Pulsing idling after sitting in garage for 2 years

[IHAVEAQUESTION]

98 Honda Accord LX-V6.

So about 2 years ago, I got a job in the bay area and had to leave my car in DC. Now I got a chance to relocate back, the first thing I tried to do is to fire up the car. Well, the battery is dead which is expected. But once the car started, the idling has a big pulsing...+-500RPM I would say.

I changed out the MAP sensor and initially the problem went away, but it came back the next day...so, I am not positive what I need to do now. Clean the Idle valve? Throttle body? But the car hasn't been driven for 2 years...how can there be carbon/dirt built up during this time? I actually cleaned them up pretty well before leaving for the bay area. Any suggestion on what else I need to look into?

I also notice black smoke coming out of the back of the engine, which I think requires a replacement of head cover gasket on the rear of the engine. 3 years ago, I had replaced the head cover gasket: https://www.amazon.com/Genuine-Honda.../dp/B00E5O57T6 but this only covers the front of the engine, can someone tell me the part number for the rear of the engine?

 

[RLGL]

One check codes, don't guess
Two Check fuel pressure while running

 

[XavierMace]

Is it 2 year old gas too?

 

[jlee]

Is it 2 year old gas too?

^^^^^^^^^^^^

 

[Burpo]

BINGO! 2 yr old gas turns to a varnish goo.. Need to get that out, or at the very least dump 2 cans injector cleaner in it with fresh gas.

 

[PottedMeat]

I also notice black smoke coming out of the back of the engine, which I think requires a replacement of head cover gasket on the rear of the engine. 3 years ago, I had replaced the head cover gasket: https://www.amazon.com/Genuine-Honda.../dp/B00E5O57T6 but this only covers the front of the engine, can someone tell me the part number for the rear of the engine?

go here: https://www.hondaautomotiveparts.com/ page through the parts lists for your honda and find the gasket. that will list the manufacturer's part number, buy it where ever you like.

 

[dave_the_nerd]

Eew. Sitting in a garage for two years is harder on a car than using it as a daily driver.

 

[sontakke]

On Honda, you need to check the power steering switch/wiring; critter may have chewed it up. It is a green switch hooked up in the power steering line.

 

[slag]

BINGO! 2 yr old gas turns to a varnish goo.. Need to get that out, or at the very least dump 2 cans injector cleaner in it with fresh gas.

Better make it 2.5 to be sure.. and prepare that Fetzer valve with some 3-in-1 oil and some gauze pads. And you're gonna need 'bout ten quarts of anti-freeze, preferably Prestone. No, no make that Quaker State

 

[jmagg]

Throttle Position Sensor.

 

[jlee]

Throttle Position Sensor.

That should throw a CEL.

 

[Meghan54]

BINGO! 2 yr old gas turns to a varnish goo.. Need to get that out, or at the very least dump 2 cans injector cleaner in it with fresh gas.

If the gas contained ethanol, it doesn't any longer (ethanol oxidizes within months if not treated, so it's gone if it was in there). I'd also think about adding some octane booster. It's been said removing the ethanol from 87 octane gas reduces said octane rating to around 82.

 

[Meghan54]

I'd also investigate the true viability of your battery. 2 years sitting uncharged is a recipe for a battery that won't charge worth a darn...or hold a charge.

 

[DaTT]

I'm with the guys above....bad gas.