I had a very similar problem, it ended up being the fuel pump even though it was only two years old. Went to start it and fired right up went down to the local 7-11 turned it off got my coffee then when to turn it on and it would fire up then die right out. Got it back to my house, check the fuel pump relay and pump. Relay was good pump was no good. I kicked the gas tank a few times through the driver's side wheel well and then turned the key and it fired right up. Went out and listened to the pump and it wasnt making that continous hummmmm, it was more like hummm, bump, bump, humm. Turned it off then on again and pump ran fine. I repalced the pump and never had a problem since.

Thanks everyone for the info! I just wanted to say I've been short on time with this project. All I've accomplished is hitting the fuel lines with PB oil in case I need to get in there. I do appreciate the help and will update when I make some progress.

-Ray

[/quote]You guys are amazing. [/quote]

I wholeheartedly second this statement!!!!

<img src="/forums/images/graemlins/cheers.gif" alt="" /> <img src="/forums/images/graemlins/kewl.gif" alt="" />

Oh Wise Ones...

Well, she's sat in the driveway long enough. Spiders and wasps are moving in. She deserves better. So after a frustration break I'm back to troubleshooting.

Here is what I have so far:

Early Observations

-Blue spark observed at plugs during cranking (did not test all but there is no combustion going on so I assume its not just one bad plug).

-Pump spins smoothly and consistently when wire is run from battery (+) to test terminal. So, wiring path to the pump is good. Can hear fuel going to engine at engine bay while pump is spinning.

-ECU gives normal A-ok code.

-No tach movement during cranking.

-No fuel smell anywhere even after much cranking.

-Vacuum lines all look good. All (known-to-me) associated electrical connections disconnected and re-snugged. No change.

Observations From This Past Week

-Replaced all E'lytic caps in ecu just in case. I'm comfortable with soldering. No change.

-Took the pump out and observed it shooting fuel out into bucket. *For future reference, if you break the rubber fuel line that goes from the pump to the tank you can get one from Mitsubishi dealer for ~$35. We'll call that a friendly tip, not an admission of guilt <img src="/forums/images/graemlins/smile.gif" alt="" />

-Did the starter solenoid disconnect as suggested by FastEddy. Nothing happens when I turn the key over. No pump activity. Observed that there is no relay sound coming from ecu area. The only click I hear is behind the instrument cluster.

So, at this point I am thinking ECU or a separate relay. I am under the impression that there is a fuel relay outside of the ecu. Correct? If so, anyone have a photo?

Any other tests?

Help! The wife's case for Monty retirement is getting stronger.

Thx in advance.

-Ray

RETIREMENT!? Its only got 205K miles? Its still got another lifetime left in it! ;-) Good luck with the troubleshooting. It can only be so many things! Is the dist pickup triggering the ecu properly? That's about as much EFI-speak as I know- haven't worked on them much.

DOwnload the factory shop manual for the 89 from mitsubishilinks.com. Look in the first volume in the mpi section at the components location. The ecu relay (called "control relay" in the fsm) is on the passenger footwell outer sidewall, iirc. Should have two plugs going into the bottom and pretty fat wires.

If you get stumped, I'm not all that far away and I know Bham (lived there 12 years), and I've got friends who will give me a bed for the night and free beer. I'll travel for gas and a few bucks for labor, a lot cheaper than a shop. PM me and I'll send you my cell number if you want to consult that way.

This assumes you are not an Auburn fan.... <img src="/forums/images/graemlins/evil.gif" alt="" />

geo: Thanks for the tip and for the encouragement!

fasteddy: Thanks for the super generous offer! I'll look into the control relay (no wonder I couldn't find any reference to a fuel relay) and make sure I'm not missing anything that would make me feel really stupid for having you drive all this way. But if that fails I might just take you up on it. Super cool of you. And I'm a Tide fan, BTW. <img src="/forums/images/graemlins/cheers.gif" alt="" />

Next:
I'm going to recheck the ecu traces under magnification, find that relay and check / replace it, pull all plugs and check individually, and relocate those a-hole wasps that have moved into the fuel filler door.

I have some FI relays from 91 Montys if you need them for diagnosis purposes, would just need the OE number for correct relay. You pay shipping...

Nice! Yes, definitely. I'll figure out which one(s) I need and send you a wish list.

Thanks a bunch!

Ray

excuse me if this has been covered,,my dieing computer is not gonna give me time to read thru this thread.

I've had a main relay get all green and corroded on the inside. It containes 2 relays inside. They contoll fuel pump and switch vacuum line switches for charcoal/vapor , egr and such.
When mine went I thought it was ECU 'cause that's how the code read. There is no code for Relay itself.
Junk inside that relay could cause intemntant failure so I wouldn't totally trust the "bench test" for the relay without popping the cover off it to look for corrosion.
If you find a junk yard 3.0 Diamante and Sigma donor, etc,,,the relay with be the same.
Also possible dead internal distrib modual, but that should give cam or crank sensor code.