jamesf1972

I have a 1600 dual port its misfiring and backfiring the intake for 3 and 4 cyls stays cold and 1 and 2 is hot. when i remove a plug wire from 1 or 2 the motor almost stalls when 3 or 4 is removed it does very little spark is good plugs are new any help would be great

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jmlloar
Check compression 1st. if its low check valve clearance. (While vave cover is off turn engine over with coil unhooked and watch to see if ALL the rockers move) if clearance is ok do leakdown test to see if its vavles or rings.

compression and leakdown tests can tell you alot
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68autobug

 
Hi,
it seems unusual for both cylinders to stop firing..
check to see there is plenty of spark on that side..
 
I would think that maybe its a spark plug lead or distributor problem... distributor caps and rotors should be replaced
every few years if not sooner..
 
check inside the distributor cap to see if you can see any problems...  wipe the inside of the cap with gas or WD40 etc
in case there are some hairline cracks..
check the rotor also..
and the button in the top of the dizzy cap [inside]
 
If the spark plug leads aren't the wire type, then they can breakdown inside..
and they don't last long either...
 
if you had a couple of spare leads off another vehicle
You could try them to see if the spark is the problem..
or take the spark plug leads off 1 & 2 and put them on 3 & 4
 
first mark the numbers on your dizzy cap 1-2-3-4
and on the leads before You change them..
[any questions just ask]
 
You only need Spark, Gas and air for the engine to operate
and seeing the other two cylinders are OK
My guess is spark...
 
or Maybe your head has come loose.?? [3 & 4]

or the rocker shaft has broken? or come loose..
have You checked the tappets? [3 & 4]
 
have you checked the rubber connector on the inlet manifold?\
they do crack and leak... [3 & 4]
inlet manifold not leaking??
spray WD40 onto them with the engine going... if the WD40 is sucked in the engine should rev...

 
Lee
 
 

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fatalifeaten
Swap 3/4 wires, I'd bet you a dollar they're backwards.
Daily Driven Dubz Phoenix AZ Family


'66 Deluxe
'63 Deluxe ragtop
'61 Deluxe
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jmlloar
The backwards thing could be true.

But it goes more like....

You need fuel, compression, and spark. Air is a given because if you have something not letting air in, compression will be low / not letting air out, compression will be high.
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68autobug

fatalifeaten wrote:
Swap 3/4 wires, I'd bet you a dollar they're backwards.


Only a dollar ...  

if that is the problem , well, its easy fixed and doesn't cost anything...

I hope You are correct...

OK on the compression [not air]

Lee


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Rusty
I had the same problem ,# 3 and 4 cylinders seemed dead ,popping through carb,only running on 1 and 2.
The problem was the vacuum line from the purge valve for the fuel vapor canister was cracked in half.And since it draws from the intake on the # 3 and 4 cylinder side its drawing all air and no fuel so the two cylinders are dead.A cracked intake boot will cause the same thing too,As mentioned earlier.
Hope this helps.
Rusty
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68autobug
 
 
We were lucky
 
We never had purge valves
 
or dashpots etc on our VWs..
 
Lee
 
 
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DOM
VW Whiz Kid.   I think I love you [smile]  I absolutely owe you a dollar.  VW whizkid said to check cylinders 3 & 4 to see if they were wired backwards  THEY WERE.  I have a new care and don't have to take the engine out. Thank you very very much, Whizkid and Samba.
Dave
DOM
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