I have a miss that I'm unable to trace and appreciate input and comments.
Van Diemen RF01
Pinto
Professionally built engine has approximately 4 competition hours - 3 weekends
Chassis underwent ground up winter 2013
Wiring all renewed/verified correct
Engine new for 2014 season.
Points/condenser ignition. (Please no debate around Pertronix vs points - I've used points for over 20 years with no issues)
Mechanical fuel pump
Good news is that this miss is reproducible in the shop. Bad news is that I've run out of things to try.
Miss is generally a high speed miss, starting around 5000 RPM, getting progressively worse as the upper ranges are reached. At 6500-7000 it has a "ba-da-ba-da-ba-da-ba" that almost sounds like a rev limiter. I don't have a rev limiter.
What I've done with absolutely no effect:
New points/condenser
Exchanged distributor
New Coil
New distributor cap, rotor, coil & spark plug wires
New Plugs
New Master switch
New Ignition switch
Bypassed all onboard ignition/starter wiring & replaced with mini harness made up for test purposes
Replaced Battery
Verified carb is correct - it went back to the engine builder who ran it on an engine on his dyno. Not the carb
Exchanged carb
Replaced fuel pump
Verified valve lash
Bypassed the Mychron dash - left it completely out of the system
Ran it on the onboard battery & the jumper battery separately
Replaced starter (really getting obscure here - possibly the big lug on the solenoid was arcing internally - it wasn't)
Replaced fuel lines
Verified the fuel level is correct in carb after hot cut.
Verified the fuel vent is working properly.
Fuel filter shows no signs of deterioration of cell foam
History of the miss:
-Weekend #1 - no problem
-Weekend #2 - Double weekend - No problem Saturday, started in Sunday's race.
-Miss was reproducible in the shop so between events, I tried a lot of things listed above and convinced myself it was the carb. Replaced the carb with another, and went racing.
-Miss was present through practice and qualifying on Saturday of the next event. Saturday evening, we replaced a fitting on the "hot" wire to the ignition, separated the plug wires a bit better near the distributor cap and replaced the plugs. Miss WENT AWAY for the morning race and came back during the afternoon's race.
-Shop running (2 weekends worth!) since to try to figure this out.
Any and all thoughts welcome. I'll even be open to the Pertronix suggestion if someone wants to lend me a distributor that's already set up. I'll pay freight both ways to/from 33907.
Thanks
John
Van Diemen RF01
Pinto
Professionally built engine has approximately 4 competition hours - 3 weekends
Chassis underwent ground up winter 2013
Wiring all renewed/verified correct
Engine new for 2014 season.
Points/condenser ignition. (Please no debate around Pertronix vs points - I've used points for over 20 years with no issues)
Mechanical fuel pump
Good news is that this miss is reproducible in the shop. Bad news is that I've run out of things to try.
Miss is generally a high speed miss, starting around 5000 RPM, getting progressively worse as the upper ranges are reached. At 6500-7000 it has a "ba-da-ba-da-ba-da-ba" that almost sounds like a rev limiter. I don't have a rev limiter.
What I've done with absolutely no effect:
New points/condenser
Exchanged distributor
New Coil
New distributor cap, rotor, coil & spark plug wires
New Plugs
New Master switch
New Ignition switch
Bypassed all onboard ignition/starter wiring & replaced with mini harness made up for test purposes
Replaced Battery
Verified carb is correct - it went back to the engine builder who ran it on an engine on his dyno. Not the carb
Exchanged carb
Replaced fuel pump
Verified valve lash
Bypassed the Mychron dash - left it completely out of the system
Ran it on the onboard battery & the jumper battery separately
Replaced starter (really getting obscure here - possibly the big lug on the solenoid was arcing internally - it wasn't)
Replaced fuel lines
Verified the fuel level is correct in carb after hot cut.
Verified the fuel vent is working properly.
Fuel filter shows no signs of deterioration of cell foam
History of the miss:
-Weekend #1 - no problem
-Weekend #2 - Double weekend - No problem Saturday, started in Sunday's race.
-Miss was reproducible in the shop so between events, I tried a lot of things listed above and convinced myself it was the carb. Replaced the carb with another, and went racing.
-Miss was present through practice and qualifying on Saturday of the next event. Saturday evening, we replaced a fitting on the "hot" wire to the ignition, separated the plug wires a bit better near the distributor cap and replaced the plugs. Miss WENT AWAY for the morning race and came back during the afternoon's race.
-Shop running (2 weekends worth!) since to try to figure this out.
Any and all thoughts welcome. I'll even be open to the Pertronix suggestion if someone wants to lend me a distributor that's already set up. I'll pay freight both ways to/from 33907.
Thanks
John
Aucun commentaire:
Enregistrer un commentaire