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rx7turbo1 03-21-2004 11:40 AM

Last night, I got my FC started after many fuel, timing and wiring issues that Alastair helped me battle out. After correcting all the issues, we still had no luck. The final touch was correcting the high fuel pressure by upsizing the return fuel line. Now that the pressure has been dialed in at 45 psi, the amount of fuel was dead on and the warmer weather helped the chemistry. I'm ****** siked!! It actually idled at 1000rpm with 3 vacuum leaks!! For some reason it liked a lot of timing advance in the lower RPMS...





Now, I am battling out this PITA problem, where the TEC unit powers off due to low voltage at approx 500rpm. This was really wierd, since that was the point where the engine was about to turn itself over.. This started to happen after many cranks with the starter, which would burn your finger at the touch. It could have been the cause of resistance, but I'm not sure...



I have a few possible reasons I came up with.. The battery was relocated a while back to the rear pass bin. The power lead is 4 gauge, thin-stranded, car audio monster cable stuff I found at a local car audio store. It goes directly from the battery to the starter, then to the fuse bus. The FP is tapped directly into the battery terminal. This leaves the TEC II unit dead last. I think there is too much resistance, b/c I know the power source is good (red optima with jumper cables from another car running). The TEC reads 8.5 volts until 500rpm where is turns off from low voltage. I'd like to rewire this entire turd job with thick 2 gauge wire directly to the fuse bus and call it a day. Then add more engine-chassis grounds. What do you guys think? The alternator is using stock wiring. Should I super-size them?



I also have to JBweld these vacuum holes in the manifold. BDC style. heh



Here are some older pics from 2001..



http://www.genxracing.com/images/My87TII/061701-8.jpg

http://www.genxracing.com/images/My87TII/

djgiantrobot 03-21-2004 12:41 PM

man! you should have called me!



anyway, i think 4 gauge is a little thin for your main leads to the battery so you are headed in the right direction there, also according to the tec manual, it doesn't like to have a fuse inline to the power supply, just straight 12V, that is a cause of increased resistance according to electromotive.



after that problem has actually been corrected (thanks for nothing eip) you might want to consider an accuvolt for powering both the tec2 and fuel pumps so you can keep them all at 14v.

rx7turbo1 03-21-2004 01:31 PM

HAHA! Hey Man! Quick reply. I'll be there today if you wanna swing by.



I'm gonna go back and fix what I can, with stuff from Clarks Hardware. That AccuVolt is EXACLTY what I was looking for. I was thinking about a lightning cap, but this looks even better! Once I find one on ebay, I'll buy it. DAAMN $399 new! The FP is rated for 13.5, so that's cool, and the TEC NEEEEDS this sorta thing. Should be part of the kit. It's power hungry, and I'm not the only one who's been affected searching the boards..



I'm not using a fuse, and everything else was done from the manual. It's just a lot of load on such a small, long wire from the battery to TEC.

djgiantrobot 03-21-2004 01:35 PM

i'm actually on my way to do some work on mine right now so i'll be over that side of town, i'll give you a call after dinner

j9fd3s 03-21-2004 02:27 PM

yeah get a bigger battery cable. i had sorta the same problem with mine, small battery, the ecu would turn off after cranking for a while. in my case a normal battery fixed it, but it sounds like your cables could be better


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