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Ignition Timing lesson learned

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  • Ignition Timing lesson learned

    So, I've had my Typhoon for a few years. When I first bought it I did the usual tune-up. Change oil, Cap, Rotor, Plugs, Wires...set timing. Recently I changed the harmonic balancer for a Fluidampr piece. I didn't think to check timing again. I have driving it off and on for a year or so since the balancer change. It seemed to run just fine. On a recent drive I was playing around and out of nowhere a pop and surging at idle. The Check Engine light would only flash when it was stumbling. It would also die out. So, I start troubleshooting (throwing parts at it). I thought it was fixed after replacing the IAC, Plug Wires, Fuel Filter, and O2 sensor. Test drive after the O2 sensor change went really well. Joyed, I was ready to make the drive to L.A. for the RADwood show at the Petersen Museum. I made it 10 miles from home and it started breaking up at all RPMs. Bummer. I nursed it back home and went anyway. Good news was there was a Syclone and 2 other Typhoons representing! Monday I was back at troubleshooting. Where to start now? I check timing. It is showing 10 degrees advanced on the balancer with the brown/black wire connected. I disconnected the brown/black wire, Now it barely was running and was totally off the marks at probably 20 Degrees retard. With a new cap and rotor and ignition module on hand I changed them out of preventative maintenance, and set timing to zero with brown/black wire disconnected. Reconnected wire, reset ECM....Hmm what do you know. Smooth running. Long test drive, no issues at all. FWIW with the brown/black wire connected the marks on the balancer show 30 degrees at idle/ So, here's what I think happened. The original balancer ring slipped over time as is common. I originally set the timing to that slipped mark. Then I replaced the balancer, and went on about my business. Perhaps the backfire did something to the module I don't know. But it appears normal now, so... Lesson Learned: Check actual TDC. DO NOT trust your OEM balancer.
    1940 Ford Coupe--completely disassembled for buildup/resto
    1973 Land Cruiser FJ40--too many mods to list, but on 37's
    1993 GMC Typhoon--#2129 Green/Grey--original ATR stuff, HoodTuned
    1996 Land Cruiser FZJ80--Factory locked, few light mods
    2000 Dodge Ram 2500 Diesel--Some mods

  • #2
    Those slipped balancers will sure mess with a person. I have had two on SyTy's. On my Ty, while doing a few things to the truck. I went ahead and checked the timing. Looked like it was way off. So I went ahead and set the timing. Well, the truck ran poorly after the adjustment. I realized then that the timing had been correct and balancer had slipped. A quality replacement harmonic balancer took care of that issue.
    Phil
    91 Syclone 2097
    92 Typhoon 0042 Black/Black
    93 Typhoon 1955 Royal Blue

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