We are trying to figure out why a 89 Mirage is not starting. After verifying we have sparks, we disconnected the primary wires to the coil, removed the spark plugs and cracked the engine. No fuel came out of the spark plug holes. So, we pulled out the fuel rail with the injectors connected,
(IMG:http://kudria.com/projects/vehicles/mitsubishi/images/89Mirage_01.jpg)
(the injector harness was connected to the injectors when we tried the next step), placed a sheet of paper under the injector tips and cranked the engine. Paper was dry. Thinking it was clogged injectors, we removed them out of the rail, putting a rag under to catch the fuel, and put them in one of those ultrasonic cleaners. When we put the injectors back, they barely made the paper wet -- an improvement but just not what we expected.

We took then one injector out for whatever reason... to find out the fuel rail was completely dry. What could have caused that? Fuel pump fuse? Relay? Where would they be hiding? Is there a quick way to power the fuel pump and see if it is alive? I assume the pump electrical connector is accessible from under the rear seat; am I correct? In other cars I expect the pump the prime the fuel system before you crank the engine but I am not hearing that; it could be the pump is that quiet, but I would like to see if it is getting power.

Anyone?

you may have a faulty electric fuel pump or its relay

electric pumps are usually in the tank or just outside of the tank

you should hear the relay click while its pumping with the turn of the key

the fuel pressure regulator on the fuel rail may also be faulty

search for the repair manual for your model engine etc in the pinned downloadable manual in this forum for help

Unlike most 1993 models and up Lots of 1992 and down Mitsubishi's the fuel pump onlee worked during engine crank sequinces. Ive seen this on lots of older Mitsubishi's like my Galant VR-4 and other 1992 and down ive worked on the fuel pump works onlee when getting a crank signal . Yu can check yur fuel pump relay which should be located inside the underside of the passenger kick panel area. There will be a series of wires. A key on current wire , an always current , a body logic ground and a system signal ground

Chain,

I was reading the manual (book 1, which is the one we have) and it mentioned the pump to be under the seat. That is why I thought the connector was also there, a la Honda. But, I could not find where it thinks the relay is. That is why I chose to ask here. If it was a Volvo 740, I could not only send you a picture of it in the car but also tell the specs.

About the relay clicking, I was originally thinking first a relay would turn the ECU on and then the ECU would close the fuel pump relay once it detected the engine was spinning.

I had one of the injectors out and then cranked the engine for a brief moment. No fuel spilled or dribbled out.



Thanks for the pointers, Kit! I was here frustrated because I could not find the stupid relay. I will check it next time I go there. :grin: :grin:

Update: I found the fuel injection relay:
(IMG:http://kudria.com/projects/vehicles/mitsubishi/images/89Mirage_04.jpg)
Testing it per the the book
(IMG:http://kudria.com/projects/vehicles/mitsubishi/images/89Mirage_06.jpg)
diagram,
(IMG:http://kudria.com/projects/vehicles/mitsubishi/images/89MirageFI-sm.jpg)
Showed me I am not getting voltage on the pin 7 of the fuel injection relay. From the diagram, the starter relay (blue) powers that pin. Where would that relay be hiding? Also, is the item circled in green a fuse? And, how is this interlock switch (red) operated?

Just to let you all know, I did something stupid. You see, when I was measuring the voltage across the relay pins I did not have a reliable ground. Out of frustration, after posting here the last time, I ended up redoing the measurement but this time I used the bolts on the shock tower as ground. Things changed a lot. I also found out where the connector on the engine bay used to test if the fuel pump is getting fuel hides (I took pictures so next time I can find the bastard).

In short, the fuel pump was indeed dead. I stand corrected. Also, the fuel tank was all rusty inside and the fuel sending unit was also boink. So tank came out and pump and sending unit were replaced while I had the tank being cleaned and coated inside (I also took pictures of the tank removal/install and pump/sending unit replace because it was not obvious to just one member of this forum: me. And I do not trust my memory :460: ). So, car now runs again.

Thanks for all the help!