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Failed Smog - About to tempt 2nd try at Smog - Few Questions


redstx40

Member
Joined
Aug 8, 2007
Messages
19
City
Bay Area, CA
Vehicle Year
1992
Transmission
Automatic
Hey all,

So to start off here are my test results from the first try:

HC CO
MAX GP MEAS MAX GP MEAS
15mph 86 310 452 .51 2.03 .80
25mph 72 260 542 .65 2.23 .96


The engine also has a slight misfire but the truck drives fine. So far I changed the spark plugs, wires, fuel pressure regulator, PCV Valve, oil. Cleaned MAF as well. When taking out the the spark plugs i noticed all 3 spark plugs on the passenger side had more of a fuel smell (and a little wet looking) and the drivers side had a light white tint to them. So I figure the passenger side of the engine is the problem. I am thinking it may be the ignition coil pack but it is fairly new about 2 years but is a BWD brand I believe or some other brand like it. Perhaps it went bad?

The CEL isn't on and there are no codes, everything is ok.

Anyone have any ideas why the HC is high (I know it means unburnt fuel), and from what I read the CO is related to the HC. Just want to pass smog.

My truck is a 92 ford ranger V6 4.0L with close to 270k!!!

Thanks for any help.
 
injectors may be getting ugly. or dying

try cleaning them.
 
o2 sensor fresh?

converter may simply be beat as well.
 
How old is your cat? Thats where I would be looking for hydrocarbons being too high.
 
Hey,

Thanks for the replies,

Cat is about 4 years old or so. O2 sensor is about 4 years old as well. I ran a few bottles of fuel injector cleaner (Red Line, chevron, other brands).

I'm just curious how the passenger side is running more rich then the driver side. since this truck only has one o2 sensor, it's just reading both banks.

Also just incase there is any confusion, I did all the tune up and other part changes after the first smog try. So I should get better results on the 2nd try. Just dont want to fail again, so I'm trying to take as many reasonable precautions.
 
If its only 4 years old, cat probably isn't the culprit...
from what you described, it sounds like you are getting too much fuel into the cylinder, or not getting good spark, sadly I dont know how to fix either particularly well... Maybe try a new coil pack, and if that doesn't solve anything just return it?

You know to run the truck for a good while before going in to get everything nice and hot and working at max efficiency right?

Oh, wet plugs could also mean water getting into the combustion chamber couldn't it? so maybe a leaky gasket or something on the passenger side?
 
Thanks for the reply,

Wet as in the spark plug has fuel still on it, no signs of coolant. Since the other side of the engine the spark plugs are all dry. There maybe another term but for sure the passenger side shows sign of excess fuel (the culprit most likely in the high HCs).

Since the ignition coil pack has 2 rows of 3s, I was thinking one side isn't capable of producing enough spark causing the passenger side to not fire as well/strong (all 3 spark plugs). Does this logic seem correct or does the ignition coil work another way.

I may have to try another ignition coil.
 
o2 will definitely be an issue if the head gasket is leaking, but i would have to think you would have reported it eating coolant in that case.

i took the wet plug as fuel from the description.

possible that the ground is weak or they dont have full power on that bank.

cylinders 1,2,3, are on pin 58 and 4,5,6, are on pin 59 in a 92.


weak spark or hanging injectors/leaky....

hell i could go on for hours.


make sure you have close to batt voltage on the injectors....
 
Last edited:
Worst case scenario is leaky injectors but i'm hoping to avoid to having to change them out.

Bobby: So you think the ignition coil could be the culprit, if my logic is correct or even somewhat correct about the way the coil works?

Thanks
 
its a type of waste spark system, so there maybe something causing a random inhibit shutting down one side...:dunno:


on the pack you will see the way the pairs are setup...it fires both on those pairs at once.....when it happens one is on compression the other exaust.


if the wires are good, i lean towards some defect in the injection system
 
Last edited:
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