A Sharp
Proven Member
- 158
- 13
- Nov 18, 2013
-
Platteville,
Wisconsin
I recently got a set of cleaned/flowtested FIC 1120cc's from a reputable freelancer on this site. They replaced my PTE 1000cc's, which were un-cleanable (more than 15% flow variance AFTER cleaning). However, ever since I've made the switch, I haven't been able to get hot starts to where they should be. If the car is turned off for 3+ minutes when hot, it refuses to start without some throttle. Without throttle it surges once, sputters at 300-500 rpms, then dies. Cold starts are fine. Hot starts immediately after shutoff are fine.
Another odd observation: the car runs lean for a few minutes after hot starts. It is currently set to run in open loop below 2000 rpm (helps driveability immensely with these cams). AFRs should be 14.0:1. They start at 16:1 and slowly drop down to 14:1.
Running E85. Base fuel pressure is 45 PSI. AFPR is able to hold pressure after shutdown. Not running an FPS.
Sounds like vapor lock, right? Not so sure. If I let the fuel pump run until the fuel rail is cool before attempting to start, the engine still dies. There is no pressure building in the gas tank. Furthermore, why didn't this happen with my old injectors? I can't believe that I wouldn't have noticed it until now.
I've spent hours playing with this. Here is what I've tried so far:
-Performed a BLT. Checked all vacuum accessories for leaks with a vacuum pump.
-Increased/decreased cranking fuel
-Increased/decreased idle timing
-Increased FastIdleMTISCPosition
-Enabled/disable idle air clamp
-Enabled/disabled closed loop below 2000 RPM.
-Reduced valve overlap by 4 or 5 crank degrees.
-Hotter plug/tighter gap (BR7ES, .02").
-Enabled/disabled hot start enrichment checkbox.
I've attached a log of a troublesome start. Thanks.
Another odd observation: the car runs lean for a few minutes after hot starts. It is currently set to run in open loop below 2000 rpm (helps driveability immensely with these cams). AFRs should be 14.0:1. They start at 16:1 and slowly drop down to 14:1.
Running E85. Base fuel pressure is 45 PSI. AFPR is able to hold pressure after shutdown. Not running an FPS.
Sounds like vapor lock, right? Not so sure. If I let the fuel pump run until the fuel rail is cool before attempting to start, the engine still dies. There is no pressure building in the gas tank. Furthermore, why didn't this happen with my old injectors? I can't believe that I wouldn't have noticed it until now.
I've spent hours playing with this. Here is what I've tried so far:
-Performed a BLT. Checked all vacuum accessories for leaks with a vacuum pump.
-Increased/decreased cranking fuel
-Increased/decreased idle timing
-Increased FastIdleMTISCPosition
-Enabled/disable idle air clamp
-Enabled/disabled closed loop below 2000 RPM.
-Reduced valve overlap by 4 or 5 crank degrees.
-Hotter plug/tighter gap (BR7ES, .02").
-Enabled/disabled hot start enrichment checkbox.
I've attached a log of a troublesome start. Thanks.
Last edited:
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