1987 Honda Accord Carburated Automatic About 3 Months Ago Would Misfire

1987 HONDA ACCORD

158,000 MILES

GGMITCH123

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I have a 1987 Honda Accord carburated, automatic. About 3 months ago it would misfire occasionally while driving, then it started to do it even when I was stopped, then about 2 months ago it just died and wouldnt start. It would backfire and spit puel out of the carburator. I had a mechanic check the timing and the timing is good. I changed the distributor with a used one from the junk yard, after that we started the engine and it ran good, so we put all the parts back on and then it would not start again.
I now know it is the 4th cylindar causing the issue. The car will sometimes start with all 4 spark plug wires on it, but will die quickly. The car will start and run on 3 cylindars. If I connect the 4th spark plug wire the engine will stop running. We replaced the head gasket and valve seals and cleaned all the valves.
My mechanic tested for spark with a spark tester and when the 4th cylindar spark plug wire is not connected to the spark plug the tester light will pulsate normally, however when the wire is connected to the spark plug the tester light stays on constantly.
I have changed the spark plugs, spark plug wires, distributor cap and rotor.
What could be the problem?
Thank you

Oct 31, 2012 at 9:48 PM

KHLOW2008

CAR REPAIR CONTRIBUTOR
41,814 POSTS

Check the engine compression. Check for vacuum leakages at the intake manifold.

Oct 31, 2012 at 10:16 PM

GGMITCH123

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We already checked compression and it is good. I changed some of the vaccum lines but that didnt make a difference.
What is the bes way to check for vacuum leaks?

Oct 31, 2012 at 10:21 PM

KHLOW2008

CAR REPAIR CONTRIBUTOR
41,814 POSTS

A vacuum gauge attached to the intake manifold would indicate the vacuum present. Spraying suspect vacuum leaking area with carb cleaner would change the engine idling.

Check the valve clearance.

Oct 31, 2012 at 10:27 PM

GGMITCH123

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5 POSTS

Thank you, I will try this.
should I spray the carb cleaner with only 3 cylindars running? I dont think it will run long enough with all 4 plug wires connected.

Oct 31, 2012 at 10:31 PM

KHLOW2008

CAR REPAIR CONTRIBUTOR
41,814 POSTS

Are you sure the firing order of the spark plugs are correct?
You might have only 2 cylinders firing which are usually due to a bad PCV valve.

With 3 cylinders you might not be able to notice any difference when vacuums are detected.

Nov 1, 2012 at 5:45 PM

GGMITCH123

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5 POSTS

I am sure that all the wires are in the correct firing order. I can try replacing the PCV valve to see if that fixes it.
Thanks

Nov 1, 2012 at 5:49 PM

KHLOW2008

CAR REPAIR CONTRIBUTOR
41,814 POSTS

Use a circlip plier to clamp on the PCV hose and see if the idling improves. Hose is at center of intake manifold and is an inverted U-shaped hose.

Nov 1, 2012 at 5:54 PM

GGMITCH123

MEMBER
5 POSTS

Thank you.
Also, Im having another issue. My first mechanic stripped the key hole on my crankshaft for my harmonic balancer, we have tried many fixes that do not work. Im going to replace the crankshaft. Is this a somewhat simple fix? Can I just pull out the crankshaft after removing the crankshaft pulley? Of will I have to take the engine apart?
Thanks

Nov 1, 2012 at 6:11 PM

KHLOW2008

CAR REPAIR CONTRIBUTOR
41,814 POSTS

No, this is not a simple fix. Crankshaft replacement requires the engine to be taken out of vehicle and oil pan, oil pump, end seals etc to be removed.

How badly is the key way damaged?
On vehicle it might not be easy to repair but a few mig spot weld and filing it down to size might allow you to install the key.

Nov 1, 2012 at 6:20 PM

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