I posted a thread last April & got some great advice - but it hasn't resolved my problems...yet.
Here's my set-up & issues that I'm hoping some of you world class mechanics can diagnose:
84 GN with recent rebuild on all motor internals
10/10 stock crank
.030 cylinder bore with hypereutectic pistons
Poston's GN107T cam
green stripe 30# injectors
Kirban's billet adjustable f/p reg
160 degree t-stat
Walbro 340 w/hotwire kit
The car was starting, idling, & running great through the gears but at constant RPM would start to buck then backfire hard through the throttle body & blow black smoke out the exhaust. This was with TS42's & stock regulator (& it was gas fouling the plugs at ~150 mile intervals.
I had AC TS42's in it with stock regulator. I've sort of concluded that it was running way fat with the cam, inj, cold plugs, & stock reg, so went to TS43's & adjusted the f/p down (a mechanic installed the adj reg & plugs & at this point I don't know for sure what PSI is on the rail). He also found that the boost line to the wastegate sensor was blowing off causing overboost.
In the process, the ignition quit firing on 1, 3, &5. ECM & crank sensor were swapped with '84 parts, coil pack & module was swapped with 'known good' C3I setup from 87 but the 'mechanic' that installed it didn't know there are differences in the pin assignments. According to him, no changes with any of the ignition changes.
I'm at a loss here - - yup, confused. Any ideas??
Here's my set-up & issues that I'm hoping some of you world class mechanics can diagnose:
84 GN with recent rebuild on all motor internals
10/10 stock crank
.030 cylinder bore with hypereutectic pistons
Poston's GN107T cam
green stripe 30# injectors
Kirban's billet adjustable f/p reg
160 degree t-stat
Walbro 340 w/hotwire kit
The car was starting, idling, & running great through the gears but at constant RPM would start to buck then backfire hard through the throttle body & blow black smoke out the exhaust. This was with TS42's & stock regulator (& it was gas fouling the plugs at ~150 mile intervals.
I had AC TS42's in it with stock regulator. I've sort of concluded that it was running way fat with the cam, inj, cold plugs, & stock reg, so went to TS43's & adjusted the f/p down (a mechanic installed the adj reg & plugs & at this point I don't know for sure what PSI is on the rail). He also found that the boost line to the wastegate sensor was blowing off causing overboost.
In the process, the ignition quit firing on 1, 3, &5. ECM & crank sensor were swapped with '84 parts, coil pack & module was swapped with 'known good' C3I setup from 87 but the 'mechanic' that installed it didn't know there are differences in the pin assignments. According to him, no changes with any of the ignition changes.
I'm at a loss here - - yup, confused. Any ideas??