TPS Switch Wiring
10-14-2013, 07:03 PM
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TPS Switch Wiring
Could faulty TPS wiring impact turbo spool?
I finally uncovered a gremlin that had been causing issues for years. My TPS connector was bad. The symptoms were: intermittent pulsing idle on startup (1 in 25 starts), a single misfire at idle (after 10 minutes at idle), engine sometimes ran rough between 2k and 3k rpms (1 in 50 trips). During one of the pulses at idle, I put my thumb on the TPS connector and it immediately stopped. When I removed my thumb, it came back. I purchased a LR kit for the connector and had it replaced at a shop. All of the symptoms listed above are now gone. However, boost appears to coming on more quickly and the KLR is clicking away in the low rpm range.
Could my car now be running lean because the boost is now coming on earlier?
I have a 1986 944 Turbo with a rebuilt 2.5L, LR MAF, Mafterburner, Garrett GT30R (3076R) double ball bearing turbo, 3 inch downpipe, 3 inch exhaust, 968 6 speed plus many other engine modifications. Below are some old dyno charts.
The Mustang charts were done on the same day at 15 psi and 17 psi. The DynoJet was done on a different day at 18 or 19 psi. Note: the boost on the chart is wrong. The shop notified me that their boost sensor was off. My digital gauge was showing between 18 and 19 psi.
Before I invest money in a new dyno tuning session, is my hypothesis possible that the TPS wiring was preventing the turbo from spooling early and I need to redo the fuel maps? I am assuming the KLR clicking is the unit retarding the ignition because of detonation.
Any advice appreciated. Thanks
I finally uncovered a gremlin that had been causing issues for years. My TPS connector was bad. The symptoms were: intermittent pulsing idle on startup (1 in 25 starts), a single misfire at idle (after 10 minutes at idle), engine sometimes ran rough between 2k and 3k rpms (1 in 50 trips). During one of the pulses at idle, I put my thumb on the TPS connector and it immediately stopped. When I removed my thumb, it came back. I purchased a LR kit for the connector and had it replaced at a shop. All of the symptoms listed above are now gone. However, boost appears to coming on more quickly and the KLR is clicking away in the low rpm range.
Could my car now be running lean because the boost is now coming on earlier?
I have a 1986 944 Turbo with a rebuilt 2.5L, LR MAF, Mafterburner, Garrett GT30R (3076R) double ball bearing turbo, 3 inch downpipe, 3 inch exhaust, 968 6 speed plus many other engine modifications. Below are some old dyno charts.
The Mustang charts were done on the same day at 15 psi and 17 psi. The DynoJet was done on a different day at 18 or 19 psi. Note: the boost on the chart is wrong. The shop notified me that their boost sensor was off. My digital gauge was showing between 18 and 19 psi.
Before I invest money in a new dyno tuning session, is my hypothesis possible that the TPS wiring was preventing the turbo from spooling early and I need to redo the fuel maps? I am assuming the KLR clicking is the unit retarding the ignition because of detonation.
Any advice appreciated. Thanks
