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HELP!!!! Very frustrating. I have a 91 L series wagon with an EA82 carbed engine. If I accelerate slowly - no probs. As soon as I put my foot down it sounds like the fuel bowl is sucking dry - chug chug up the highway. Really embarasing if you try to overtake someone. I have blown out the fuel lines as mentioned in some of the other threads and replaced the filter. I also removed the fuel pump and put 12volts on it to make sure its working.
Anybody have any ideas? How much fuel should the fuelpump pump? Is it worth raising the float level in the carb?

Ive just had my twin carbs reco'ed. The guy found that the "tang" on the back of the floats was adjusted incorrectly. It didnt allow the float to come down very far and hence needle was only allowing fuel in at a slow rate. bowls would still fill to correct level but on a long slow hill under power, or similar, bowls could run dry. Critical adjustment cos if you move tang too far other way, needle can fall out or get stuck.

Cheers. I'll give that a try this weekend or tonight after work of I get time. This is my everyday runner so its gotta be running good.

sounds like the secondary circuit in the carb is blocked,hence no fuel when you go for the second barrel.....this could be an airbleed in the secondary side of the carb,or main jet circuit in the secondary side of the carb..either way ..take it apart and clean it..im sure you will have success,once this is done..cheers

I pulled the top off the carby on Saturday and replaced the needle and seat, and raised the float level by about 10mm. When I lifted the float out, the fuel wasn't even covering the powervalve. I also blew out the jets with some compressed air. Took it for a drive Sat arvo and it went great, you can even feel the second throat open up.
Thought I was on a winner till this morning on the way to work, chug chug chug back up the road. Seems to happen in the cold or wet weather. My old man suggested to take the fuel cap off which did make things a bit better. Must be getting negative pressure in the tank, not letting the pump suck enough through???
Any ideas???

You haven't stuffed around with your emissions systems at all have you? Might try the charcoal cannister?

Otherwise is your accelerator pump in good condition?

I bought it with a cooked motor and dropped a low km import in it. I'm pretty sure all the emission control is all hooked up correctly, and I can blow through the charcoal cannister from the line that is hooked up to the tank.
When you say accelerator pump, are you talking about the carb or the fuel pump under the car near the fuel tank???

I mean the little plunger in the carby that squirts more fuel in when you mash your foot.

Yeah, accelerator pump looked almost new when I had the carb apart on the weekend. The bit I can't understand is why it works fine in the day, but as soon as the weather gets a bit cool it starts playing up. I gave it a good thrashing on the weekend and it never missed a beat until nighttime.

Plugs/Points/Coil?

Have you had a chance to check the A/F mixture at all?

I started with new plugs, leads and coil thinking it was an electrical problem cos it was only happening in the cold/wet, but had no change. Cleaned out the dizzy and cap has no cracks or deep scratches.
When I put the import motor in, I used my original carby because the one on the import motor was full of corrosion, so I had to pull out the little cap that covered the mixture screw and adjusted - no difference. I even put a new stove pipe on thinking the cool air may have been freezing the fuel as it vaporised in the throat of the carby. The auto valve for the warm/cool air works good. If I wasn't bald I would have pulled all my hair out by now. I appreciate the help - please keep any ideas coming - other than getting rid of the car.

it may be a faulty revolution sensor,or bad earth to it..as it sounds like a fuel supply related problem.....the revolution sensor is located behind the kick panel on the drivers side and sometimes they act up a little..this is responsible for fuel pump activation.....these are fitted to carb models...make sure the pulse wire from the coil is going to the revolution sensor is tight and clean...another thing to check..

Yeah check that, it's got a Mitsubishi symbol on it.

That adds up a bit cos every time it rains (when the car plays up) I get a bit of water leaking into the cab from the windscreen seal, and hey, you'll never guess where it runs through.(drivers side kick panel).
I'll try to have a look in there today at smoko
Cheers

Does the revolution sensor vary the voltage to the fuel pump, eg less power - less fuel depending on speed? What would happen if I put 12v direct to the fuel pump. Would th excess fuel go back to the tank down the return line or just flood the carby?

You can chop the Revolution Sensor right out - I did this when I converted to an EJ20.

Wire a relay in parallel to the "START" position on your key barrel along with your oil pressure switch, then take voltage directly from the positive terminal to the fuel pump. This way the fuel pump will come on as soon as you switch the key to "START", and as long as you have oil pressure (ie as long as the engine is running) you'll have fuel pressure. This is important because if you have an accident there's every chance your fuel pump will continue to pump and pump.

There are other ways to do this too, I think there are fuel cut-off devices available off-the-shelf, but this will probably work out cheaper.

Sounds like a plan. I had a quick look and there is two little black boxes just above the kick panel. The screws that hold them down are loose and they are swinging in the breeze. Do you know if they earth through the mounting brackets or via a wire? I've gotta wait till the boss nicks off before I can do some serious looking (about 20mins)

I had a look at the rev sensor hoping to find crap on the plug or a bad solder connection inside. All looks good. I did find a spare car alarm mounted up there though!
This morning (cold shitty weather again) I could floor it through the gears, and can feel the second throat opening up, no drama's until I got to about 80km/h. Anything after that, I had to coast because it started surging for fuel again.
If the rev sensor fails, wouldn't I get no fuel at all??
The saga may have to wait a couple of weeks anyway cos I'm off to Bali tomorrow arvo. Might try a new fuel pump when I get back. Maybe the old one is starting to die. Any recommendations on an aftermarket one.
Thanks for the help

Andrew

I personally like the Bosch VL Commodore one.

Hope you come back in one piece.

I don't think its bombing season at the moment.