My 1992 3000gt wont accelerate quickly. Acts like its not getting enough fuel. Does fine when i barely touch the gas, but an more than that and it'll start surging and bogging down. What could be wrong?

Asked by May 02, 2013 at 08:40 PM about the 1992 Mitsubishi 3000GT 2 Dr SL Hatchback

Question type: Maintenance & Repair

The strange part is it does much better when cold. When
the car warms up it acts up much worse. Im kinda thinkin
its the fuel filter. I could tell the car was sittin for a while.
The brake rotors were rusted and the heater smelled bad at
first. And i got the car with the gas tank on E. But before i
replace the filter i want to know how to purge the fuel
system. Anyone got a clue?

8 Answers


So this car was sitting and it's new to you? What do you mean by purging the fuel system? --- Replace all fluids. Replace the serpentine belt. Replace the spark plugs. Replace the air and fuel filter. Pour in some StaBil fuel treatment.

1 people found this helpful.

Fill tank with 93 octane fuel and stabil or sea foam. These cars have to have high octane fuel or they will not run right. I prefer sea foam myself when dealing with old gas. As mentioned above change spark plugs. If unsure of when timing belt was replaced I would pull off the dust covers and examine the belt and tensioner. If tensioner piston is at or over about a quarter of an inch out of tensioner I would replace timing belt. (If it breaks or jumps time you will bend at least six valves). If some else has been working on it before you got it check that plug wires are on coils correctly. Firing order is 1 4 2 5 3 6.

1 people found this helpful.

Not many of these model cars have egr valves. Egr valves on these cars are cal emissions specific. If it was not originally manufactured for cal emissions you probably don't have one on it. Check the back side of the upper intake next to the passenger side fire wall. If equipped with one that is where it will be bolted on.

1 people found this helpful.

you know the accelerator sensor can put a guy in the ditch~ as a 1992 has a lot of wear by now and would not hesititate to condemn this thing...trouble codes when derk92 will tell us everything~

1 people found this helpful.

Good point judge Roy. Missed that one. The Throttle position sensor and or camshaft sensor could also cause these issues he is having.

1 people found this helpful.

I'm thinking now that mitsubishi doesn't want to spend money on vacuum hoses and now after 32 years are crumbly and leaking...always recommend silicone replacements from Gates rubber and trouble with cracking and leakage of controls there~

To purge the fuel system, locate fuel pump in car trunk under the board cover. DISCONNECT BATTERY FIRST,then take pump out and use a small electric pump to remove all old gas.loosen fuel line under front hood and use air to blow all old fuel out of the gas line. before installing old pump or new one make sure the sack filter is clean on the pump and then install pump.Put gas in tank and then turn engine over just a couple of times to get all old gas out of the open fuel line.Rehook up fuel line to NEW fuel filter and try to start up engine.Remove old fuel filter before doing all of this.Good luck.If engine does not continue to run, ck fuel regulator also located under the battery . The Ole' Man.


My diagnosis is the IAC ...I have had a similar problem before it would run awesome cold but when it's at the normal proper running was kinda sluggish not so responsive ..changed the IAC intake air control and that made the world of difference..the porpose of a IAC is to run rich when cold and lean when hot so if a engine is got and runs rich there's your sign...

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