Cylinders 3 and 4 are dead, why? Options

[Skid]

I just brought home a 73 1.7. This is the first 914 that I have actually owned, but not the first one that I have driven. My dad has always had a few 914's around and I finally decided it was time to get one of my own. When I first picked up the car, it ran pretty good and smooth. The original fuel injection has been removed and replaced with some duel single barrel weber carburetors and it has a 009 distributor. Like I said, the car ran pretty good when I first got it about 2 weeks ago. For the past 2 weeks I haven't driven the car more than just around the block, and suddenly, out of the blue, I went to go move the car and it is running bad. It has a definite misfire and, when I pull the plug wires off the distributor cap, 3 and 4 seem not to be firing. I have checked compression in those two cylinders and they are fine. I am getting fuel (I can see that the carb is squirting gas), and I have also tested to see that I was getting spark on those two cylinders. If I have spark, fuel, and compression, what am I missing? How could it just change overnight? I am pretty stumped here, my dad, who has worked on these things for over 20 years is also pretty stumped. Any ideas or help would be very appreciated.

(IMG:http://www.914world.com/bbs2/uploads_offsite/lh5.ggpht.com-3538-1273364830.1.JPG)

(IMG:http://www.914world.com/bbs2/uploads_offsite/lh4.ggpht.com-3538-1273364831.2.JPG)

And the mess of an engine bay..... (IMG:style_emoticons/default/barf.gif)
(IMG:http://www.914world.com/bbs2/uploads_offsite/lh6.ggpht.com-3538-1273364831.3.JPG)

Thanks,
Chase Birks

[Tom]

Check # 3 and # 4 plugs.
Could be fouled as they are both common to one carb.?
Tom

[70_914]

Do you have one of the dual carb tuning tools? Getting fuel does not mean getting the right amount of fuel. The only common part is the carburetor. Check for vac leaks, intake leaks, etc.

Does it smooth out at higher RPM?

[Skid]

I have changed all of the plugs, so I don't think that is the problem. I have also thought that it may be the carb, but I am not sure at this point. I will see if I can tell if they are working correctly. Any other things I should check?

[McMark]

I would rebuild those carbs before I mess with anything else. I would also peek into the gas tank to check for 1/2" of rust flake on the bottom. Then I would check/replace the fuel filter. Then see how it's running.

It was running before, so it's not a compression problem.
It's only affecting two cylinders, so it's not an ignition problem.
It's not air.

So it's a carb problem.

[VaccaRabite]

(IMG:style_emoticons/default/agree.gif)

Lots of little passages that could be plugged in the carb which would cause it to go dead.

Zach

[Katmanken]

My bet is ignition problems.

With a single carb, if two of the cylinders run, it's not the carb.

Did it rain? Is there an engine tray under the grille?

Does the dizzy cap have burned electrodes, a crack or a carbon arc trail? Had a cap once that looked great, ran crappy, and everything checked. New cap and life got better.

With a new car, I'd do a tuneup- points, condenser, plugs, cap and wires.

[McMark]

But it's not a single carb. It's dual carbs.... (IMG:style_emoticons/default/blink.gif)

[Katmanken]

OK, OK, I read duel single barrel and brain stopped there without looking at the picture....

Some VW's that I've seen have used a single carb with dual barrels, and the owners referred to them as dual single barrels...

[JamesM]

Hurry up and get that thing running, you have a PCA autocross to get to this sunday! We need more 914s there.

Let me know if you need a hand... or parts. My house is starting to look like a 914 wrecking yard. (IMG:style_emoticons/default/smile.gif)

[Skid]

Ok! I figured it out! Boy do I feel stupid. I worked on the car for hours on saturday. I changed plug wires, plugs, rebuilt the carb, adjusted the timing, and a few other things, and nothing helped one bit. I was playing with the timing when the car backfired and my dad noticed that flame came out from the manifold on the dead side. He reached down and stuck his finger over the hole, which was just out of view, and just like that, the car sprang back to life and ran just like before. I guess some little plug that had been there before must have fallen out and caused a vacuum leak. So for those of you who guessed vacuum leak, you win the prize! Thanks for your help and info. I am sure I will be needing lots more of it as I get this little guy back on the road. Next step, emission and inspection, wish me luck.

[Skid]

Oh, and James, I will sure try to make it to that autocross. I don't know if it will be ready for that by sunday, but I guess I could bring the 944 if I had to. Its been a few years since I have autocrossed a 914, I can't wait to try it again!

The last autocross that I was at, we brought 3 914's and a 993. I drove the 993. This is my family, from left to right, my little brother, my little sister, my dad, and me.
(IMG:http://www.914world.com/bbs2/uploads_offsite/lh6.ggpht.com-3538-1273510963.1.jpg)

[Root_Werks]

So your Dad got to drive the steel top then? (IMG:style_emoticons/default/driving.gif)

[70_914]

Ok! I figured it out! Boy do I feel stupid. I worked on the car for hours on saturday. I changed plug wires, plugs, rebuilt the carb, adjusted the timing, and a few other things, and nothing helped one bit. I was playing with the timing when the car backfired and my dad noticed that flame came out from the manifold on the dead side. He reached down and stuck his finger over the hole, which was just out of view, and just like that, the car sprang back to life and ran just like before. I guess some little plug that had been there before must have fallen out and caused a vacuum leak. So for those of you who guessed vacuum leak, you win the prize! Thanks for your help and info. I am sure I will be needing lots more of it as I get this little guy back on the road. Next step, emission and inspection, wish me luck.

I guess all that time and money I spent going to school to become an automotive technician paid off... (IMG:style_emoticons/default/smilie_pokal.gif)

Glad you got it running right!

[Skid]

So your Dad got to drive the steel top then? (IMG:style_emoticons/default/driving.gif)

Yeah, and I schooled him (IMG:style_emoticons/default/driving.gif) . But his car wasn't running good, so it wasn't fair. I did like that car, but right after getting it, he sold all of the 914's other than the 993. I am trying to get him back into them now, and with my car, he is getting a little interested again.

[Skid]

Ok! I figured it out! Boy do I feel stupid. I worked on the car for hours on saturday. I changed plug wires, plugs, rebuilt the carb, adjusted the timing, and a few other things, and nothing helped one bit. I was playing with the timing when the car backfired and my dad noticed that flame came out from the manifold on the dead side. He reached down and stuck his finger over the hole, which was just out of view, and just like that, the car sprang back to life and ran just like before. I guess some little plug that had been there before must have fallen out and caused a vacuum leak. So for those of you who guessed vacuum leak, you win the prize! Thanks for your help and info. I am sure I will be needing lots more of it as I get this little guy back on the road. Next step, emission and inspection, wish me luck.

I guess all that time and money I spent going to school to become an automotive technician paid off... (IMG:style_emoticons/default/smilie_pokal.gif)

Glad you got it running right!

Yeah, I guess, that would help. Thanks again.

[Skid]

Ok, so I lied apparently. 3 and 4 are now running nicely, but numbers 1 and 2 are struggling now. 1 appears to be pretty much dead and 2 is definitely not running as good as it should. I have gone through both carbs and think that both are working good. I have looked and can't find any other vacuum leaks and I just have no idea how this problem migrated across the motor as soon as I had the other two fixed. Any more ideas?

[JamesM]

Yup, i recognize those cars! I was wondering why i have not seen you guys out there since then. I thought i saw them up for sale a while ago though, did your dad get rid of them? They were pretty clean cars from what i rememebr.

Oh, and James, I will sure try to make it to that autocross. I don't know if it will be ready for that by sunday, but I guess I could bring the 944 if I had to. Its been a few years since I have autocrossed a 914, I can't wait to try it again!

The last autocross that I was at, we brought 3 914's and a 993. I drove the 993. This is my family, from left to right, my little brother, my little sister, my dad, and me.
(IMG:http://www.914world.com/bbs2/uploads_offsite/lh6.ggpht.com-3538-1273510963.1.jpg)

[JamesM]

So your Dad got to drive the steel top then? (IMG:style_emoticons/default/driving.gif)

Yeah, and I schooled him (IMG:style_emoticons/default/driving.gif) . But his car wasn't running good, so it wasn't fair. I did like that car, but right after getting it, he sold all of the 914's other than the 993. I am trying to get him back into them now, and with my car, he is getting a little interested again.

Your dads was a 6 too from what i remember. I was thinking with a little work that could have been one of the fastest, if not the fastest car we have out there. Sucks he got rid of them.

Let me know if you cant get those dual carbs figured. I have a couple progressive setups sitting around if you want to try one out. Not an ideal setup by any means but it might be a quick fix for now to get you on the road.