1986 chevy pickup c10

hello i need help we have a 1986 chevy pickup and it quit running all
at once,it has a 305 eng,it is getting fuel we have changed filters
and the carb shows to be getting gas,so i started looking at the
distributor and timing i replaced the cap and rotor.also replaced the
ignition module ,it is getting fire to the plugs as i have tested it
with my inline spark tester,it wants to start but but it want,so i
started to check the timing,set #1 to TDC and looked at the rotor and
it shows to be almost at #3 if not right on it and not at #1 as it
should be,the timing chain seems to be ok as the mark comes around to
the marks on the bal wheel whch should be set at 4*
when i turn over the eng. the rotor seems to be moving slow could this
be the problem with the distributor shaft or something else.just a
little hist on the motor the ECM has been bypass as i see it at the
distributor wiring with the jumper is there something i am missing any
help on this thanks in advance

> started to check the timing,set #1 to TDC and looked at the rotor and
> it shows to be almost at #3 if not right on it and not at #1 as it
> should be,the timing chain seems to be ok as the mark comes around to

Okay, problem #1 identified.

> the marks on the bal wheel whch should be set at 4*
> when i turn over the eng. the rotor seems to be moving slow could this
> be the problem with the distributor shaft or something else.just a

The distributor should make one revolution for every TWO revolutions
of the crankshaft. So go check it.

Looking at the big picture however, If it quit all at once, and since
you said that it was running and now it isn't and you find the rotor
pointed to the wrong plug wire, there are a few things that can cause
that problem, and #1 on the list in my book would be the timing chain
and gears. Pull the distributor and check for damage to the drive gear
there, but I think you're probably looking at a timing gear set to get
it fixed up. It's not a terribly difficult job.

Chris

> wrote: 1986 Chevy C10 pickup 305

It suddenly quit running. I replaced filters, cap, rotor and
ignition module.

It is getting fire to the plugs and the carb is getting gas.
It wants to start but but won't.

When I set the #1 piston to TDC the rotor is pointing at #3.
The timing chain mark meets the mark on the bal wheel ok.

Is there something I am missing?
________________________________________________

When it quit, was it like the ignition was shut off or like it
starved for gas? Did it make any sound or vibration?

How do you know it wants to start? Does it run then quit,
or backfire, or do nothing but crank without firing?

Turn the engine over one more time until it reaches TDC
again. To time the distributor, the #1 cyl must be at the
compression stroke TDC, not the exhaust stroke TDC.

Check for a broken coil resistor. When the coil resistor
breaks, the engine quits. Then when you turn the key to
the START position the engine fires and starts running but
when you release the key to the RUN position it quits again.

Good luck.

Rodan.

On Jun 4, 2:24 am, "Rodan" > wrote:
> > wrote: 1986 Chevy C10 pickup 305
>
> It suddenly quit running. I replaced filters, cap, rotor and
> ignition module.
>
> It is getting fire to the plugs and the carb is getting gas.
> It wants to start but but won't.
>
> When I set the #1 piston to TDC the rotor is pointing at #3.
> The timing chain mark meets the mark on the bal wheel ok.
>
> Is there something I am missing?
> ________________________________________________
>
> When it quit, was it like the ignition was shut off or like it
> starved for gas? Did it make any sound or vibration?
>
> How do you know it wants to start? Does it run then quit,
> or backfire, or do nothing but crank without firing?
>
> Turn the engine over one more time until it reaches TDC
> again. To time the distributor, the #1 cyl must be at the
> compression stroke TDC, not the exhaust stroke TDC.
>
> Check for a broken coil resistor. When the coil resistor
> breaks, the engine quits. Then when you turn the key to
> the START position the engine fires and starts running but
> when you release the key to the RUN position it quits again.
>
> Good luck.
>
> Rodan
the eng trys to start,but it shows a little back pressure through the
carb and quits and trys to start again ,this has a coil thats built
into the diston top,if the coil was out it would not fire at all,the
plugs are firing as i checked them with my inline tester the dist and
rotor i replace ,but it did the same thing as before i replaced it,as
for the quiting all at once it made no sound or vibration just
died,ignition was shut off

Hal wrote:

> Looking at the big picture however, If it quit all at once, and since
> you said that it was running and now it isn't and you find the rotor
> pointed to the wrong plug wire, there are a few things that can cause
> that problem, and #1 on the list in my book would be the timing chain
> and gears. Pull the distributor and check for damage to the drive gear
> there, but I think you're probably looking at a timing gear set to get
> it fixed up. It's not a terribly difficult job.
>
> Chris
>

My buddy bought a 73 Grand Prix with a 400 that had a worn timing chain.
We were able to diagnose it by pulling the cap and turning the crank
pulley with a breaker bar. You could turn it backwards until it started
moving, and then forwards - we moved the breaker bar about 45 degrees
until the distributor started moving. IIRC, we then pulled the fuel
pump and felt the chain through the access hole (it's been 12+ years so
my memory is a bit hazy but I think you could do that on a pontiac) and
the chain was all sloppy.

Ray

Rodan wrote:
>
> Check for a broken coil resistor. When the coil resistor
> breaks, the engine quits. Then when you turn the key to
> the START position the engine fires and starts running but
> when you release the key to the RUN position it quits again.
>
> Good luck.
>
> Rodan.
>
>
>

or even possibly a bad coil. Buddy's 72 Nova quit on the highway about
200 miles from home. Had it towed to a hotel, called me. I grabbed a
spare dist assembly (and other parts) and went down there. No spark,
and the module I had wasn't the same, so we bought one in the morning
and it still wouldn't start. We then noticed a crack in the epoxy
around his Accel supercoil... and swapped it back for a stock one.
Started right up.

(his Nova was a 6 cyl, but was a 350 with an HEI ignition.)

Ray

On Jun 3, 5:37 pm, wrote:
> hello i need help we have a 1986 chevy pickup and it quit running all
> at once,it has a 305 eng,it is getting fuel we have changed filters
> and the carb shows to be getting gas,so i started looking at the
> distributor and timing i replaced the cap and rotor.also replaced the
> ignition module ,it is getting fire to the plugs as i have tested it
> with my inline spark tester,it wants to start but but it want,so i
> started to check the timing,set #1 to TDC and looked at the rotor and
> it shows to be almost at #3 if not right on it and not at #1 as it
> should be,the timing chain seems to be ok as the mark comes around to
> the marks on the bal wheel whch should be set at 4*
> when i turn over the eng. the rotor seems to be moving slow could this
> be the problem with the distributor shaft or something else.just a
> little hist on the motor the ECM has been bypass as i see it at the
> distributor wiring with the jumper is there something i am missing any
> help on this thanks in advance

I think the other Ray is on the right track. Turn the engine by hand
in one direction with the distributor cap off until the rotor is
turning. Then reverse direction until the rotor turns again in the
opposite direction, this should happen almost immediately. If it
doesn't most likely cause is a worn chain. Although extremely rare a
chain can skip.

Also very rare is the pin in the distributor gear breaking. They can
appear OK when turning by hand but slip when cranking.

Good luck.

> wrote: 1986 Chevy C10 pickup 305

It suddenly quit running. I replaced filters, cap, rotor and ignition module.
It is getting fire to the plugs and the carb is getting gas. It wants to
start but but won't. When I set the #1 piston to TDC the rotor is
pointing at #3. The timing chain mark meets the mark on the bal wheel ok.
Is there something I am missing?
________________________________________________

When it quit, was it like the ignition was shut off or like it starved for gas?
Did it make any sound or vibration? How do you know it wants to start?
Does it run then quit, or backfire, or do nothing but crank without firing?
Turn the engine over one more time until it reaches TDC again. To time the
distributor, the #1 cyl must be at the compression stroke TDC, not the
exhaust stroke TDC. Check for a broken coil resistor. When the
coil resistor breaks, the engine quits. Then when you turn the key to the
START position the engine fires and starts running but when you release
the key to the RUN position it quits again. Good luck. Rodan.
__________________________________________________

When it quit, there was no noise or vibration, just died like the ignition
was shut off.

The eng tries to start, shows some back pressure through the carb,
quits and tries to restart.

The coil is built into the distributor cap. The plugs are firing. I checked them.

It did the same thing before I replaced the dist and rotor.
>
__________________________________________________ _____

Then it gets back to timing: Timing chain slipped, Distributor clamp bolt
loose, Distributor gear shear pin broken. To time the distributor, the #1
cyl must be at the compression stroke TDC, not the exhaust stroke TDC.

From the carb backpressure I would think of a burned valve or a collapsed
exhaust pipe, but these conditions should not result in such a sudden
shutdown. Another possible condition: carb fuel input fitting mostly
plugged or carb needle valve sticking almost closed.

I hope you will post again when you find the problem.

Good luck.

Rodan.

Timing chain jumped.

You can check for slop in it easily. You take off the distributor cap
and turn the engine a little clockwise until the timing mark on the
crank lines up. You then watch the rotor and turn the engine the other
way while paying attention to how far the crank moves before the rotor
starts moving back. This will be the slop and should likely be less
than 15 degrees or so.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

Rodan wrote:
> > wrote: 1986 Chevy C10 pickup 305
>
> It suddenly quit running. I replaced filters, cap, rotor and ignition module.
> It is getting fire to the plugs and the carb is getting gas. It wants to
> start but but won't. When I set the #1 piston to TDC the rotor is
> pointing at #3. The timing chain mark meets the mark on the bal wheel ok.
> Is there something I am missing?
> ________________________________________________
>
> When it quit, was it like the ignition was shut off or like it starved for gas?
> Did it make any sound or vibration? How do you know it wants to start?
> Does it run then quit, or backfire, or do nothing but crank without firing?
> Turn the engine over one more time until it reaches TDC again. To time the
> distributor, the #1 cyl must be at the compression stroke TDC, not the
> exhaust stroke TDC. Check for a broken coil resistor. When the
> coil resistor breaks, the engine quits. Then when you turn the key to the
> START position the engine fires and starts running but when you release
> the key to the RUN position it quits again. Good luck. Rodan.
> __________________________________________________
>
> When it quit, there was no noise or vibration, just died like the ignition
> was shut off.
>
> The eng tries to start, shows some back pressure through the carb,
> quits and tries to restart.
>
> The coil is built into the distributor cap. The plugs are firing. I checked them.
>
> It did the same thing before I replaced the dist and rotor.
> >
> __________________________________________________ _____
>
> Then it gets back to timing: Timing chain slipped, Distributor clamp bolt
> loose, Distributor gear shear pin broken. To time the distributor, the #1
> cyl must be at the compression stroke TDC, not the exhaust stroke TDC.
>
> From the carb backpressure I would think of a burned valve or a collapsed
> exhaust pipe, but these conditions should not result in such a sudden
> shutdown. Another possible condition: carb fuel input fitting mostly
> plugged or carb needle valve sticking almost closed.
>
> I hope you will post again when you find the problem.
>
> Good luck.
>
> Rodan.
>
>