Thread: perplexed

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Originally Posted by rspears

I misunderstood that you had a total package from FI Specialties - thought you were using their ECU and harness with an OEM TBI unit. I agree, it sure sounds like you have a gremlin - surprised that FI Specialties has not asked you to send the ECU and harness back to them for check. Sending you a PM with some contact info for a guy at Edelbrock who has helped me a bunch on my ProFlow XT unit.

Good suggestion, will call FI Specialties and ask if they will recheck if I send those parts back. This car spent the better part of three days with the best electrical specialist in the area. So it isn't something like a bad ground. I think the product is defective.

moved the fuel pump back on the frame rail closer to the tank. seemed to run better but only for about a half mile then acts like it is running out of fuel and shuts off

well possibly a return is sensible, but electrical gremblims can be inherint in the vehicle----kit cars especially as the fiberglass(if used) (also on boats) doesn't promote happy grounding of circuits--- items I have seen in electric issues include poor wiring front to rear of vehicle, briaded hoses carrying the current, power coated parts bolted to gether, back feeds thru instruments, diodes dead, resistors---teflon tape on pressure/temerature fittings(biggie!!!!!!!!) sterio and car alarms, remote controls for everything from door locks, remote start, power windows, etc-------

Check the wiring to the ECU, the power and ground in most cases needs to be directly connected to the battery with no switches or other connections between the ECU and battery.

Originally Posted by jerry clayton

well possibly a return is sensible, but electrical gremblims can be inherint in the vehicle----kit cars especially as the fiberglass(if used) (also on boats) doesn't promote happy grounding of circuits--- items I have seen in electric issues include poor wiring front to rear of vehicle, briaded hoses carrying the current, power coated parts bolted to gether, back feeds thru instruments, diodes dead, resistors---teflon tape on pressure/temerature fittings(biggie!!!!!!!!) sterio and car alarms, remote controls for everything from door locks, remote start, power windows, etc-------

Originally Posted by 36 sedan

Check the wiring to the ECU, the power and ground in most cases needs to be directly connected to the battery with no switches or other connections between the ECU and battery.

Both Jerry and 36 Sedan have good suggestions. The system power and ground are super critical, and Jerry's point on teflon tape has caused lots of problems. Another that I thought of is battery capacity - are you running a full size battery with plenty of CCA, and if your battery is mounted in back, are your cables sized to keep your system voltage up during crank? If your voltage at the battery during crank is dropping much below 10V you may not be getting enough spark, or worse erratic firing of the injectors. Just a thought - and another thing I chased on mine... Another thing is the proximity of the ECU to other electronics, in particular an ignition box like an MSD, or even the power to the MSD running too close to your ECU or ECU wiring.