Funky Idle

[KevinKernaghan]

I have a 1995 2WD Pathfinder which has a little trouble maintaining a steady idle. There aren't any major fluctuations, but it's unnerving to watch the tach repeatedly dip up and down at traffic lights in normal temperatures.

 

I don't know if the fuel system has ever had a filter replacement or not, what's the best procedure for that and how much of a PITA will it be?

[vengeful]

I would do the following, in order of cheapness.

 

Clean the Throttle Body.

Run a bottle of fuel injector cleaner through your tank.

replace the fuel filter.

 

Since you don't know the last time the fuel system was cleaned out, I'm going to presume that you haven't replaced the fuel filter in a while either. I would go ahead and do these things anyways, as they will certainly help with gas mileage a little.

 

If none of that solves it, you may have a more serious issue. Could be the Idle Air Control Valve (IACV-AAC), throttle position sensor, cold start valve, or a number of other things that contribute to idle. Is the check engine like illuminated?

[KevinKernaghan]

Yeah, I'm pretty sure the fuel filter is probably worthy of replacement. I'm reading up on it my Chilton's guide right now. As for the check engine light, it is not illuminated. I'm also going to go inspect the MAF sensor here in a little bit, I've heard that can give some improvements, but maybe not in idle quality.

[vengeful]

How many miles does the truck have?

 

Might be worth it to clean the wires in the MAF, too. See the pinned topics at the top of this forum for a how-to on that.

[KevinKernaghan]

it has about 125,000 miles. Yeah, the MAF sensor is getting cleaned today or tomorrow

[vengeful]

When was the timing belt last changed? That shouldn't have an effect on your idle, but at that mileage, if it hasnt been done, you need to do it ASAP.

[KevinKernaghan]

Woo! I totally just rounded off a screw head on that MAF sensor....Those heads are quite fragile. This will be fun to fix.

 

The timing belt, I'm hoping, will get replaced this christmas when my father and I are doing it myself. All it has to do is putt around town for a few more months and then make a 5-hour trip from Lubbock to Dallas and we'll be set. We'll probably get the water pump too, as long as we're around there.

[Precise1]

I wouldn't put off the timing belt... These are interference motors, and several members have trashed their motors lately due to this.

 

B

[vengeful]

Woo! I totally just rounded off a screw head on that MAF sensor....Those heads are quite fragile. This will be fun to fix.

If you have access to a Dremel, you can cut a slot through the screw, and use a big slotted screwdriver instead of the phillips. That's worked for me in the past, and saves having to cut off the head and drill it out. Once you get the screw out, replace them both.

[Slick]

I just did my MAF sensor as I was getting a high/uneven idle too..and now all is well... and I agree with the guys on the t-belt.... the one part that shouldn't wait

[revgolem]

Another thing to try is "Sea Foam", works wonders to clean the top half of the engine. you just pull a vac line and stick it in the bottle (getting just a little at a time so you don't kill the engine). suckes it right up and cleans great. you WILL smoke out the neighborhood though... so if you have any nosey neighbors with itchy 911 fingers you might want to let them know.

[Casey.T]

Ya what ^^^^ they all said.

 

Timing belt, ya that too...........

[Revco]

Listen to CaseyT & the others...trust me. Few hundred for a T-Belt is *much* better than $2K+ for a new engine if it breaks.

 

If you have a shop do it...have 'em do the water pump and pull the rear T-Belt cover to check the cam seals for any leaks. Might think about having them replace your other belts when it comes back together.