DodgeIntrepid.Net Forums banner

1 - 15 of 15 Posts

·
Registered
Joined
·
46 Posts
Discussion Starter #1
Hi,
Just recently my '96 3.5L started misfiring while driving. It doesn't do it all the time, just occassionally. I notice it most often when I am accellerating (going downhill or coasting it doesn't appear to miss). I also notice it when the car is sitting still and in drive. If it is in park it runs fine. At first I thought it was bad gas (just filled up) but I put some dry gas in the tank and that hasn't cleared it up, plus the fact that it runs fine while in park sorta kills that theory.

It currently is not showing any codes (just 55, which is the end of the code listing).

Can anyone shed some light onto what is causing this? I'd like ti get it fixed before it (possibly) develops into something more.

Thanks,
HP
 

·
Registered
Joined
·
3,041 Posts
Check out your PCV Valve and the Tube that leads up to it, if it has any cracks in it get it replaced, also clean out your Throttle Body and the IAC too. And check your plugs out, make sure the gap is correct. If the plugs are old get them replace along with the wires.
 

·
Registered
Joined
·
253 Posts
This happened to me too. It was a corroded connector on the end of a sparkplug wire at the connection to the coil. Moisture had gotten in and the connection was open.

Later, I discovered that you must use a lot of silicone at that connection to make it difficult for water to get in.

I'll bet you just need to replace the wires.
 

·
Registered
Joined
·
46 Posts
Discussion Starter #5
Sector001 said:
How many miles are on it? I had an old Chrysler that did the same thing before the fuel pump went...
It's got 144,000 miles on it. Can't remember if the fuel pump or filter were ever changed before.

Thanks
 

·
Registered
Joined
·
46 Posts
Discussion Starter #6
Strongt said:
Check out your PCV Valve and the Tube that leads up to it, if it has any cracks in it get it replaced, also clean out your Throttle Body and the IAC too. And check your plugs out, make sure the gap is correct. If the plugs are old get them replace along with the wires.
Strongt: I'll check the PCV valve and hose. I remember replacing the hose about 2 years ago because it was all deteriorated. I cleaned the IAC at the same time as well. I'll give that a cleaning also.


vision67 said:
This happened to me too. It was a corroded connector on the end of a sparkplug wire at the connection to the coil. Moisture had gotten in and the connection was open.

Later, I discovered that you must use a lot of silicone at that connection to make it difficult for water to get in.

I'll bet you just need to replace the wires.
Vision67: The last time i changed the wires and plugs was about 26,000 miles ago. How long are they normally "good" for?
 

·
Registered
Joined
·
3,041 Posts
If you don't know how many miles that are one your fuel filter, I would get it changed, it easy to do, I posted instructions awhile back on how, but if you need it I'll post them again. Also pull your plug and see how they look like, check the gap. But I would change them and the wire's just for the peace of mind. Just pick up a set of Champion Cooper's they seem to be the best for our engines. And vision67's right to check those coil connections.
 

·
Registered
Joined
·
7 Posts
Good luck, If you find out what the problem is let me know. I have the same issue a 96y with a 3.5 and 145000 miles. The best advice I can give is junk the p.o.s. The dealer and has no idea.
 

·
Registered
Joined
·
253 Posts
hp550c said:
Vision67: The last time i changed the wires and plugs was about 26,000 miles ago. How long are they normally "good" for?
They can easily fail again at 26K miles if you didn't use silicone grease at the interface when you did it the last time. That's why mine failed to quickly. :crying:
 

·
Registered
Joined
·
46 Posts
Discussion Starter #10
vision67 said:
They can easily fail again at 26K miles if you didn't use silicone grease at the interface when you did it the last time. That's why mine failed to quickly. :crying:
OK, I will replace the plugs and wires when I get back to my parents house next (Dad has the tools). When you say put some silicone on the 'interface', what are you referring to? The connectors at the coil?

Also, I'm a little stumped as to why it would only mis during accelleration and not while sitting in park? You'd think if it was a plug or wire that it would do it during all conditions. Wouldn't you?

Thanks,
HP
 

·
Registered
Joined
·
253 Posts
hp550c said:
OK, I will replace the plugs and wires when I get back to my parents house next (Dad has the tools). When you say put some silicone on the 'interface', what are you referring to? The connectors at the coil?

Also, I'm a little stumped as to why it would only mis during accelleration and not while sitting in park? You'd think if it was a plug or wire that it would do it during all conditions. Wouldn't you?

Thanks,
HP
Grease the inside of the connector(s) on the end of the wire (both ends) so the silicone grease can displace any room for condensation.

As for missing only under load, perhaps a weak spark is OK at idle, but inadequate under load.
 

·
Registered
Joined
·
46 Posts
Discussion Starter #12
vision67 said:
Grease the inside of the connector(s) on the end of the wire (both ends) so the silicone grease can displace any room for condensation.

As for missing only under load, perhaps a weak spark is OK at idle, but inadequate under load.
OK, will 'dielectric grease' work for this? Or what type of grease should I use?

Weak spark makes sense to me, just hope this is it :)

-- HP
 

·
Registered
Joined
·
253 Posts
hp550c said:
OK, will 'dielectric grease' work for this? Or what type of grease should I use?

Weak spark makes sense to me, just hope this is it :)

-- HP
Try this: DIELECTRIC TUNE-UP GREASE, 3 OZ. TUBE

Manufacturer: PERMATEX
Part # PTX-22058
LIST PRICE : $13.49

YOUR PRICE : $8.99

Buy it at any Auto Parts Store, e.g. NAPA, Autozone, Advance Auto.



As for a weak spark, imagine you have a circuit with 2 resistors in series

-----/\/\/\/\----/\/\/\/\----

--------R1---------R2------

R1 is caused by the air gap in the bad connection, and R2 is the spark plug. Voltage dropped across R1 is wasted, less voltage is dropped across R2, so you get a weak spark.

New wires and a good connection protected by silicone grease will reduce R 1 to zero, so you get full voltage dropped actoss R2.
 

·
Registered
Joined
·
46 Posts
Discussion Starter #14
Just wanted to put a close to this thread. I replaced the spark plugs and spark plug wires and my miss went away :)

Thanks for all the information and help guys!

-- HP
 
1 - 15 of 15 Posts
Top