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Hi folks,
I've brought my Aero back to life after about 4 years sitting thanks to a blown head gasket and rust on the rear shock towers. New head gasket is in and welder lined up to take care of the rust shortly.
Been sorting and fettling as I drive it around and get used to it again, and there are a few issues...
1) when i start it cold in the morning, it idles dead smooth, then as i pull out, it stutters and misfires with throttle applied. the first few hundred yards is tough until it has a bit of heat in it. it bucks and i can hear the misfiring... actually, the car has always done this since I bought it, even before the HG blew.
2) once it's warm, it randomly misfires at any RPM, including idle. I don't remember this from before.
3) boost isn't anywhere near what it was before the HG blew. compression is 150PSI on all four, hot or cold, which sounds right given the 1993's lower 8.5:1 C/R, compared to '94-'98 at 9.25:1
I am running exclusively 94 octane Chevron fuel. Fuel filter is a brand new Mann. Spark plugs are brand new NGK BCPR7ES gapped to 0.9mm. Was getting O2 sensor codes, so swapped that out for a brand new Bosch unit specced for an '88 Mustang 5.0, and used nice 3M butt splices and heat shrink wrap to switch to the Saab wiring. Passed emissions with flying colours after that.
I've tried a known good black DI from my friend's 9-5, which doesn't cure any of the aforementioned. I have cleaned the heck out of my BPC, and it passes the normal tests.
If I drive around with the BPC plug disconnected, then plug it in, I get boost slightly into the red for the first few runs and not a trace of knock. It used to go and sit half way into the red and occasionally hit the fuel cut out before the HG blew. But after a few runs, it's back to sitting mid red/yellow section - i.e. a bit above basic boost.
I am trying to line up access to a Tech II or ISAT to do an ETS calibration. Speaking of ETS, I just installed a brand new TCS safety valve and red/white one-way valve, as I was having intermittent LHM issues right before the HG blew due to the safety valve and had swapped it out for the cruise valve to get by.
If I disconnect the wastegate hose from the BPC, I get wild silly boost up to the fuel cut with zero audible knock.
Spark plugs read perfectly with about 750km on them so far.
I do know a gentleman with a '93 CSET with known good red DI and BPC, guess I could bug him and swap those...
Not sure why but I kind of suspect my ECU... the aforementioned '93 CSET is an automatic, but could I steal that ECU to try in mine to see if it behaves?
Thanks for any thoughts!
--Jeff
'93 Aero - 209,000km
'85 SPG - 242,000km
posted by 70.79.19...
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