intermittant issue....sd2....caught a log finally,please help

[greeneyegi]

ive had this problem every once in a while.
it only happens when i start the car,never after its been started and running.it doesnt matter if its cold or hot.finally i caught it and i got a log.
i will start the car and it runs like its completely flooded,smokes,and sounds like its running on 3 cylinders.some times i can restart and it goes away.sometimes like this morning it wouldnt go away.i started cold this morning and it happened.i restarted a couple times and its still doing it.so i got out the laptop and got a log.its got a code 34 of a mass air flow reading low
and 24 vss signal reading low.
i took the iac off and it still idled and ran on the second log.
the third is a good running car the last time it ran.....any ideas will help thanks guys
pxl wideband

 

[greeneyegi]

IM TRYING TO reset everything back to original settings,and i cant change any of the settings?

 

[Pronto]

Haywire 4130 has the same issue going on with his SD2. You might PM him to see if he has any thoughts on it.

 

[greeneyegi]

thanks pronto!

 

[Pronto]

double post...

 

[greeneyegi]

do you know if their is a thread started?,
alot of people are out of town,im trying to make it to the tracks

 

[TurboBob]

after it runs for a bit, shut it off and see which cylinders' header pipes are coldest.

Bob

 

[greeneyegi]

its definitely flooding,i can only get it to start with the throttle floored.it runs only for a second or two,a few backfires through the exhaust and intake.if i just start with no throttle it fires then dies.
but the coldest is cylinders 6,1,3 thats with my hand.but thats very close,they are all real close.none are cold.
i do have a tr6 also,bob

 

[greeneyegi]

my injector dc is 7% @ 600rpm,?on a normal idle its 1.5%
mass air reading too low?this is sd chip
this is the first time its done it this long,which to me is a good thing cause maybe illl find out what it is.
i put two logs running crappy and a log from a couple days ago that was great...the one with the date is the good one.

 

[greeneyegi]

just went out and its back to normal.

 

[greeneyegi]

went for a drive and logged the run....everything was good then it had a hickup?never before has this happened.
im attaching the log.it seems to me the computer died for a sec?the fpressure,wideband,boost,iac,maf,ve all still worked.seems like the ecm just stopped.
read,or logged .
frame #10267 is right before it happened.

 

[TurboBob]

the glitch was an ECM reset. I'm not sure if its related to the other issue though.

looking at the file "second bad...." after starting it the MAP only went down to 80ish, so you were getting lots of fuel from that most likely.

I would investigate the MAP wiring and hoses, etc.

Bob

 

[haywire4130]

This is exactly what my car has been doing intermittently, I parked it since I don't really trust it to go anywhere. I only had it happen once right after startup, the other times it has been just normal driving. I haven't had 5 minutes to look at it but I'm 99% sure it's either a bad pl to ecm connection or a problem with the Pl itself.
Another thing is it seems to have lost its tune? Last year I had it pretty dialed in, this year my cf has been all over the place and it doesn't run as strong. My garage isn't insulated so the car sees big temp swings (sometimes I get a little fog in my gauges) so I'm leaning toward a poor connection at the ecm.

 

[haywire4130]

The strange part is after a few wot restart attempts to clear the flood it will usually clear out and run perfect (without changing or messing with anything). It's frustrating for sure, and unlike you I wasn't able to catch it on a log so it's just guesses. I did get the same mass air code which I found odd since there isn't one hahaha. No vss code though. I'm gonna try to get after it early this week, hopefully we can help each other sort them out, I'll keep an eye on this thread

 

[TurboBob]

the SD2 chips use the MAF codes as MAP codes.

Eric and I were discussing changing that in the newer version (the e85 flexfuel update), but I'm not sure if he did.

Bob

 

[greeneyegi]

this happening before i did the gauge swap,but anyways....after switching my 145mph analog dash out with a new never installed avc dash,with an electric speedo.when i first turned the car on my alky started pumping alky.
it turned out i lost the ground to the MAP.?????????????dont know how that happened.i plugged in my powerlogger and disconnected the pump,and saw 30# boost reading on map,during a non running situation.thats what made me check the wires.i found the ground wire on the map was not grounded anymore.so i dont know how it would have read 5v without ground.
their is 3 wires.5v/G/Signal....so i grounded the wire on the map.finally it went normal.

the glitch was an ECM reset. I'm not sure if its related to the other issue though.

looking at the file "second bad...." after starting it the MAP only went down to 80ish, so you were getting lots of fuel from that most likely.

I would investigate the MAP wiring and hoses, etc.

Bob

so what does an ecm restart mean?
what do you recomend i test on the map?

 

[greeneyegi]

im thinking theoretically here,i have a vacuum/pressure hand pump.the next time this happens,if i run the logger and use the pump to create 45 on the map then theoretically it should run?

 

[TurboBob]

theoretically..... I have never tried that.

the MAP sensor is the PRIMARY contributor to the fueling algorithm. Flaky grounds, flaky sensors, etc will have dramatic effects on the fuel delivery.

spend extra time making sure that the 5v and ground feeds to the sensor are 100% reliable. TPS 5v and ground are the best way to go, body grounds and the stock analog gauge module will cause problems.

Bob

 

[greeneyegi]

everything in my world is theoretical,keeps me out of trouble when explaining situations/problems at work,im a controls tech.
im looking at my logs,the tune pages have these weird colors/yellows and tans?any ideas?

theoretically..... I have never tried that.

the MAP sensor is the PRIMARY contributor to the fueling algorithm. Flaky grounds, flaky sensors, etc will have dramatic effects on the fuel delivery.

spend extra time making sure that the 5v and ground feeds to the sensor are 100% reliable. TPS 5v and ground are the best way to go, body grounds and the stock analog gauge module will cause problems.

Bob

yes i use the 5v from the tps,long time ago the 5v from dash wasnt right on enough and my boost reading wasnt within 4#,that solved the issue when logging.

 

[TurboBob]

how is the sensor grounded?

the logs with the funny tune settings didn't save correctly,

try using the latest PLC I posted in the flex fuel thread. It has a couple fixes in it for that.

Bob