T1 plug sparks in test, not in running motor...
02-01-11, 06:55 PM
#1
40k worth of fail
Thread Starter
iTrader: (5)
Join Date: Mar 2001
Location: Hermosa Beach, CA
Posts: 1,312
Likes: 0
Received 0 Likes
on
0 Posts
T1 plug sparks in test, not in running motor...
Car stats: Power FC, stock ignition, stock fuel system, non-seq, large streetport
Symptoms: Thumpier than usual idle, throwing visible gas vapor from tailpipe (incomplete burn), T1 plug is wet (not firing). T1 plug shows spark when pulled from the block & grounded (when dry). The car had rough starts for a few months leading up to this with a bouncing idle for a couple of minutes before smoothing out... didn't stall dropping to idle, though. (At the time, I figured the Power FC was just making some adjustments.)
What I've tried: Tested/confirmed continuity across T1 circuitry all the way back to Power FC, swapped Power FC for stock ECU, swapped T1 coil & igniter, grounded all plugs testing spark, swapped wires, swapped T2 coil checking spark, etc.
It just hit me as I wrote this post that this is likely a leaky/open injector on R1 that is washing out the T1 plug as the car attempts to start. The "final straw" from the rough starts that caused me to tow it home was it starting on one rotor, which likely means the leaky injector washed out both R1 plugs before the car started.
Right??
(Also something weird discovered in this process... my car runs with the fuel pump relay pulled and I cannot fathom why.)
Symptoms: Thumpier than usual idle, throwing visible gas vapor from tailpipe (incomplete burn), T1 plug is wet (not firing). T1 plug shows spark when pulled from the block & grounded (when dry). The car had rough starts for a few months leading up to this with a bouncing idle for a couple of minutes before smoothing out... didn't stall dropping to idle, though. (At the time, I figured the Power FC was just making some adjustments.)
What I've tried: Tested/confirmed continuity across T1 circuitry all the way back to Power FC, swapped Power FC for stock ECU, swapped T1 coil & igniter, grounded all plugs testing spark, swapped wires, swapped T2 coil checking spark, etc.
It just hit me as I wrote this post that this is likely a leaky/open injector on R1 that is washing out the T1 plug as the car attempts to start. The "final straw" from the rough starts that caused me to tow it home was it starting on one rotor, which likely means the leaky injector washed out both R1 plugs before the car started.
Right??
(Also something weird discovered in this process... my car runs with the fuel pump relay pulled and I cannot fathom why.)
02-04-11, 02:41 PM
#2
40k worth of fail
Thread Starter
iTrader: (5)
Join Date: Mar 2001
Location: Hermosa Beach, CA
Posts: 1,312
Likes: 0
Received 0 Likes
on
0 Posts
I'm just gonna post this here for the future reference of others since no one responded. (What happened to the people who actually knew the rotary around here??)
I took the injectors to RC Engineering and indeed, one of the primaries was "dripping" before service. Like a dummy, I didn't actually mark which ones came from the front rotor, so I'm only left to assume I was correct. Now they're all clean and flowing within 1cc of their rating.
I have a couple more maintenance things to do before I know if this was 100% the issue.
I took the injectors to RC Engineering and indeed, one of the primaries was "dripping" before service. Like a dummy, I didn't actually mark which ones came from the front rotor, so I'm only left to assume I was correct. Now they're all clean and flowing within 1cc of their rating.
I have a couple more maintenance things to do before I know if this was 100% the issue.
Thread
Thread Starter
Forum
Replies
Last Post
trickster
2nd Generation Specific (1986-1992)
25
07-01-23 04:40 PM