1998 Villager Missing

[MojoMan317717]

Need help isolating the problem. Have swapped plugs and wires and the issue does not follow the plug or the wire. There is definitely spark to the missing cylinder. Cap and rotor have been inspected, as well as optical sensor. No dust or crud on the sensor or silver colored discs (have no idea what the technical term for those is). The studs inside the cap are definitely corroded, but the stud going to the cylinder with the misfire is no worse than the rest of them. I cleaned them up a bit with some sandpaper and a wire brush. The injectors are all clicking as they should and I know there is fuel going to the cylinder, because if I run it long enough the header gets glowing red hot, which obviously indicates there is unburned fuel getting into the exhaust and burning there.

Here's my question, is it possible for the spark to that cylinder to be "weak"? I know there is definitely a consistent spark. Could this be as simple as a new distributor cap. Sorry for being too cheap to just try it an see, but money is really tight for me at this time. I need a higher level of confidence before blowing the $$.

Thoughts anyone??

[tempfixit]

Originally Posted by MojoMan317717

Need help isolating the problem. Have swapped plugs and wires and the issue does not follow the plug or the wire. There is definitely spark to the missing cylinder. Cap and rotor have been inspected, as well as optical sensor. No dust or crud on the sensor or silver colored discs (have no idea what the technical term for those is). The studs inside the cap are definitely corroded, but the stud going to the cylinder with the misfire is no worse than the rest of them. I cleaned them up a bit with some sandpaper and a wire brush. The injectors are all clicking as they should and I know there is fuel going to the cylinder, because if I run it long enough the header gets glowing red hot, which obviously indicates there is unburned fuel getting into the exhaust and burning there.

Here's my question, is it possible for the spark to that cylinder to be "weak"? I know there is definitely a consistent spark. Could this be as simple as a new distributor cap. Sorry for being too cheap to just try it an see, but money is really tight for me at this time. I need a higher level of confidence before blowing the $$.

Thoughts anyone??

Which clyinder is missing?? Have you done a compression test? Have you tested the wires???

I would switch injector with another on that clyinder to see if miss follows the injector. Did you have the spark plug out of clyinder and connected to plug wire and grounded to see if spark was blue?? I am thinking that injector is flooding the clyinder causing spark plug to foul.

How many miles on vehicle??

Sending PM

[MojoMan317717]

I know which cylinder is missing, but I cannot give you the technical #. It's in the back farthest left as you face the front of the vehicle.

Have not done a compression test, but seriously doubt that is the issue.

The injector sounds fine, and the gas burning in the exhaust seems to indicate fuel is definitely getting to the cylinder, and then not burning because a lack of or weak spark.

I have inspected the plug and there are no signs of fouling. I did not have the plug out and grounded when I tested for spark. I merely removed the wire and stuck a heavy wire in it and put that close to the manifold. There was a consistent spark. Can it be weak?

185K miles on the vehicle.

Is it difficult to switch an injector? Do I need to remove the manifold and fuel rail to do that?

[tempfixit]

Originally Posted by MojoMan317717

I know which cylinder is missing, but I cannot give you the technical #. It's in the back farthest left as you face the front of the vehicle.

Have not done a compression test, but seriously doubt that is the issue.

The injector sounds fine, and the gas burning in the exhaust seems to indicate fuel is definitely getting to the cylinder, and then not burning because a lack of or weak spark.

I have inspected the plug and there are no signs of fouling. I did not have the plug out and grounded when I tested for spark. I merely removed the wire and stuck a heavy wire in it and put that close to the manifold. There was a consistent spark. Can it be weak?

185K miles on the vehicle.

Is it difficult to switch an injector? Do I need to remove the manifold and fuel rail to do that?

I would remove the spark plug and hook to wire, ground and crank engine to see what the spark looks like on the plug. (What brand plugs are in it)
Yes spark could be weak. Did spark plug look wet when removed?

Not sure but I believe you need to remove the upper plenium to get to back bank to remove the injector. (I will look at manual)

When you looked at the optical sensor did you by chance blow it off with compressed air since you at it exposed??

If I understand correctly, you are faccing the wwidsheld and is theback left clyinder, that would be # 1 clyinder.

If you listened to the injector I would think you should be able to remove and switch with one from front bank.

Did you get my PM?

EDIT: I just looked at my 94 and you may be able to remove injector without removing upper plenium but I did not have a light to see for sure. I could feel the injector under the plenium for the first clyinder on the back bank left side. Injectors should come out seperatley.

[MojoMan317717]

Yes, thanks for the PM. I posted the issue over there as well.

When I pulled the plug it was bone dry, and there was no smell of unburnt gas. The plug had very normal wear. I think they are just cheap autolites.

I will try your method of testing for spark and get back with the results tomorrow.

[tempfixit]

Originally Posted by MojoMan317717

Yes, thanks for the PM. I posted the issue over there as well.

When I pulled the plug it was bone dry, and there was no smell of unburnt gas. The plug had very normal wear. I think they are just cheap autolites.

I will try your method of testing for spark and get back with the results tomorrow.

Have you been able to resolve the problem????

[MojoMan317717]

Sorry for the delayed response. I am borrowing a compression tester from a friend this weekend. I will report back the results. One way or another I won't leave this thread hanging :~)

[MojoMan317717]

I have verified that it is NOT a compression issue. I'm leaning toward a bad injector. How would I verify that?

Am going to change plugs, wires, and cap & rotor later today. Will post results. Sorry for the time gaps, but I work on it when I can, and when money is available, ya know.

[tempfixit]

Originally Posted by MojoMan317717

I have verified that it is NOT a compression issue. I'm leaning toward a bad injector. How would I verify that?

Am going to change plugs, wires, and cap & rotor later today. Will post results. Sorry for the time gaps, but I work on it when I can, and when money is available, ya know.

Yep know the story.

Here is a video on testing of a injector:

http://realfixesrealfast.com/realfix...agnostics.html

http://realfixesrealfast.com/realfix...ges/P0304.html

http://realfixesrealfast.com/realfix...a_plenium.html

The second link is actually of a villager.


Do you have a fuel pressure tester, noid light, volt meter If you have a long screwdriver place it on the injector in question while engine running and listen for the injector clicking which means the injector is getting command from pcm to squirt the fuel. (Listen to a known good injector and compare.)


Hope this helps

[MojoMan317717]

Great video links!!!

I replaced cap & rotor, plugs and wires, but the miss continues. Using a stethoscope I can hear the suspect injector clicking like all the others.

I will measure the injector with my multimeter and post back soon.

[tempfixit]

Originally Posted by MojoMan317717

Great video links!!!

I replaced cap & rotor, plugs and wires, but the miss continues. Using a stethoscope I can hear the suspect injector clicking like all the others.

I will measure the injector with my multimeter and post back soon.

If you need a fuel pressure tester to check if it is squirting fuel like in the videos try your local autozne or oreilys, they should have a testrer in their rent a tool program. Just paay deposit and return within 38 hrs and get your money back. To hook the fuel prewssure tester you need to connect it between the fuel filter and fuel rail, does not have a schraeder valve.

[MojoMan317717]

It is a bad injector. I tested it with my multimeter and it definitely has an open circuit.

Mystery solved. Thanks for the help everyone! I'm off to the salvage yard tomorrow to get a new injector.

Unfortunately it looks like a massive project to remove the entire upper intake manifold and many other peripherals just to get at the stupid thing. It's a good thing I have more time than money

[tempfixit]

Originally Posted by MojoMan317717

It is a bad injector. I tested it with my multimeter and it definitely has an open circuit.

Mystery solved. Thanks for the help everyone! I'm off to the salvage yard tomorrow to get a new injector.

Unfortunately it looks like a massive project to remove the entire upper intake manifold and many other peripherals just to get at the stupid thing. It's a good thing I have more time than money

If you are going to salvage yard why not investigate for any short cuts to removing upper plenium.

[MojoMan317717]

It was the injector (obviously). Fortunately I was able to get to it with relative ease and did not need to remove the upper intake manifold and the many things attached to it!! Found a used one at a salvage yard that overnighted it to me for $35 total (including the shipping)! What a bargain. I could have purchased 2 and still spent less than buying a new one.

A huge thank you to all those who chimed in here to help me! This forum is always my first stop when looking for answers.

[tempfixit]

Originally Posted by MojoMan317717

It was the injector (obviously). Fortunately I was able to get to it with relative ease and did not need to remove the upper intake manifold and the many things attached to it!! Found a used one at a salvage yard that overnighted it to me for $35 total (including the shipping)! What a bargain. I could have purchased 2 and still spent less than buying a new one.

A huge thank you to all those who chimed in here to help me! This forum is always my first stop when looking for answers.

Glad you got it fixed and thanks for posting fix.