Al Hounos

Got the rest of my exhaust finished last week. Magnaflow muffler sounds great, low and mellow. Drove the car to the welder's and barely made it. I'm getting a terrible problem with tach spikes. I'm redoing all spark related connections- CAS and spark outputs. Changing from crimps to crimps w/solder. I'm afraid it's some type of interference though. The spikes are totally random. Barely made it to the shop, but driving back home it ran perfectly 5+ miles, until about 500yds from my house, when it started bucking.

Also I've messed up my temp gauge. I removed the OEM injector harness, and cut the wires coming from it that go to the coolant sensor. I rewired them, and got it working on the MS again, but the dash gauge doesn't work. I have it wired one side to ground, and the MS coolant wire to the signal side with two splices coming off it, one to the stock ECU for fan and one to the temp gauge. This is how I understood it is wired from looking at wiring diagrams, I don't understand why it isn't working.

Oh well, I'll figure them out soon enough, but if you guys could help me out it would be great.

kingofl337

If the MS isn't getting a good connection for the temp sensor that could cause the bucking you were getting has it will rapidly swap between VE bins.

If you are running only the MS you should probably just power the CAS directly with the MS and that will assure you get a good clean signal.

Run your fan on output 4.

I'll have to look at the wiring for the temp gauge I'll get back to you on that.

Al Hounos

Power the CAS from the MS eh? Interesting.

I know it is tach spikes causing the bucking, I have datalogged it.

Al Hounos

http://msefi.com/viewtopic.php?t=19730

Al Hounos

Unfortunately the problem is still the same with the CAS powered off the MS.

New datalog in my thread, which nobody has responded to. :( Such is the big negative of an open source boy-wonder EMS.

Arkmage

iTrader: (3)

you might consider pulling the MS out and checking any components related to tach for cracked solder or loose connections... this sounds like an intermitent circuit problem. Make sure you use a magnifying glass and check BOTH side of any soldered connection. If there is a little line around it that just looks like flux, it is probably a crack... and the root cause of this problem. I've seen this before on production ECUs... needless to say the quality team was not all too happy about that.