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1997 Honda Passport (Rodeo) 3.2 V6 - #5 cylinder misfire

3K views 7 replies 4 participants last post by  chongkan 
#1 · (Edited by Moderator)
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Well, my 97 Passport (same as ol V6 3.2L Rodeo) is sick, and I need some help diagnosing what the problem could be. The Check Engine light is flashing, and I'm getting the P305 #5 cylinder misfire code. It's also running/idling rough, and has the expected loss of power (& gas mileage). Some background:

- I've had issues with it continuously throwing codes for EGR insufficient flow, even though I've replaced the EGR valve with a new one. There does seem to be black soot coming from the tailpipe, which may be a symptom of this problem.

- In Jan of this year, I replaced all 6 spark plugs and air filters as part of its routine maintenance. The O'Reilly's store recommended Bosch double iridium plugs, which is what I went with. No problems were noticed.

- Last weekend on the way from Virginia to Ohio, the Check Engine light started flashing and the car started running a little rough. When I got to my destination, I pulled the #5 spark plug and the side electrode (the bendable part) was missing! I went to the local O'Reilly's store and purchased a new Bosch double platinum and installed it. I had to drive the car back to Virginia, and unfortunately the #5 misfire came back again along with the rough running.

Back here at home, I've done some things:

- I've pulled the spark plug, and looked at it's condition (the new one). Attached is a pic of it.
- I've checked for ignition by hooking up an inline clear spark light, and it lit up like a x-mas tree. So it seems to be getting good spark.
- I've done a compression test, and the 3 readings of 120, 95 and 118 seem to be a little low, but still not bad.

Thoughts? Fuel or spark plug issue?
 

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#2 ·
do a leak-down test on the low cylinder. find out where the compression is going- past the valves , or rings...
maybe the #5 injector is overfueling/ leaking...washing down the cylinder, lowering compression.

i had #5 injector fail on a 5.4 ford 3 valve....loaded the cylinder with fuel, bent the connecting rod....
 
#3 ·
EGR valve: you also have to clean the EGR TUBE because the tubes get full of carbon. This will cause a low / no flow too. Dennis
 
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#4 ·
Thanks for the reply. Understand about the metal tube getting clogged with carbon - that's something I'm going to have to remove and clean. How difficult is that?

For the #5 cylinder, is there an easy way I can determine if the fuel injector is even firing, or even working correctly?
 
#5 ·
Should be a hold down bolt on the exhaust manifold and a gland nut on the intake end. Maybe a bracket / bolt somewhere in between. From the looks of that plug, you have an injector dumping fuel in the cylinder. Don't remember how accessible those injectors are, but if you can get to it, try unplugging that one and see if there is any difference in the running. Dennis
 
#6 ·
Thanks - looks like to even get to the fuel injector harness, and the fuel injectors themselves, I'll have to remove the upper intake plenum.

Hmmm well the plug may be covered in a slight coat of oil too - I've noticed some slight oil on the plugs the last time I did a tune up.
 
#8 ·
Thanks - looks like to even get to the fuel injector harness, and the fuel injectors themselves, I'll have to remove the upper intake plenum.

Hmmm well the plug may be covered in a slight coat of oil too - I've noticed some slight oil on the plugs the last time I did a tune-up.
You may just remove the throttle body and inspect the intake manifold with a flashlight. The metal pipe that comes down from the EGR ends about half way inside the plenum. You can then add carb cleaner in the passage from the EGR valve intake and even use a vacuum or blower to clean up that passage.

Q: When you replaced the plugs, were you aware that the coil for #6 cylinder is a bit smaller than all the other 5 coils?

I have been troubleshooting my new LSE 3.2 2001 for a few months now and I had sooty sparkplugs and a misfire in cylinder #4 that later moved to more cillinders. The coils were not in the correct position and after changing that, the misfire got corrected, and the fuel trim levels as well. ( coil for 6 was in the 4 position )

97 is ODBII, you may check the port below the dash to confirm.
 
#7 ·
1997 is obd 2... then can you find a scan tool that goes deep into the ecm and do a cylinder balance test, as well as a injector balance test? turn off the spark to each cylinder and see what happens? not sure on the tech for a 1997 and what the ecm supports....
 
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