>>>> 1993 LS400<<<<
Curious...you're the man!...Thanks. You supplied the AMO i needed to start troubleshooting.
Did some troubleshooting today before it rained on my parade and here is what I found....
Check the photos followed by some questions:
This is what I have instead of a Fuel Pump Relay. There is a Fuel Pump Controller module in the trunk. I don't know if that is used instead of the FP relay, but I don't know where else to check for
the FP relay other than here. I Ohmed the terminals of this socket just to make sure, and I got nothing at the diagnostic plug. No voltage is present when the IGN is on either.
***** Brand new Fuel Pump installed 1 month ago *******
This is the Diagnostic plug where I measured for B+ voltage and go 0 volts. I jumpered from FP to B+ and as expected, the car never started. This car ran when it was parked, has had a new FP installed, and a previous mechanic jumpered it some time ago, about a year ago, and it cranked right up. I bought this car to repair some collision damage in the front, Nothing major.Just front bumper, Hood and fender. There is no collision damage to the engine. So my speculation is if there is NO B+ voltage then the ECM is probably bad???? I also monitored for B+ voltage as the engine was cranking over and still got 0 volts. I have another ECM to try but can't open the Passenger door due to the Fender hitting the door, so i wasn't able to get to the passenger area to remove the ECM.
I will tackle this when the weather warrants a nice day to do so. I actually have bought 2 LS400's to fix up 1. One has rear collision damage which I am using to fix the front of this LS. So I still have the other to contend with. It also is supposed to run but I haven't touched it yet. So any ideas are welcomed...I have read the many threads on the ECM but can't find any quite like this problem with NO B+ present. Not sure if jumpering voltage to the FP/B+ jumper will damage anything so I didn't try that without checking here 1st. Hypothetically speaking, If you DO jumper from the + side of the battery to the FP/B+ jumper and it still doesn't start, what next? Oh It will act like it wants to start when starter fluid is sprayed into the intake but I just wanted to make sure it had spark, and it tried to run. Something is just not clicking with this fuel system. I also tried a spare FP relay in the spot where it says "Air Pump"....Nothing... With the Cash for Clunkers deal, i have access to several of these LS400's I got and ECM and a Resistor today for $25. HHHHELP!!!.
Thanks in Advance... Trying to get this car going as a Family car. Incidentally, where is the C/OPN relay that supplies voltage to the FP? Is it one of the two GREEN relays residing beside the ECM
-= BM =-