug or coil. still missed. changed the sparkplug with a spare one i had lying around. still not registering on the datalog. i assume i';m now gonna be fishing in the harness?

 

[TexasBlownV8]

You probably have a cut in the harness. The red wire on the COP plug should have 12v with key on; the other pin goes to the PCM and may be cut or broken. You make have to unplug the large pcm plug and check continuity to the #8 cop circuit (disconnect battery first).
You've narrowed it down nicely

 

[06silverbullet]

You probably have a cut in the harness. The red wire on the COP plug should have 12v with key on; the other pin goes to the PCM and may be cut or broken. You make have to unplug the large pcm plug and check continuity to the #8 cop circuit (disconnect battery first).
You've narrowed it down nicely

just checked that the wire has 11.83 keyed on and that matches cyl 1

so which big ass connector do i need to pull from the bec to test that or does it pug straight into the pcm

so i'm slowly working on checking the trigger wire i assume is not working as it has power.

it's the white with a red marker. i'm fallowing the harness and i assume that the trigger wires split off into a squareish connector? just before the pcm between the pcm and the engine essentially

 

[06silverbullet]

is this where i should be checking for contunuity or is it going to be the actual plug in the ecu. if at the ecu does anyone have a pin layout for that ?