Code 300: Random misfire

[longyard]

Anyone know the most likely cause for this issue? Just showed up today.

[Phantom]

Distributor cap is what I hear that is most common , the short design limits ventilation , make sure you get a high quality cap and rotor preferably with brass terminals and there are vents in the distributor housing that have screens that get plugged up and need to be removed but there are other causes as well

[NY Safari TONKA]

What was the last things done to the van?...

[longyard]

What was the last things done to the van?...

Just completed:
1. power steering pump
2. Water pump
3. Fuel pump
4. All new fuel lines
5. New harmonic balancer
6. New radiator
7. Upgraded alternator to 200amp
8. New idler and tensioner pulleys

[longyard]

What was the last things done to the van?...

Just completed:
1. power steering pump
2. Water pump
3. Fuel pump
4. All new fuel lines
5. New harmonic balancer
6. New radiator
7. Upgraded alternator to 200amp
8. New idler and tensioner pulleys

Oh... and I upgraded the sparkplugs to NGK irridiums. I've driven the van very little, and so am not very familiar with it. Really today is the first drive I've taken in it since I drove it home two months ago (100 mile trip, no issues.) I should note that it was very humid, and sometimes rainy, today, which lends credence to the distributor cap theory.

[gillbates]

I had the same problem whenever it rained. Changed the cap and rotor but it still kept refusing to start in wet conditions. One day when it wouldn't start I pulled the dog house and cranked it. I heard an electrical clicking. When I looked at the engine while cranking it I could see a little lightning bolt shooting across the top of the coil. I replaced that and was good to go. I'm not saying you need a new coil, but I think it would be worth it to pull the cover and crank it on a day when it won't start.

[longyard]

I had the same problem whenever it rained. Changed the cap and rotor but it still kept refusing to start in wet conditions. One day when it wouldn't start I pulled the dog house and cranked it. I heard an electrical clicking. When I looked at the engine while cranking it I could see a little lightning bolt shooting across the top of the coil. I replaced that and was good to go. I'm not saying you need a new coil, but I think it would be worth it to pull the cover and crank it on a day when it won't start.

Thanks Gill. I'm going to get a new coil to add to the new distributor cap I bought. Is it hard to change the coil? Thanks. Bill

[Leeann_93]

Nope, easy-peasy.

[longyard]

Nope, easy-peasy.

Sounds like I know what I'm doing this weekend!

[NY Safari TONKA]

Ok look here make sure your timing its god chk complete w/Tach....if problem still CHECK YOUR CRANK SENSOR ...Let us know how it goes....You can chk the voltage on the sensor (at connector Pink or Lt Green wire) w/key ON car off should have about 11.5 Vlt...if any chk blown fuse + wires...

[longyard]

Ok look here make sure your timing its god chk complete w/Tach....if problem still CHECK YOUR CRANK SENSOR ...Let us know how it goes....You can chk the voltage on the sensor (at connector Pink or Lt Green wire) w/key ON car off should have about 11.5 Vlt...if any chk blown fuse + wires...

Okay. Can you tell me if timing the beast is as simple as lining up the marks on the timing cover and the crank balancer? Those are the only marks I see.

[gillbates]

I don't think there's much you can do with the timing on an 01 as the distributer only goes in one way. It's not like the good old days when you could loosen it and move it back and forth. Damn computers.

If you do change the coil, and you still have the original, you have to drill out the rivets that connect it to the brace. The new one will come with bolts and nuts. But like I said before, while that was my issue it might not be yours. But pulling the cover and cranking it while it's in non-start mode may (or may not) help you find out.

[NY Safari TONKA]

Can you put up a pic (distributor area) to see for sure what systm you have if EDI (no timing)...if HEI (timing)...I blv after 1995 was the EDI...the misfire it signal by the Hall Effect

[longyard]

Can you put up a pic (distributor area) to see for sure what systm you have if EDI (no timing)...if HEI (timing)...I blv after 1995 was the EDI...the misfire it signal by the Hall Effect

I've got a 2001 and the distributor doesn't look like any HEI I've dealt with before. I don't mind replacing parts on a vehicle that's got all it's original stuff after 130K and long exposure to salt on the roads from upstate NY. (I'm down here in NC.)

[rev_les]

The timing is non-adjustable. One other area to look at is the distributor gear itself, these motors are notorious for eating up distributor gears.( I have 3 of these vans, and I've had to replace the gear on 2 so far). If you see ANY groove worn in it, replace it.

[NY Safari TONKA]

Ok Im looking back at what you have change vs old school mech.... ...when you get a code P030x its at one of the cyldrs...but a P0300 its on ALL... ...What moves in all cyldrs?...SO THATS THE ANSWER FOR YOUR PROBLEM ... ....ANYONE!!! for a VICTORY BANANA DANCE

[NY Safari TONKA]

...DON'T...Parts to chk for this problem = Vac Leak...Your Fuel Pump or Your EGR..IF After AFTER MAKING A 100% SURE ALL ARE WORKING if problem still let us know

...Remember code P0300 its at ALL CYLDRS = FUEL/AIR MIX

[rev_les]

...........There are numerous causes of a P0300. It's more than likely ignition related.

[NY Safari TONKA]

Would you say, when it is ignition related its P0300x (x=cylndr #) ... ...But when its P0300 (code comes by itself not with other P0300x) ITS A RANDOM MISFIRE....Bcs its MISFIRE thats where people say it ignition related

All IN A CAR THAT WONT START ITS IGNITION RELATED =NO IGNITION NO BOOM!

[rev_les]

It can be fuel related, but more often than not, it's ignition related. Go buy yourself a factory service manual. If the engine runs and the fuel pump is not up to correct pressure, one symptom people usually mis-diagnose is that they have a transmission problem. This ISN'T your dads Oldsmobile.