Stock GVR4 running rich and rough under 3k rpm and sounds like lawnmower

[R4CERX]

Hey guys,

I've been DD'ing my Galant for about 6 months now with no issues. Its all stock and one day I started it up and it sounded like it was missing and smelled really strongly of fuel inside the car. Also it runs really bad below 3k rpm and tries to die but besides sounding bad it drives fine in upper rpm. I checked plugs and wires and checked for any leaking fuel didnt find anything amiss. Unplugged the MAS and it ran worse to rule that out. And checked all vacuum lines and everything seems to be connected. Any ideas or suggestions are appreciated.

Daniel

 

[toybreaker]

wires broken at ecu temp sender down on the t-stat housing

... or

torn diaphragm in the fpr

 

it sounds like one of the plugs isnt firing.

if it runs like crap during idle:

Pull out one plug wire at a time, the one that doesnt change how the car is running will be your issue.

If pulling a plug makes the car stall or run worse, those are okay.

from there i would pull the plug, if it looks bad might as well replace. then check continuity in the plug wire. from there check the coil for that plug.

Im willing to be 90 percent your problems lies within those few things .

let us know how it goes.

 

[toybreaker]

o.p said he just changed the plugs/wires, and he *probably* would have noted a single cylinder issue by the coloration of the plugs /ubbthreads/images/graemlins/dunno.gif



... also, on these cars, pulling a single plug wire disables two cylinders

if you want to kill a single cylinder, do it with a logger/unplug individual injectors.


My bet is on ect or fpr /ubbthreads/images/graemlins/smile.gif

 

[TomN]

I would start with the coolant temp sensor.

 

[prove_it]

Ditto, also to the OP do you smell burning in the cabin? Could possibly be leaking caps.

 

[R4CERX]

Thanks for the suggestions so far guys. I'll have to check on it when I get home. And I checked the ECU and caps are fine.

 

I dont see how pulling a single plug wire will disable 2 cylinders?

"sounds like missing and smell of fuel"
sounds like its not burning the fuel in one cylinder. by pulling each plug wire one by one and observing any changes in how the car is running, it should point out where the miss is coming from.

It just something to check though, it could really be so many things on these cars

 

[pot]

Pulling a single spark plug cable will disable two cylinders b/c the ignition system is a wasted spark system.

 

[etownpips]

You also could start by doing a compression test it to make sure its not an internal issue. Like a bent valve.

 

[Wizardawd]

Quoting Pot:
Pulling a single spark plug cable will disable two cylinders b/c the ignition system is a wasted spark system.



Doesn't mean that the other cylinder on that coil pack doesn't work. It still fires just fine. Wasted spark means that 2 spark plugs are fired at the same time. One during the compression stroke, the other during the exhaust stroke. You may be confusing the fact that on a 4 cyl car that one cylinder disabled effectively cancels any power made by another cylinder due to the opposing power strokes.

Wiz

 

[pot]

Understood Wiz.

 

[prove_it]

Your still better off dropping an injector to prevent fuel loading and possible ring wash.