Re: Help!!
 

Different battery? Maybe internal plates? I'm just guessing here

Re: Help!!
 

Ed, Are you seeing any abrupt changes in your injector Pulse width or timing? If you can see it on the Datalogger lookat the Pulse width closely it should not change, if it does we;d need to see if it's due to some incorrect input. Wish I were more familiar with the FAST system, however diagnosis should follow the same approach. Please let me know if you see anything irregular as far as the PW or timing. Joe Forgot to ask what inputs are you using for Crk and Cam? Possible Crk sensor issue, as I believe Cam is only used at start up

Re: Help!!
 

2 new 16 volt AGM batteries last week. Had 2 12s & alternator before that. No change.

Re: Help!!
 

Joe, the pulse does narrow, but I'm not sure if it's the cause or effect from the RPM drop. Usually happens about 4900, drops to anywhere from 3900 to 3200, then right back up. Has an MSD crank trigger, no cam sensor. Replaced the crank trigger, MSD 7AL2Plus box, batteries, trans brake solenoid, micro switch on the Biondo Terminator, and the FAST XFI ECU, and TPS. I tugged on, wiggled, & flexed the wiring & battery cables. Only things I can think of are the ignition coil and battery cut-off. I have thumped on the cut-off and tugged on the cables, all while the engine was running. Couldn't make it miss. The TPS graph had gotten a bit eratic, new fixed that but had no effect on the running. I'm about ready to burn it. LOL

Today I replaced the ignition switch and wiring to the ECU and MSD box.

Re: Help!!
 

Run a loop across the master cut off for one runuse BIG wire or just hook it to one pole. I had one of those give me fits on a S/C car.

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Adger, I put both cables on the same post yesterday. Probably won't get to test until Friday, unless somebody rents the track this week, and I can split the cost with them. Going tonput my old ignition coil back on it too. Running out of ideas.
Thanks.

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Ed you have a PM

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Got it! Thanks!!

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So the engine doesn't actually shut off it just loses power? You mentioned I think it sounds as if it's misfiring correct? I'd doubt you're losing voltage as I'd expect a severe "buck, backfire" as power were restored, I've seen this many times at work with intermitent power issues to various modules the veh. would act as though you cycled the ign.Did you mention you have a scope? If so this may help in diag. this issue, hopefully it has a "glitch" feature? The new crk. sensor is it the shielded type.... grounded to the block. I've seen many issues fixed mostly on the MSD digital units by installing the shielded type crk. sensor.

Re: Help!!
 

Joe it sounds like the key was shut off and back on really quick. No backfire, pop, blubber, dropped cylinder, etc. Just cleanly off & on. The air/fuel shows 12.3-1 to 12.5-1 around there, which is where it has always had it's best 60' times. Has been cutting off about 4600 to 4900, and has always been back on before it drops to 3200. Hope to get to test again this week. Points race at Ennis next week. Need to find it. Also, if it blows the tires off it never does it.

No matter how embarrassing it might be, I'm going to post the results. Might help somebody else if it happens to them.