1971 02’ timing/ignition issue question

[Rich S]

Motor running rough and won’t idle. Feels like it’s running on three cylinders. 

work done so far:

-new Weber 32/36 carb.

-adjusted valves at #1 tdc going by marker on timing chain pulley and lining up with oil bar.

-new plugs

-new ignition coil

-set distributor to slightly behind #1 cylinder when at tdc going off of marker on timing chain pulley and oil bar. 
 

I took some voltage readings with the key in the on position and motor not running. It is a non points electronic ignition setup. 
 

any thoughts are welcome!

Thanks,

Rich 

['76mintgrün'02]

8 minutes ago, Rich S said:

-adjusted valves at #1 tdc going by marker on timing chain pulley and lining up with oil bar.

 

This part is confusing.  Did  you set them all while #1 was at TDC?

 

Have you seen the valve adjustment article?

 

 

[Rich S]

No I followed the Haynes manual rotating each cylinder to where the lobes were flat on the cam at tdc for each cylinder while  adjusting the valves 

[tech71]

1 hour ago, Rich S said:

-set distributor to slightly behind #1 cylinder when at tdc going off of marker on timing chain pulley and oil bar. 
 

This one has also got me scratching my head, what does it mean? Never mind I think I get it now,  so does you rotor line up with the mark on dist. at #1 TDC?

 

1 hour ago, Rich S said:

any thoughts are welcome!

OK..

1. We need more to go on like:

 Was it running ok before you began work?

 Did you remove the distributor?

What kind  of non points electronic ignition set up? Fresh install ?

2. That new coil says "no external resistor required" but your  stock external resistor is still in the circuit  as evidenced by those voltage readings., they seem odd.

3. Are you absolutely certain your plug wires are in the correct firing order? 

4. What is that big fat capacitor (silver can) on your firewall for?

5. Float level on that new weber ok?

 

Edited March 6 by tech71

[Rich S]

1. Purchased about a month ago. Motor and trans out. Went through the top end. New head gasket. Distributor has been moved in order to have it pointing correctly at #1 when #1 is at tdc.

2. new to the 02’ life so looking for guidance on pigtailing or properly wiring to coil. 
3. absolutely positive plug wires are in correct firing order. 
4. excellent question regarding capacitor….no idea…previous owner stuff. 

[tech71]

6 minutes ago, Rich S said:

Purchased about a month ago. Motor and trans out. Went through the top end.

Check the compression. Time to start figuring out what its not by process of elimination

[John76]

Are you sure you connected the new coil correctly?

Something looks a bit fishy with your multimeter readings.

Check the wire from the external resistor to the to the coil +.

Should only have a wire to dizzy on the coil - (and/or tach or speed relay if fitted).

 

[Rich S]

Definitely not sure on correct coil connection. I’ll revisit tomorrow and reply. Thank you thus far. 

[TobyB]

Ok, circled in red- what's that?  It LOOKS like two wires kinda twisted together without any insulation...

 

Circled in green is the end of the plug wire where it comes loose, unscrews, and overheats if you don't have the 

heat insulation exhaust manifold gasket from an E21.

 

t

 

[Mike Self]

11 hours ago, tech71 said:

4. What is that big fat capacitor (silver can) on your firewall for?

I can at least take this out of the equation:  on pre-modell 71 cars, that's the electro-mechanical wash-wipe timer for the windshield wipers.  With the modell 71 cars, that was incorporated into a relay that lives under the dash, next to the turn signal relay.  So...that's not part of the problem here.  At least it shouldn't be 😁.

 

mike

[Rich S]

@Toby haven’t seen any photos to refer to what you are talking about.

[Rich S]

12 hours ago, John76 said:

Are you sure you connected the new coil correctly?

Something looks a bit fishy with your multimeter readings.

Check the wire from the external resistor to the to the coil +.

Should only have a wire to dizzy on the coil - (and/or tach or speed relay if fitted).

 

1. Do I need the external resistor inline with anything since it is electronic ignition?

2. The green wire from resistor goes back to ignition, not to coil. Black wire from ignition goes to coil. 

[TobyB]

shit, sorry-

 

[MurphinDC]

No need for the resistor if you're using a Pertronix type of electronic ignition.  Just leave it in place and tie the two wires together

 

Murph

[2002iii]

Welcome to the best 02 community.

 

If you suspect a dead cylinder try removing the spark plug wires one at a time with the engine running. If you remove a wire and the engine speed doesn't change you've found your dead cylinder.

 

Most electronic ignition system's don't use a ballast resistor.

 

I would suggest comparing your wiring to the factory wiring diagrams. You should also check all your connections for corrosion and looseness.

 

We need @John76 and his great wiring diagrams.