moldyviolinist

cross post to general rotary tech help:

hi guys, got a problem with my fd.

bought an fd last year and it's been running flawlessly, tons of power, etc.
stock twins modded to parallel, power FC, hks twin power, high flow cat, bigger smic. boosts to around 15 psi.

driving on the highway (5th gear, 70mph, light throttle) on saturday it suddenly started shaking and shuddering, and i had barely any power. I noticed AFRs went rich - around 12, usually it runs about 14 on the highway. EGT was around 1300-1400 F, water temp around 170. Oil pressure looked normal, boost was kinda jumping around at 0. I pull off, and the car dies after I push the clutch. Couldn't start it again, cranking sounded weird.

I'm a noob and have no tools, so I towed it to a general mechanic, as I figured it was something simple.

They haven't been able to find the problem: so far, we know we have fuel pressure, we know we have spark and we changed the spark plugs. Catalytic converter is flowing fine. They were able to start it when it had cooled off, and it'll run with barely any power until it warms up a bit, then it'll die again.

mechanic performed a compression test with a regular compression tester (not rotary) and got 60-70 psi on every face, so he believes its low compression and is "flooding out". but there's no way every apex seal failed at the same time, and it definitely didn't have low compression last week (tons of power, no problems with hot start). Since the compression test is reading approx the same for each face, I figure the seals are fine. If i blew a seal, presumably one face would read lower psi right?

So, any ideas? current plan is to go get a proper compression test at the stealership, but would rather not shell out another 250 bux. also if anyone is local and wants to help me out, i can certainly provide beers and food

86gxl_fc

the compression test they performed, did they do it on a fully charged battery?
Just curious/narrow down possible reasons.

moldyviolinist

Thanks, yes I suspect they did not. They finally checked the ignition coils while hot, and one coil wasn't sending any spark when it was warmed up. Going to replace that, hopefully that'll fix the issue.

MaximaPower

did replacing the ignition coil fix the issue?
I'm currently having this similar issue as well. Car bogs down while driving then wants to stall out

moldyviolinist

didn't fix it yet. currently in the process of moving, but i want to replace the spark plugs once more, i suspect they may be fouled. But currently still shutting down under load.

cewrx7r1

iTrader: (2)

Check the map sensor and its wiring.
Rich AFRs mean too much fuel.
No spark = no burning of fuel = no O2 used = lean