Engine cutting out, tach cutting out and minor vibration.

[spaztic_typer]

I have a 2000 Explorer with the 4.0 single over head cam. Once in a while the engine skips or hesitates. I believe it's slush from the road hitting something in the engine. The inner fenders are not installed. Now it seems to have a vibration, under acceleration and the tach is acting funny. I take my foot off the gas and no vibration. I put it in neutral while driving no vibration. This is all under winter conditions. So I've pretty well eliminated the drive train. I'm guessing, crap off the road has, or does spray up into the engine compartment, causing the skipping. Also I'm guessing the wires or cap are getting bad. And as a result also the tach has a bad contact. The skipping of the engine hasn't happened in a while, but I haven't been through piles of slush lately. I'll also add that at an idle the vibration isn't there, it comes on while driving. I'm guessing the ignition is breaking down. The more you apply the gas at highway speeds the more the vibration becomes. It's not real bad, like a cylinder missing though. What are your thoughts? Get a cap and wires?

 

[2000StreetRod]

distributorless ignition

If the "cap" you're referring to is a distributor cap then you won't find one because your engine has no distributor. It has an electronic ignition system and the timing is controlled by the PCM. The crankshaft position sensor is located next to the crankshaft harmonic balancer and is subjected to road grime as well as slush. I suggest that you clean it by disconnecting/reconnecting a few times. It is accessible from under the engine.

 

[spaztic_typer]

Thanks will do, I'll get to it on the weekend and post my results. Does it have any effect on the tach?

 

[2000StreetRod]

tachometer reading

The PCM generates an analog signal to drive the tachometer. If the output from the crankshaft position sensor is erratic or absent the PCM can't determine the engine speed to display on the tachometer.

 

[spaztic_typer]

Excellent! If it stops snowing long enough this weekend, I'll pull that connector off and clean it up. Also look for for other weather worn components.

 

[spaztic_typer]

Okay I had a chance to stick my head under the truck and found the sensor. I wasn't able to get to it, as there were a number of objects in the way. It does look to be in okay shape, not rotted or cover in crap. I didn't get it off, so I didn't inspect it to that point. I did though find a leaking lower rad hose and a oil leak coming from the front right axle....lol That's a whole new post though. I sprayed the connector with wd 40 and road tested it, no improvement. The truck comes off the road once winter is over, (hopefully soon) and I'll look at it then. Just curious if I should check the fuel filter, and also see if the voltage to the distributor pack is proper, I'm thinking the ignition could be crapping out.

 

[spaztic_typer]

The temperature dropped a lot today and the truck is running much better. Mind you the tach is still messed up, but thats secondary. This can be a sensor of some disciption?

 

[2000StreetRod]

tachometer symptoms?

Please describe the "messed up" tachometer symptoms.

 

[spaztic_typer]

It bounces around when first started, then seems to settle down. I have a 15 minute drive to work.

 

[2000StreetRod]

loose connection?

Maybe there is a loose connection between the crankshaft position sensor and the tachometer. Make sure the PCM connector retaining bolt is snug but don't overtighten. Then check the main engine harness connector retaining bolt.

Do you have a message center? If so, the PCM tachometer signal goes to the message center as well as the tachometer.

When the engine is idling does the tachometer jump back and forth between two values? If so, what are they? There's a wire that selects between V6 and V8 connected to the tachometer. Maybe it is loose.

 

[Runnin'OnEmpty]

.....The inner fenders are not installed. ......

Reinstall the inner fenderwells. If the plastic ones are
missing, get some from a wrecking yard. The rubber
splash guards are cheap from RockAuto.

The engine needs protection from the slush you're
driving around in...

 

[spaztic_typer]

I do have the original inner fenders and will put them back on, once the 2 ft of snow and 0f temperatures go away. This morning it was 9f and the truck ran well. The tach jumped basicly from 0 to 3k for the first couple of minutes and settled down to normal. I will also look into the bad connections when it warms up. The thing I did notice is that in cold temperatures like this morning and last night the truck had no vibration, ran like it should. I don't expect a warm up for a couple of more weeks, and I get back to you guys then. The vibrations started when it warmed up to the lower 30's. It sounds like it maybe be running rich in warmer temperatures? No I don't have a message center that I know of just idot lights. It's an XLT if it should have one I'll figure out how to work it. And thanks guys I appreciate the input, I'd work on the truck now but this winter has been a killer and it's just impossible to do anything in 14 layers of clothing and 3 sets of gloves on at 9f with a wind chil of -10.

 

[2000StreetRod]

3K at idle?

Was the 0/3K indication when the engine was at idle?

 

[spaztic_typer]

It will bounce from 0-3k max, while running down the road. I usually run at 50 mph which would be about 2k. It doesn't bounce wildly all over the place though. I stays with in normal running speed. Another cold day...no vibrations! yah baby.

 

[2000StreetRod]

my guess

If it normally stays at 0 and then shoots up to 3,000 and then immediately drops back to 0 I guess there is a loose connection.

 

[DjDom]

Just curious, where in Ontario are you?

 

[spaztic_typer]

Acton

 

[bluestream1]

Does it do this when it snows? Its a known problem with these trucks that if the air cleaner cover does not fit tight, or if the bottom plastic piece bows out with age, that snow will get sucked and and hit your MAF sensor. This causes the hesitaion, or "bucking as some call it. It took me some google searging to find a great thread from a Ranger forum before I found a fix for my own truck Runs great now...

 

[spaztic_typer]

The engine has stopped running rough, I have no idea what the cause was.The engine hasn't stuttered in a couple of months. The tach is still jumping around, but I'm figuring it's a back connection....spring when will you arrive?????

 

[spaztic_typer]

I have figured it out, it's the actual tach sticking, so I'll have to remove it and see what's causing the issue. Can I assume I can pull the trim off the face of the cluster to get at it?