Saab 9-5 aero misfire only at idle.

[cankersen]

Hi saab people.

I have a 9-5 aero estate 01. my problem is i get random misfire in idle only 800-1200, i get in 60 secounds, 60 misfires but i have misfires on all of them. some more then other and different witch one is the one with most misfire.
example on 60 secs record.

cylinder 1: 4 misfires.
cylinder 2: 7 misfires.
cylinder 3: 54 misfires
cylinder 4: 37 misfires

if i then wait 1 hour, deletes DTC, and the record for misfires, then it could like like this.

Cylinder 1: 12 misfires
cylinder 2: 55 misfires
cylinder 3: 30 misfires
cylinder 4: 8 misfires


When the car runs on normal drive 20-25km run. there is max 3 misfires total as long as it is above 1200 rpm


The car has new plugs, ignition cassette, turbo overhall and rebuild, chainkit, valve lifters, valves, cylinder head gasket, intlet gasket, exhaust gasket, PCV system include the one way valve, throttlebody is not that old max 15.000km done, new oil pump, pan has been cleaned.

I am wondering if the vacum hoses could be the problem?, also one of the new lifters is noisy but i dont think that should be my problem.


all kind of help is welcome, thanks you!

[cankersen]

all injectors has been tested at pro center on different kind of duty cycle,
other cassette has been tryed with out luck.

i have plugged an AFR sensor in the back of the exhaust and it says 18:1 in idle, also the plugs are totally White / gray.

[swisssaabist]

not wrong type of plugs ?

[cankersen]

not wrong type of plugs ?

Hi mate. No they are the ones WIS tells me the use, and they are new.

Thanks for asking.

Fail codes are P1300 and P1304,


Tech 2 tells me a fuel pressure on 2,5 bar in idle. im wondering if i should try to measure it manually with a barometer at the fuel rail, as WIS tells 3 bars. there is nothing to fell on hard accelrations as stumble or misfires on Tech 2.

also i am at the momment resealed all O-rings at the inletmanifold, as to the fuel regulator, and to the sensor at the firewall ?, also i have replaced the socket to the brake booster (mine is with Automatic gear) and then i replace the new gasket to the inlet manifold with a new one Again.

[southsaab]

Here's another thing to try that was helpful for me. If you are currently using spec plugs, NGK PFR6H-10, try switching to copper plugs, NGK BCPR6ES-11, or a cooler plug, BCPR7ES-11, or what I've found works great for me, BCPR7ES. The 10 and 11 refer to the pre-set gaps of 1mm and 1.1mm. The BCPR7ES has a pre-set gap of .9mm. My car, which is a 2004 ARC with 235L engine, misfired noticably occasionally under acceleration until I switched plugs. Not saying that it will work for you, but since Trionic can be very sensitive to its ignition components, it may be worth it to experiment. Tuned cars normally run cooler plugs than spec, and turbo cars in general like a somewhat smaller gap. Doesn't take as much voltage for the spark.

Anyway, just some options to try that are easy and cheaper than the alternatives.

[cankersen]

Hi. Yeaah could be a try worth. ive bought a new fuel filter also, and i am waiting for parts from local saab dealer..