Tfrasca
Active member
- Joined
- Apr 20, 2015
- Location
- Ben Lomond, CA
So, I've had this Aeromotive FPR on my 142 since I did the engine swap. It's about 6 months old, I'd say.
It never help line pressure after the pumps primed, and the needle on the gauge always fluctuated up to 7-8 psi. I was getting my TLAO chips dialed in with my light blue (390cc?) injectors, but I couldn't escape a nasty lean condition under boost toward 5k rpm. Increased fuel pressure to 58 psi, and the FPR would BARELY get there. It should be capable of 30-70psi base pressure, so I took it apart to see what was up.
Sure enough, the hole that the ball valve should seal against was worn unevenly. They apparently just drill a hole, after the base is already anodized, and don't put a radius or chamfer on it. I used a counter sink bit and milled a chamfer on the seat by hand, carefully.
It seals much better now. Still leaks residual pressure after 10-15 seconds, but holds running pressure rock steady on the gauge. I've adjusted FP back down to 43 psi and am actually a bit rich at 12 psi with a 19t.
TL;DR - Be careful with these Aeromotive FPRs. Had I not installed a wideband when I did, I probably would have lost a piston...
It never help line pressure after the pumps primed, and the needle on the gauge always fluctuated up to 7-8 psi. I was getting my TLAO chips dialed in with my light blue (390cc?) injectors, but I couldn't escape a nasty lean condition under boost toward 5k rpm. Increased fuel pressure to 58 psi, and the FPR would BARELY get there. It should be capable of 30-70psi base pressure, so I took it apart to see what was up.
Sure enough, the hole that the ball valve should seal against was worn unevenly. They apparently just drill a hole, after the base is already anodized, and don't put a radius or chamfer on it. I used a counter sink bit and milled a chamfer on the seat by hand, carefully.
It seals much better now. Still leaks residual pressure after 10-15 seconds, but holds running pressure rock steady on the gauge. I've adjusted FP back down to 43 psi and am actually a bit rich at 12 psi with a 19t.
TL;DR - Be careful with these Aeromotive FPRs. Had I not installed a wideband when I did, I probably would have lost a piston...
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