sputtering, no idle... help!

[420a-t]

today i started up my car to go to school and went inside. i came back out ten munutes later and my car was off. i tried to turn it on and it just started for a second then died. i tried again with my foot on the gas pedal, gave it some gas and it started....but once i take my foot off the gas, it dies. so i sat there for about five minutes giving it gas and after i did that it idles, but not good at all, like 450 rpm. feels like its way rich. could it be in "safe" mode? im so confused...

all of my vacuume lines are connected, plug wires, fcd is still intcat etc. i scanned it with the strap-on...oops...snap-on scan tool and everything looks good to me:

main o2 (mv): goes from .49 to .87
exhaust status: lean to rich very quickly
fuel(%): -3 to -7
map(kPa): 51
coolant (degrees celsius): 72
map (Volts): .70

i dont know what it could be. after i scanned it i had to drive it home so i decided to get on it (boosted at 5psi) and it stumbles really bad in the upper rpm range (pulling back timing? knocking? fuel cut?) the night before everything was going great. i have no clue. any help would be greatly appericiated.

 

[Blitzeclips]

Have you noticed any problems leading up to this? Any other stuttering, etc.? Were you driving hard on the car the night before? How many pounds of boost have you usually been running?

If you're boosting 15-16 psi on a regular basis, I would think your timing advanced under boost. Maybe causing it to misfure now..

Did you feul pump prime? Any voltage to it? If a car doesn't start it can usually lead to feul, spark or air. You need to check that pump, because if it's not priming then you're not getting feul..

Check your plugs also. They'll tell you what is going on. When was the last time you changed your plugs?

Reason I ask is I had a similar problem. My car would BUCK HARD @ boost or when I would engine break my stops. I checked the plugs and they were all types of nasty. Turns out then hadn't been changed in 2-3 years. Even after my motor swap! nono
I changed the plugs and also checked my MAP sensor. It was also looking bad. There was gunk built up on it, and within the housing on the plenums far left. I cleaned it out and everything has been fine. (knocks on wood). I figure if the sensor was getting clogged when I was driving, then ECU wouldn't read manifold pressure when I built boost. So ultimately it seemed like I was flooding the engine/running rich...

My car was also doing that when I was taking test runs tuning my boost controller. I would get boost spike very badley even after setting the BC to 2-3 psi. TUrns out my vacuum lines were pinching. They were hi-perf. silicone ones too. The heat my hood weakened their structure and the walls were collapsing(pinched) once hi pressure would build. I fixed this by simply replacing these lines with feul hose. You WILL NOT pinch that stuff...

GOod luck though. Let us know what you see on the plugs and MAP sensor... Check your pump voltage for 12V and make sure you hear it prime. Also look for de-formation in the shape of your vacuum lines...

 

[matt98eclipse]

check your spark plug wire and your spark plugs i had a similar problem when i was getting into higher boost around 7 or 8 pounds my car would start bucking and miss firing so i changed my wire and plugs and gaped them to 30 everything ran great after that!!

 

[420a-t]

alright ill check my plugs tommorow. what spark plugs would fit that are steps colder than stock? and yeah i checked my fuel pump. when i scanned my car it said that it was on and i heard it wine like a mini siren. and it did prime also.

to blitzeclipse, no i have not had any problems before this morning. i mean the usual timing gets pulled out when the car is warmed up and i have been on it all night. i checked my map and the fcd (but didnt pull the map out yet) and everything seems ok. all the wires are nice and tight.

what would cause it to all of the sudden not want to idle though? i didnt think my spark plugs could do that. mabye the map? ill check that...

also, i dont know if this means anything, but i tried WOT again today and it wont go past 4k rpm. could the fcd be doing that? i hope this all makes sense...

 

[4UH8ERS]

alright ill check my plugs tommorow. what spark plugs would fit that are steps colder than stock? ...

NGK-BRP7E

what would cause it to all of the sudden not want to idle though? i didnt think my spark plugs could do that. mabye the map? ill check that......

MAP
IAC
TPS
timing

also, i dont know if this means anything, but i tried WOT again today and it wont go past 4k rpm. could the fcd be doing that? i hope this all makes sense...

thats a map sensor problem. heres your fix.

1. do this disconnect your positive battery trerminal
2. take out your map sensor and clean it make sure all connections are good if running an fcd.
3.re-install the MAP sensor
4. re-connect your battery.
5. rev it up!!!!! tell me what happens i have seen this problem before.

 

[dr1665]

NM. pm sent

 

[420a-t]

ok so i went out and checked my map and everything is ok there so is the fcd. i also checked my wires plugs and made sure they were gapped correctly. nothing is abnormal that i can see. coil is fine. also, i went to autozone to get some plugs and the guy there thought he knew everything about my car. he said that the bosch platinum (stockers) would be just the same as a copper top. no, right? as i was there i decided to scan it. i got a running too rich code. what would make my car all of the sudden run too rich? im really not feeling like taking it to someone else to have it, excuse me, her, worked on

 

[06jds3772]

This might sound a bit out there..but it happened to me...if you run an auto trans MAKE SURE the wire (orange/black) between the TCM and ECU does not have any break in it at all...this happened to me...I checked everything out for at least a week...then I noticed the wire had snapped somehow so I put it back together...car ran fine...pulled it apart again...started having problems again...did this several times to confirm thats what it was...and it was......so yeah..if you're AT check that wire

 

[4UH8ERS]

i got a running too rich code. what would make my car all of the sudden run too rich?

O2 sensor.



As for the redlining at 4k though. I don't know of anything other than the MAP that would cause it. you say you checked it and all was fine? wisemen enlighten us please.