Truck died while driving low speed, cranks but not even a sputter. Starting fluid wont run it either, so no fuel or spark. Posted 2yrs ago about different stalling issue, never resolved, found if fuel pump connectors are unplugged then plugged in it "reset" the pump? Been doing that for last 2yrs. (only happened handful of times). but not today. figured pump finally quit, but starting fluid didnt run either. That got me thinking. of course checked all fuel pump/injectors and "multifunction" fuses. all ok. BUT, Scan tool wont recognize ECU and the check engine light wont come on when ign on?

Unplugged and cleaned all ECU connections(they were immaculately clean, didnt need it, but im desperate!) removed both ECU panels as i resd previously, again no corrosion. siliconed panels on for added security.

so most likely ECU? This is my thought. but i read someone replaced a fuel injector relay? With similar issue, in addition to ecu, and it worked. Obviously whos to know what was bad?i know where the relays are on RH side behind glovebox, but they arent clicking.

Sorry for rambling. wanna give all info related. i'll check grounds tomorrow. (also suggested in similar post) thanksin advance

 

Be sure the MAF is plugged in real good.

Multi-function relay on fender wall ahead of ECU wall is one place to check, it controls fuel pump. Also be sure inertia crash switch on firewall is reset. There is a pressure test port (tire valve) on the passenger fuel rail. A simple tire gauge will tell you if any pressure there, should be 32-34 PSI when pump is running. Pump should run for a couple of seconds when you switch ignition key to position 2.

Fuel injectors get plus battery voltage common to all of them. The ECU grounds them to make them squirt. So you can meter to check for a bad relay or fuse.

You have not stated the year. If distributor year, you have an ignition amplifier module that can make no spark, as well as distributor itself. If later years, with four small coils at back of engine, those have a single connector on the driver side, and again they get plus battery when keys is on, and ECU grounds them to make the spark.

There are fuses under dash. There are fuses under hood. There are bolt in fuse links also in the underhood box that are "master" fuses for groups of the fuses under the dash. The RAVE electrical manual is your friend. F3 under the dash on satellite panel 2 powers the OBDII port. The ECU will have more than one fuse involved. Start fresh by checking every fuse with a meter or test light.

Take a battery jumper cable and attach to negative battery post and other end to metal on the engine, this will bypass a loose block to frame ground.

 

Thanks for the suggestions. its a 98. already checked coil pack(s) for connection. Fuel pump is not running with ign on. Checked the multifunction black box thingy ahead of the ecu on rh fender. I'll check the inertia switch and the pressure port. But like i said its wierd no CEL with the ign on. That makes me think ecu or ground

 

Well, the Multi function relay controls the fuel pump with the inertia switch in series. But the ECU controls the multi function relay. The ECU also makes power hot to all the injectors thru another relay. So if none of these relays are being operated, the ECU is certainly a common thread.

 

I have the Rave manual on my laptop. might have to bring it down here to my work this weekend to see where i SHOULD be getting power. kinda time consuming just unplugging stuff, cleaning and reinstalling with lithium or dielectric grease, all for no change. Tried the 1515( eka?) thing. with key fob and manually with key. No change. also thought that was the issue (immobiliser) due to not driving it for one week, then go to drive it, and key fob didnt work? Battery is few weeks old. used door key, started and drove fine until this. (later that day) now i pulled the battery on key fob and rein!stalled it, now it works? Dam Lucas elec.

 

Lucas - Lord of Darkness

 

ITS ALIIIIIIIIIVVEE!!!!!!