Lost a cylinder, Car is missing bad Options

[catsltd]

Been working steadly on fixing my 1974 1.8L.
New injectors,plugs,Petronic point replacemnt.etc.

Driving to the store when all of a sudden something happened.
Car felt like it had dropped 1 of the cylinders.

Car does not rev at all,made it home and parked it.

Diid a compression test (cold),110 110 100 90.

Not happy with 90 on cylinder 1 but felt at least like motor should still be running.

Where do I go next.????

I have a dual vacuum line throttle body,and a single vacum on my for sure non stock distributor that had a 4500 RPm rev limiter.

(Distribitor mark for cylinder 1 is 180 degrees out.)

Like I said I put on a pertronic 1847 and a petronic blaster coil and 8MM wires.

I am thinking its a spark think,but really dont know what to do at this point.

I have ordered a Mallory Unilite distribitor(4554101),but wont install it till I figure this out.


Hoping for some help from you guys.
Thanks Grant.

[catsltd]

So my questions are.

1.Is the compression Okay,or did something happen???.
2.What can I do next.
Thanks very much for your help.

[snakemain]

I had something similar happen on mine years and years ago. Dropped the engine and took a bunch of stuff apart, changed some stuff, and put it all back together and it ran fine. Still wonder to this day if I had a badly loose spark plug/plug wire and just missed it when troubleshooting.

[Spoke]

I don't think those compression numbers are that bad. Shouldn't cause one of the cylinders to not fire.

Which cylinder is it? Is it the one with the low compression?

Check wires and plugs. Shouldn't be the Pertronix if the other cylinders are firing.

[r_towle]

Do you have spark?
Do you have fuel via the injector at the right time?

[catsltd]

I don't think those compression numbers are that bad. Shouldn't cause one of the cylinders to not fire.

Which cylinder is it? Is it the one with the low compression?

Check wires and plugs. Shouldn't be the Pertronix if the other cylinders are firing.

I am not sure which cylinder is not firing.
There was one spark plug that was slightly wet but the compression is 110.

Really just trying to figure out what to do next.

The spark plug wires are brand new,but 1 fell apart while pulling it out,so Ill try and fix it.
I ordered new plug wires just to eliminate the possibility they are bad.

I will try and test tonight and see which cylinder is not firing.
When turning over cylinder 1 it makes a weird noise and it is the lower compression cylinder.

With the distiritor 180 degrees out,I am not that confident with the timing I set it at.

I am also concerned they adjusted my valves when they did the timing,car does not catch well when turning over.

Ill start with plug wires and see where that tales me.

I will have to try and check my timing as well,not having much luck finding TDC though.

Thanks for your help.

[Valy]

What do you mean by dizzy 180 over?
Did you check it with a timing light? Don't look at the angle of the dizzy, all that's important to see is if cylinder 1 lights the light in the right spot. What ignition angle you get at 3500 RPM without vacuumatic advance?

[Dtjaden]

The way I would approach troubleshooting:

1. Pull plug wires one at a time. Does the engine rpm decrease or does it stumble when one particular plug wire is pulled? If so that cylinder should be good. If you find that pulling the plug wire on one cylinder does not hav an affect that is the cylinder that most likely has a problem.

2. You can also do this cylinder by cylinder testing by pulling the connector on each injector, one by one. If you find one cylinder where pulling the connector does not cause any change in the engine as above you can do one further test. Pull the injector and carefully place it in a jar to see if the injector is working (careful, gas is flammable). If it's not working you could have a bad injector, injector wiring or computer problem.

3. One last thing I might check is replacing the rev limiting distributor rotor with a fixed rotor to eliminate that as the possible problem.

Finally there is a troubleshooting thread on The Samba:

http://www.thesamba.com/vw/forum/viewtopic.php?t=482560

Good luck,

Darryl

[Dave_Darling]

First, find out which cylinder is dead.

Next, see what is wrong with it. You need three things to fire: Fuel, air, and spark. The compression check is a reasonable proxy for checking the air. (Your numbers sound on the low side, but lots of things can affect that, many of which don't reflect on the health of the engine.)

It might be worth pulling the valve cover off that side of the engine and looking at what happens to the valves. When they close, is one of them further down toward the head than the rest? If so, and especially if that's the problem cylinder, suspect a dropped valve seat.

So check the spark by hooking up an extra plug to that plug wire and taping it to ground. Crank the starter and look at the plug, you should be able to see a nice white spark.

If you have spark, check the fuel. You can remove the injector from the intake runner pipe and stick it in a jar. Crank the starter and watch the jar--does it get fuel? Or you can pull both injectors off that side and put them both in jars; that way you can compare the spray pattern and the amount coming from each.

If all of the above checks out, see if the car runs OK again. If not, then the main suspect would be amount of fuel going in.

--DD

[Series9]

I have found an infrared thermometer to be extremely useful in diagnosing both dead cylinders and fuel ratio problems.

Start then engine and aim the laser pointer at the header near the exhaust port.

You can deduce a lot in a short time.

[catsltd]

Thanks to everyone.

It was a spark plug wire,maybe even 2.
One wire pulled right apart,the other one you could see the metal showing on the top of the boot.

Brand new wires,but pulled them apart to many times I guess.

[Spoke]

I have found an infrared thermometer to be extremely useful in diagnosing both dead cylinders and fuel ratio problems.

Start then engine and aim the laser pointer at the header near the exhaust port.

You can deduce a lot in a short time.

(IMG:style_emoticons/default/agree.gif)


Good to hear you found the issue.

[catsltd]

The spark plug wires were a problem,but 5 minutes later the miss had returned.

But this is the real problem.

The injector plug didnt look right,so I cut it and took a look.
Its pretty easy to see what happens every time I plug it into my injector.

If it was not for the suggestions I received,especially pulling a plug and seeing if it changes the way it runs.
I dont think I would have ever found it.
I am waiting for my new injector plugs.
If the cord is held straight the connector looks normal,but as soon as you push on it or bend it,she disappears.

[Spoke]

Good find.

Looks like the contact pushed back into the plug. You may be able to push it back in and hopefully it clicks into place.

Conversely while you're waiting for a new connector, when you re-insert this connector, get something sharp and small like a mini-screwdriver to secure the contact while you install the connector. At least you'd be able to drive your car until the new parts arrive.