[777funk]

SOLVED: 98 Misses at first startup-New Plugs and Wires

I have a 98 Vulcan that misses for around 1 minute when first started after sitting for 10 hours or more. It's got new Autolite Double Plats and new wires. I just checked my fuel rail pressure for an injector leak. It was 35 at idle and after shut down it dropped only to 28 or so in 1 hour of sitting.

Where do I look? The car runs good otherwise and no SES light.

 

[wjc]

Sounds like a classic vacuum leak, intake gaskets leak only when cold.

 

[777funk]

Sounds like a classic vacuum leak, intake gaskets leak only when cold.

I wonder why they'd leak when cold? This one has a new LIM and UIM Gasket set as of this summer.

Part of me says don't worry about it and just keep driving it. It only misses for a minute when first started then it runs good. It will miss at any throttle position as far as I can tell and seems to clear up faster if I give it some throttle. It's like it needs a certain amount of revolutions before all 6 will be firing.

 

[777funk]

I'll be looking for an intake vacuum leak. We'll see what happens. I hate throwing parts at the car but I wonder on other things too (injectors, cam sensor, etc).

 

[wjc]

Well if the gaskets are new then never mind. Could be a PCV leak, whatever it is it should set a misfire code eventually.

 

[777funk]

Still haven't had a misfire code as far as I know. I had a DCHP or whatever that is a while back. But it went off and has been for the most part staying off.

 

[esahlin]

Have you had your oxygen sensors replaced?

Any trouble starting after it sits? Does it crank longer to start than usual?

 

[777funk]

No trouble except for the first start of the day. I have had the car for about 6 months and don't know the history on the Oxygen Sensors.


by the way to WJC, I've read a check for a vacuum leak is to spray starting fluid into areas you thin leak around the intake. I did this with a propane torch (unlit but supplying fuel) I went so far as to unplug a vacuum line on the back of the intake and sprayed the propane right into the intake. Nothing happened.

 

[esahlin]

I would try a different tank of gas from a prominent gas station that sells alot of gas.

Stations are supposed to switch to more volatile "winter" fuel and sometimes they dont get it switched or they themselves get a crappy tank from a fuel truck.

There have been lots of complaints of poor idle quality after the car has soaked in colder wether like overnite.....not just whith Fords.

 

[777funk]

SOLVED: Turned out to be a wet plug in the #1 cylinder. I started it one mornging and noticed the missing and shut down right away before it smoothed out. I started pulling plugs and noticed the #1 was wet. Pulled it out and out came fluid (I'm guessing antifreeze and gas). That's why it wasn't firing apparently.

The problem was a head gasket leaking coolant into the cylinder. Changed the head gaskets and problem solved.

 

[sheila]

Glad you got it fixed!

 

[chartmaker]

Just in time

SOLVED: Turned out to be a wet plug in the #1 cylinder. I started it one mornging and noticed the missing and shut down right away before it smoothed out. I started pulling plugs and noticed the #1 was wet. Pulled it out and out came fluid (I'm guessing antifreeze and gas). That's why it wasn't firing apparently.

The problem was a head gasket leaking coolant into the cylinder. Changed the head gaskets and problem solved.

Glad you got it in time.

Guy I know had a F-150 V-6 and he just kept on driving it. Let is sit a few days while he was on a trip. Was hydrolocked when he got back. Sold it beside the road for a few bucks.

No body wants a "truck" with that engine.

-chart-

 

[k8crd]

SOLVED: Turned out to be a wet plug in the #1 cylinder. I started it one mornging and noticed the missing and shut down right away before it smoothed out. I started pulling plugs and noticed the #1 was wet. Pulled it out and out came fluid (I'm guessing antifreeze and gas). That's why it wasn't firing apparently.

The problem was a head gasket leaking coolant into the cylinder. Changed the head gaskets and problem solved.

777Funk,

Just curious, how many miles on the engine ?

 

[777funk]

777Funk,

Just curious, how many miles on the engine ?

167k at the gasket failure & 178k at replacement. Still pretty small leak but glad I got it done.

 

[Mystery101]

My Duratec has the same problem, but its random. Sometimes it happens and sometimes it doesn't.. I'm suspecting the known to be a POS Bosch spark plugs I threw are the cause, Ill pull em to check the next time the missing comes back.
Edit: It started a week after cleaning the TB / MAF from being gunked up from cleaning the EGR C channel..