I have a 03' H2 with a Magna Super Charger (here's the web site for those who may be interestedhttp://www.magnacharger.com/sc-hummerh2.htm) which has been working great for over 3 years. However just recently I started noticing a slight engine misfire when the engine is idling, and then today when I started the engine the missed fire was very evident. The engine RMP goes from around 1000 down to 350 and back up. I have a Hyper Tech on board (http://www.hyperpac.com/) and when I check for codes it read P0300 which says "Radom/Multiple Cylinder Misfire Detected". Can anyone direct me to the most likely area to check out? Has anyone ever experienced this problem?

 

thats the same code that h3's get when they have to get a head replacement. not sure on your h2 but I would have it checked out quick.

 

Thanks for the tip, I hope thats not the case. I'm having a Tech look at this week. I'll let you know what we fnd out.

 

Maybe plugs or plug wires..

 

HOPEFULLY!!!![:@]

 

could be many different things that cause a misfire but that code just makes me cringe

Didn't mean to make you nervous with my original answer to you.

 

Spoke to a tech friend (top notch Hummer Mechanic)who suggested to start out with the most likely stuff, like changing out the fuel filter,plugs,wires and clean out the Airfilter. I have one of those Ram Inductionair filters which you clean and re-install.. The fuel filter makes alot of sense. Since I have a supercharger with duel fuel pumps the filter is working twice as much. By the way in addition to the supercharger I have also installed theStage IIB kitfrom Breathless Performance which has really made the supercharger sweet. Here's the link to Breathless Performance http://www.breathlessperformance.com...0Stage%202.asp.

After doing all that typical tune up stuff, he saidif I'm still having trouble have the injectors cleaned out.I will keep you all posted. Thanks forall theadvise.

 

Before you start fooling around with the injectors..run a couple of cans of this stuff through (1 can per tank full)...This stuff is phenomenal (pricey too, about $20.00 per can), But it works miracles..Google it to find a distributor near you.
BG 44K

 

Thanks. I heard about this awhile ago froma dealership thathad once worked on my daughter's car which had an EGR problem. It seem to have help. I will give it a shot. How often do you think I could use it?

 

To start with one canper the next two tank fulls..let the tank go almost empty before refilling.

I use it in my Jag and Hummer, one can at every oil change (5000 miles) and RedlineSI-1, one bottle every 1000 miles