Strange No Start Problems (Fuel Related)

[femmeDSM]

So I am about to throw my car into the lake...........

I bought the car w/ a bad fuel pump that was keeping her from starting...Replaced that, as well as a lot of other things (to be listed below), but still not having any luck getting her to fire up. A lot of what's going on has been addressed in this thread:
http://dsmtuners.com/forums/showthread.php?t=207151

...but I figured I would start a new thread for "Round 2", since my original problem (Fuel pump issues) has been solved.

For those just tuning in, here is a basic overview of what's going on:

Keep in mind that the car hasn't started in about 8 months now (I've owned for ~5).

-------------------------------------------

- Replaced Fuel Pump (Walbro 190)

- Re-Wired Fuel Pump

- Replaced ECU

- Car has compression (138-138-138-148, keep in mind this is a cold reading & the car has been sitting for several months -- not too bad)

- Car has spark on all cyl.

- Battery is new

- Alternator is new

- Replaced every fuse (yes *every* fuse in the car)

- Injector resistance tests within specs

- "Plugs" on top of injectors (sorry, not sure what their technical name is ) are getting between 10.8 and 11.5 volts when cranking

- Injectors have been tested off the car (via hooking up to AA battery) -- they definitely spray.

- Only time engine will start is via Starter Fluid (starts right up w/ this, no hesitation).

- Fuel is getting to the fuel rail (pulled hose from rail, cranked the car, and fuel shot out like a jet)

- No fuel is coming out of the return line while cranking

- With ignition KOEO, no battery voltage is present on any of the injector pins on the ECU (unless I'm doing something wrong, which wouldn't be surprising )

- When cranking, I can occasionally hear a 'clicking' sound coming from the top of the #2 injector...Almost has a sound similar to a bad relay, or an electrical connector that's not seated properly. The plugs (again, don't know what these are called -- someone please enlighten me) look a bit chewed up, so it's hard to get them seated properly onto the injector. I've gone so far as to physically hold/push them down while a friend cranked the car, but that accomplished a whole lot of nothing......

-----------------------------

So, okay.....Anyone wanna take a stab at this? I am at my wit's end, and am this close to picking up the phone and calling (gasp!) a mechanic.

 

[TimG]

So fuel is getting to the rail but not coming out of the regulator return. This makes me believe:

1. Issue with the lines; leak or crack. This would cause a lower fuel pressure, which may be so low, it won't start the car.
2. The FPR is non-functional and won't open, causing the pump to overwork itself and possibly trash itself.
3. Your injectors are not good.

Check your plugs for fuel on them.

 

[femmeDSM]

So fuel is getting to the rail but not coming out of the regulator return. This makes me believe:

1. Issue with the lines; leak or crack. This would cause a lower fuel pressure, which may be so low, it won't start the car.
2. The FPR is non-functional and won't open, causing the pump to overwork itself and possibly trash itself.
3. Your injectors are not good.

Check your plugs for fuel on them.

Thank you, I appreciate the (quick!) advice.

The thought crossed my mind that it could be the pressure regulator, but since I have actually never heard of a FPR being *so* bad that a car wouldn't even start, I figured the chances of that were slim. I suppose anything is possible in the world of DSMs though.....

Each time I crank the car, I thoroughly check for any signs of leaks (spots on the ground, any strong fuel smells) and have never found one. I haven't hooked up a pressure gauge to the line yet, but judging by how forcefully the fuel has been coming out of the line into the rail, pressure doesn't seem to be low at all (going into the rail, anyway).

As for injectors, I thought they were bad, too, until we unhooked the rail today and sprayed carb cleaner/compressed air through them...They definitely open when I apply voltage to them, and the carb cleaner sprayed out better than expected. (for reference, i also replaced the O-rings when I did this).

The plugs have a bit of a gas smell, but I don't see any gas on them after several rounds of cranking....

 

[steve]

- No fuel is coming out of the return line while cranking

- With ignition KOEO, no battery voltage is present on any of the injector pins on the ECU (unless I'm doing something wrong, which wouldn't be surprising )

Pull the regulator and soak it too. Test the return line using the fuel pump check connector rather than the starter.

Please explain what you did to test for voltage from the injectors at the ECU. This could be a big clue. If the rest of the injector circuit is good you should see battery voltage at each of the four pins until the ECU tries to fire an injector.

I put your logger cable in the mail earlier in the week, it should show up anyday.

Steve

 

[femmeDSM]

Pull the regulator and soak it too. Test the return line using the fuel pump check connector rather than the starter.

I will do these tonight. Is there anything special I should use to soak the FPR, or should the carb cleaner work for this?

Please explain what you did to test for voltage from the injectors at the ECU. This could be a big clue. If the rest of the injector circuit is good you should see battery voltage at each of the four pins until the ECU tries to fire an injector.

Unplugged the middle wiring clip, grounded the black pin to a bolt on the chassis (tried a few different ones in case I wasn't getting a good ground), touched red pin to pins 51, 52, 60 & 61 on the ECU w/ KOEO. I got the pin #s from my Chrysler FSM (1990). When I didn't get any voltage, I tried moving the probe around to a few different pins, and got 0v on all of them that I tried.

I figured that I might have been doing something wrong, so I tried the same technique on the corresponding pins on the wiring plug...Same results there.

I'm sure I screwed this up somehow....Don't laugh at me -- I was just trying to be logical. Electrical stuff confuses me... .

I put your logger cable in the mail earlier in the week, it should show up anyday.

Thank you! I'll let you know when I get it.... Please let me know what I owe you.

 

[steve]

I will do these tonight. Is there anything special I should use to soak the FPR, or should the carb cleaner work for this?

Carb cleaner should be fine. this is just to try and free it up incase it's stuck. I guess I'd also try blowing in the return port with some compressed air to see if it comes out the rail fitting and to pop the valve off it's seat.
Do I remember you changing the fuel filter?

Unplugged the middle wiring clip, grounded the black pin to a bolt on the chassis (tried a few different ones in case I wasn't getting a good ground), touched red pin to pins 51, 52, 60 & 61 on the ECU w/ KOEO. I got the pin #s from my Chrysler FSM (1990). When I didn't get any voltage, I tried moving the probe around to a few different pins, and got 0v on all of them that I tried.

You want to be checking these pins at the connector while it's plugged in because removing the middle connector also disconnects the ECU from the MPI relay (pin 56) so that the power to the injectors never gets turned on.
http://www.vfaq.com/mods/ecu-harness-1G.html

Steve

 

[BobPell]

...but I figured I would start a new thread for "Round 2", since my original problem (Fuel pump issues) has been solved.QUOTE]
Not to worry, every decent fight goes at least six rounds!!!

 

[femmeDSM]

(Not so) short update...

I think I may have found a big part of the problem (if not the whole problem)...

I soaked the FPR in carb cleaner overnight. Filled up the air tank, and tried to blow some compressed air into it, and.....nothing. I wasn't sure how much pressure is required to open it up, so I gave the Mitsu dealership service dept. a call and asked them (hey, why didn't I think of that before!?)....I was told ~20-25psi should do it....I was blowing probably 40 lbs. of air directly into the return port, and nothing was coming out anywhere.

Logically, I guess that would indicate that it's shot, huh?

At least that explains why no fuel is coming out the return hose.......

We asked my new "friend" at the dealership whether he had ever heard of a bad FPR causing a car to not start, and he answered, basically, yes. As I understand it, when the pressurized fuel is reaching the rail, the (bad) FPR is creating a vapor-lock which isn't allowing fuel to enter the rail, and it's just basically bleeding back into the fuel line, rather than entering the fuel rail and hitting the injectors...That would also explain why, when we remove the fuel line going into the rail, the fuel is not pressurized at all. From what Mitsu Dealer Service Guy said, if the FPR was doing its job, highly pressurized fuel would be shooting everywhere when we unhooked that line (which is kinda what I was thinking it should have been doing, too).

So that's a $100.00 part that I need to order....I would try a junkyard or used parts house, but I'd rather just spend the extra money for the peace of mind and give it a try.

I'll still be checking the ECU injector pins tonight or tomorrow morning (ran out of time last night), and will report back.

Does any of this sound feasible to y'all? It made total sense to me when the guy was explaining it....The little light-bulb went off in my head, and I was like .

 

[eclipse_20g]

Sounds like you've found the problem. Order the FPR and get that thing on the road!

 

[femmeDSM]

Thought I would update this post to let everyone know that....
SHE LIVES!!!

Turned out to be what is probably the single *stupidest* problem to ever plague a DSM -- a dirty fuel tank.
I replaced the FPR (twice) and rail (twice), along with virtually every other component in the fuel system. When it still wouldn't start, I went back to pull the fuel pump again to check the O-ring (after pulling out all my hair). When I did, I shined a flashlight down into the gas tank, and it was gross, guys. Chunks of rust floating around, pieces of green (???) stuff, and lots of sludge built up on the bottom of the tank. It looked like I was looking into dirty lake water. I guess trying to start the car kind of stirred up whatever was lying around down there, and it was clogging the in-tank filter immediately whenever I tried to start the car. When I origianally replaced the fuel pump, the tank looked a little dirty, but certainly did not look this bad.

We dropped the tank, drained out all the old gas, took the (empty) tank to a car wash and sprayed it with high pressure water to break all the rust loose ( ... ).

Filled the tank with a few gallons of premium gas, a bottle of 15 point Octane Booster and about 1/3 bottle of Seafoam.

She fired right up, for the first time in almost a year, just like nothing had ever happened.

Go figure.

I seriously shed a tear, guys. Talk about a relief. Haha.

She drives great, but is hard to get started occasionally. I have traced this problem to faulty wiring at the coolant temp sensor. When I wiggled the connector, the wires just came off in my hand. The previous owner decided that electrical tape would be a good way to hold the wires in place, and obviously did not do a very good job of setting this up, so there is no telling how long the wires have just been barely making contact w/ the pins. I now have to re-wire the sensor, as the factory wires were cut too close to the wiring clip to re-splice them.

All that said...If your car still doesn't start after 2 months of troubleshooting the fuel system, CLEAN THE STUPID GAS TANK. I am still kicking myself for not doing this sooner.

 

[Old Mitsu Tech]

You will be a shining light for those of us who tend to over look that.

You will be to fuel tanks that Defiant is to crank pulleys.

Great Job. Nothing like seeing a job well done.

 

[femmeDSM]

You will be a shining light for those of us who tend to over look that.

You will be to fuel tanks that Defiant is to crank pulleys.

Great Job. Nothing like seeing a job well done.

Thanks

My only hope is that someone else can learn from my mistake and save themselves the trouble and headaches of dealing with such a stupid problem.

It feels great to have a running DSM again. I Seafoamed her tonight, and she runs like she just rolled out of the showroom floor, minus a few small 'quirks'. Damn, do I feel lucky

 

[femmeDSM]

By the way, I hereby move that my Forum Title be changed to "Fuel System Wiseman". . j/k

 

[steve]

We'll see what we can do about that.

Steve