[nielswheels]

I am getting code P0302. It says cylinder # 2 in misfiring. I changed the plugs, wires, rotor and cap.....whats next? I used AC Delco like everyone said. I read somewhere to look at the Coil next and then fuel injectors.... anything else you guys can think of?????? thanks!!!

2000 Astro RWD Cargo Van

 

[Leeann_93]

Have you looked at your spark? Is it bright blue? If it's yellow, you might want to test your coil. If it's bright blue, it could be the injectors...or it just could be the fuel filter (though I think that would throw the general misfire P0300 code.

What year Astro do you have? Did you check the gap on the plugs before you installed them? I ask because I've gotten 5 correctly-gapped plugs and one incorrectly-gapped plug in a set more often than I'd like to remember.

You might want to try adding some Techron to the fuel if the spark is good before you pull the upper plenum. Sometimes, the poppets get gummed up and the Techron will clean 'em up.

 

[Matrixx]

Hi nielswheels

Might I suggest you head over here:
viewtopic.php?f=4&t=2171
and follow the instructions their to fill out your Signature so we can better help you with your problem, Thanks.

 

[nielswheels]

Ok, today we took the plug out and checked the pressure in the cylinder....it looks good. We checked for a spark at the plug...Check. My friend thinks it might be a vacuum hose or lower EGR might be gunked up. The key here is it is only on ONE cylinder...all the other oners are going fine. Its a throtle body fuel delivery so they must all be getting fuel so the fuel filter has nothing to do with it....any more ideas???

2000 Astro cargo RWD

 

[Matrixx]

HI nielswheels

When you said you replaced Plugs and Wires above, was this before or after the #2 miss appeared? Thanks.

 

[nielswheels]

Hi Matrixx...and thanks for your help. There was a missfire before we instaled the new plugs, wires everything. We tested the pressure in the cylinder thats at 120 to 150 I think. I had a friend bring home this expensive tool that scans all cars and trucks I could see the cylinders firing and the #2 missfired about 4500 all othere ones never missfired. It was getting a spark....so maybe fuel....but why just that one? Would a vacuum leak cause "one" cylinder to missfire?

 

[Matrixx]

Hi nielswheels

-120-150? hmm, that's not good. Can you recheck that?
-Check the distributor shaft for play
-Check fuel pressure (58-62 PSI (key on engine off)) and bleed down (no more than a 2lb drop for every 10 minutes)
-I'm thinking a sticky valve or a faulty injector or injector wire, but nothing can be left to chance.
-Yes a vacuum leak can cause a cylinder to misfire.
-Check the MAP Sensor for vacuum leaks (located above cylinder #2).

These are the first things I would check and eliminate.

Please keep us updated, Thanks.

 

[nielswheels]

Where would the faulty injector, or injector wire be located? My friend want to pull the intake manifold and have a look. ! Seems like a lot of work if thats not where the problem is. it only has 54k miles on it so.....I just dont know if the guy that owned it just didnt take care of it or what? Thanks

 

[Matrixx]

Hi nielswheels

Removing the Upper Plenum isn't that difficult to do,no. It's plastic and cracks very easy so being careful is paramount here and not over torquing it. At least you will get a good view of things for sure. You may only have 54k on it, but it's nearly 9 years old. You can replace individual poppets if need be, but I would recommend upgrading it to the new style injector system if you do plan on replacing it. I would also replace the regulator while your in their if you do choose to go that route of upgrading.

Just something to think about and I'm sure others will chime in if they can.

If you have anymore questions just fire away, we will do our best to help.