THE PORTAL HUB - Pinzgauers, Haflingers, Volvo 303s and more!

I can't seem to get the #1 cylinder to fire.

I have replaced the civi cap and rotor, set the timing, changed the plugs, even adjusted the valves.

The truck idles just fine but as soon as I put a load on it has much less power than it should. I can only make about 80KMH max. The valve cover for #1 never really gets as hot as the other three making me think this is the culprit.


Any thoughts?

have you run a compression check on it? What does the plug look like?

you are going to have to isolate the cause of the problem, air,fuel,and spark are what is needed for combustion. Its obvious you have those otherwise the Pinz would not run at all and you stated you have it running at 80kph...I would first check for a strong spark to cylinder#1..if you have a good blue spark go to a compression check and a cylinder leakdown if compression looks good. Did this problem just occur? did it happen after a offroad trip? after fording a river? most of the time when something happens immediately after an event like previously mentioned it is electrical in nature and not mechanical.

I haven't done a compression check yes. The plug looked a little dark, maybe a little oily but not bad. Definitely not the nice gray of the other three. I need to check the wire/spark but it seems OK visually. ie no obvious cracks or worn spots on the insulation and the connections all seem good. I hope to put an Ohm meter on the wire after work today.

I believe it is electrical myself. This truck seems to have huge problems getting water in the dist cap. I have sealed it everywhere I know to, and in a driving rain it will always get wet!! I never had this kind of problem with my 710 in the same weather.

Thanks

Ohm meter will test for wire reisitance and continuity, but I would be far more interested in sticking a screwdriver into the plug end of the wire and holding it close to a ground while cranking to see whether you are getting a good strong spark..unless you have test instuments to measure coil output. Do not assume because something is new or looks good...that it is...many parts are defective right out of the box..we had such an instance recently where one of the guys in my shop had a truck running badly after a tuneup..it ran fine before the tuneup...after some head scratching we closely inspected all parts and found the distributor cap terminal that was partially covered with a piece of plastic from the molding process causing that plug not to fire. Lesson learned start with the basics and go from there.

Sounds like a cracked/worn plug wire to me. You can try swapping #1 with #2 and see if the problem swaps. I've also used a spray bottle in a dark garage. Spray the wires down and look for arcs.

I may or may not recommend the compression check. Sometimes its best to not know your compression and think the best. Aids in sleeping at night

I have to agree that I am not anxious to check compression!!

I have already made up a new set of plug wires and will probably try a new one on #1 and see what happens. it was suggested to try the Ohm meter and the spark.

I like the spray bottle idea!!

Sometimes ignorance..is bliss...but just postpones the inevitable!

When was the last time you checked your valves? Also cylinder one seems to run cooler in general can you give temp diff between them? Also timing.

I changed out the #1 plug wire without any improvement. I guess I will make up three more and see if that helps.

Running out of things to fix/change!!


Erik check my first post.

Here is a guess. It may be the coil again. Several posts on what t look for with coil voltage.

Pulled the Distributor out today and tore it down/cleaned it up. No cHange.

Just to be clear on details:

You've got a civvy ignition set-up, and you've still got no spark on the #1 plug?

You've already replaced the cap & rotor (I assume because of this lack of spark on #1 ?).

All correct?

Can you take a known good plug wire, and a known good plug, and (by grounding the plug) get the #1 plug to spark? (perhaps you had a bad plug or wire, and replaced it with a new bad part.)

If you've got spark on 3 plugs, but no spark on just one, it seems unlikely to be a bad coil. I'd think the problem would be evident on all 4 plugs (poor burn, bad color, etc.).

If you've got a decent spark on #1, it might pay to re-check your valve adjustment on that cylinder. (Maybe you made a mistake on it the first time?)

What is the #1 plug's spark like?

Actually the only thing that makes me think #1 isn't firing is that the valve cover is not as hot as the other three. The truck will idle fine but will not get up to speed well and will only get up to about 55 MPH. It won't climb a hill and keep speed. In general it has no power.

I do have an exhaust leak at the manifold but I don't see how that could be contributing to this much loss of power. This truck has run 65 with 1900 pounds of steel in the back before.

Pinzgauer Pete wrote:Sometimes ignorance..is bliss...but just postpones the inevitable!

:idea: Check compression

Ed