After day 1 of my 30 day trip through the Icelandic highlands, my 2004 H2 is showing some worrying signs...
After a brisk sprint, on our way to the mountains, not there yet nota bene, the troubling CHECK ENGINE light started blinking. This happened after accelerating from 30 - 80 mph, with my foot down.

After slowing down, the light steadied into a continous light, much more pleasing to the eye, but not to the nerves.
My initial thoughts while driving, were that this had something to do with the broken gas cap, the thingy that makes the ratchety sound when closing doesn't click, so i guessed the cap wasn't properly closed and everything is dandy.

Went to a small garage, who have a GM read out computer,to make sure the code wasn't serious, and it diagnosed the cylinders 2 and 7, are continuously misfiring, i watched the misfiring counter and it looked like clockwork.

So now the question is:
Is it a clogged injector(s)? - argument suggesting this is that there is -no- gasoline smell from the exhaust.

Is it simply a broken spark-plug (s) This is the -default- diagnosis and it would probably make sense to replace no. 2 and 7 just for the heck of it.

Bigges question of all, is it safe to drive on, for 3 more days, until i reach civilisation again, or will driving the engine with 2 cyl's misfiring cause damage to it?

bonus questions:
How do i replace an injector, and a more trivial one, how to i pull the cable from the spark plug, just jank it off? :S

Cheers, from the root of mount Hekla, (previously known as the gate to hell)

 

I asked my husband about this and he said that if you have a miss on 2&7 that your h2 would be running rough, lack power, and be getting even worse gas mileage than normal, but it wouldn't hurt the engine if that is the problem. Also, that it would be unlikely that 2 injectors, plugs, or coils would go bad at the same time. He thinks that the shop had the computer on the wrong setting and that it was an intermittent problem caused by hard acceleration if these symptoms are not present now. One more thing, did the shop reset your trouble on your engine's computer ( is the check engine light still on).

PS: Don't pull the plug wires off while it's running and gruond them before you start the h2.

 

If your check engine light is flashing you risk doing damage to the Catalytic convertors. If it is on solid you should be fine to drive it. I would replace the spark plugs at least on those two cylinders. The plug wires are tight so make sure to twist the boots before you pull them off. Some injector cleaner in the fuel tank might be a good idea. You could also have an intake leaking but under hard acceleration it wont have that kind of effect, so I would lean more towards the plugs, plug wires or Injectors. You could swap plug wires from another cylinder and see if the misfire counter shows the miss on a different cylinder now. Good luck from Kansas.

 

Thanks Humher, and Calif Phil for your help :-)
I found a traktor workshop that allowed me to use their tools, and helped me replace the plugs, all 8 were worn, but not too bad. I exchanged all, but did not replace cables. No change noted in engine running, but now i'm at least sure that it's the plugs. (or plug controls)
We then continued our trip, through Arnarvatnsheiði, over a high plateo through some lava fields and sand/rock deserts.
Engine did it's job, albeit hesitantly, and more thirsty than i had expected, 33 liters over the first 64 km, a bit better after that. That's about 5 liters per hour, not bad in boat terms :-) Biggest challenge turned out to be the wider tire track, at times we would rub badly against the surrounding rocks, damaging the tires somewhat. And ground clearance is an issue, i knew the H2 has IFS but not that it would slam into each and every pebble on our way :S, i guess a lift is in neccessary to take it anywhere serious.
We made a brief detour to Eiríksjökull, just west of Langjökull, and promptly got stuck on the first 2 meters, but were pulled out by two passing landcruisers, on 40" tires on 15" rims, which is pretty much the standard here in iceland for Trucks intended to drive on snow. The H2 is a heavy beast, but only 300 kg heviear than my previous Nissan Patrol, which on 35" tires, 15" rims, would at least make an effort in snow, not just play dead like the grand lobster, king crab, i'm still working on a name for the H2 ;-)
Overall we made it through the first passageof our trip in one piece, and all in high spirit.

Next thing to do is to fix those plugs. I have spoken to a mechanic in Akureyri, who has done work on the H1's and some plug work on other US trucks, but does not have ultrasonic cleaning tools usually used to restore injection plugs, but he thinks it might be possible to clean them manually.
Option 2 would be to make a 500km detour back south and have the plugs cleaned at generic tuning shop, who claim to restore injection plugs routinely (my fear here is that they will just conclude that i need new plugs, and they'll have to order, 3 weeks wait usually.
Option 3 is to just keep pouring injection cleaner into the tank and just accept the poor milage and hope for the best.

After reading some on the chevy forums, we have gsm coverage in even the mose remote locations here on the island, i see that the chevy guys just rip out those plugs from their vortec engines and rinse them in bourbon (or was it brake cleaner), routinely, i might just be stupid enough to try that myself, when we are back home. I'll order some new plugs on ebay, just to be on the safe side.

Has anyone here experiance with that, taking off the injection rails and replace the plugs, the process seems quithe simple to me, accepting that i will have to sit -in- the engine bay to reach anything in there ;-)

Another question, while i have internet access, what would be the cheapest way to lift the H2, around 4" would probably do, i'm just interested in clearance and being able to run 37" tires, any recomendations, preferably cheap and easy to ship around the globe :-D

Cheers, from the Húnaflói, ("Polarbear bay") from the V6 King Crab and crew

 

Well finally bit the bullet today, and cleaned up injector nr 7, after doing some reading on the internet, on the cellphone.
a)I de-pressurised the fuel pump, by pulling the fuel pump relay, and starting for a few times.
b)Disconnected the Fuelrail holding clip, and the electrical connector on the injector.
c)Loosened up the two bolts holding the fuel rail
d)Pulled the rail just high enough so that i could wiggle the injector out of both the manifold and the fuel rail.
e) The injector was full to the top with rust flakes and dirt and gunk. Knocked outthe worst, then scraped witha broad needle and then wiggled in stp injector cleaner for 10 min's, until it looked shiny and new

f) lubed the orings with some oil from the oil dip stick, and popped it bak in there

g) after a harsh but short panic moment of not realiziing i had'nt put back the fuel pump relay back, the H2 started up with a perfect purr, or perhaps it's more like a regular gnarl, anyhow, it runs really well now, more sophisticated method's will have to wait until we are back in civilisation.

Thank you guys for your help again, it really gave us the courage to go along, and then the spirit to attackit

Cheerio.

 

You should post some pics of your trip...would love to see some