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92 Grand Prix 3.1 Mult port

R

riggle09

New member
I have a 3.1 V6 Multi Port Fuel Injection . I have changed plugs and wires,and coil caps. Also put new fuel pump in it.Plus a whole new exhaust system From front to rear. The car has no power going up hills . Idles fine in park in neutral , when put in gear it hesitates. Also smell gas real bad when you first start it. I'm at my wits end. Don't know what to do next ,can somebody please help me.
 


On the fuel smell. Take a look under the intake where the fuel lines thread in to the rail. That's a common leak area. You can find fuel o-rings at the parts stores in the help section.

As for the rest....when is the last time you did a lower intake gasket?
 
159k

I just recently bought the car because I have a truck and it has very bad mpg wheras the car has better gas mileage. I can't really say when the gaskets have been changed. Two of the spark plugs were soaked in gas when we replaced them, but replacing them didn't really help. I have no clue what to do next, any suggestions are appreciated!

Thanks!
 
Plugs soaked in fuel is typically injectors that are leaking down into the cylinder. Could be as simple as swapping injectors
 


Uh..yeah.

Leaky injector fills cylinder = smell of fuel at startup (from tail)
Leaky injector causes misfire = no power
Runs ok at idle...because you aren't asking anything from it.

It could, I'm no 3.1 expert though. I hate these motors more than you can imagine. personally I think they suck, the 3.4's suck and I'd rather never touch one.

Some folks like them though. Those are the guys you were probably hoping would answer huh? :D
 
Yea OBD-1 . I got a testing system and it throws no codes except to say that it is working. How hard are fuel injectors to change? I have some tools but should I take the car to someone professionally or can this be done in my garage? What tools would I need and where are they located?

Thanks!
 
you would need to pull the upper intake plenum to access the fuel rails. there are 2 rails with 3 injectors in each.


usually just some torx screws holding fuel rails on, or some small bolts. you gotta pull the rails off to swap injectors.


pull the air tubing off, open the throttle up all of the way and have someone prime the fuel pump (aka turn the key on but don't start it) and listen with your ear up to the throttle body. do you hear anything?
 


Well I had an issue with my 90 GP when I couldn't go any faster than 25 mph without it wanting to choke out and die on me. ran fine at idle until i got over 25... tested fuel pressure and spark on all but when I pulled plug wires off one at a time, no change. So I bought a set of injectors off ebay refubished for $87 and it's like a new car again. I got over 273,000 miles on this engine and it the only thing I did with it... still goin strong! So go change the injectors... atleast the ones leaking, however if it was me I'd change them all while you're in there. good luck. Kenny G
 
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