I went for about a 120 mile cruise yesterday and while I was crusing on mild acceleration, I got the odd bockfire pop.
About 10 miles from home, the truck started poppin, shakin, and sputtering.
I pulled off the highway and chugged home on the sidestreets.

This is a 350 TPI with an RV cam, World products SR heads, and headers.

I checked fuel pressure at idle , 35 psi, I shut it down , went up to 40 and held there.

I changed the cap and rotor as it was about time anyways.
I used the timing light to check each spark plug wire for voltage and all pulsed the light.

No engine light nor any stored codes.

Coil perhaps?

Any ideas guys?

Thanks,
Pugsy

 

Fuel pressure is too low. Running lean. Fix that first. Hopefully just a filter issue.

 

I'll change that and see how it goes.

Thanks.

 

Filter changed along with a set of new plugs for good measure as its been 4 years.
Its still running the same, maybe just not as ready to stall out so quick in drive when slowing down.

When I step on the gas a bit hard it shudders and has zero power.
I'm thinking something internal maybe as the shuddering may indicate one cylinder not firing?

Its like something's out of balance.

 

Did your fuel pressure come up from what you posted?

Have you tested the coil? I know you tested for spark, but it doesn't rule out the coil.

 

I'll do a pressure test when I get home.

How does one test the coil?

Thanks.

 

The procedure and values are outlined in the manual- It basically involves an ohm meter and a few minutes. I'm at the office and don't have my manual handy

http://www.hotrodders.com/forum/test...le-103662.html

Best one I found for pictures. Might not hurt to have the module tested too. After all you've tested/replaced, you're back to fuel or air. Don't forget to grease the module, too!

 

Thanks.
I brought a new coil home with me and no change.
I retested fuel pressure and its up about 45 psi now.
No change.

Injector fuses good.
I pulled one injector fuse at a time and attempted to start.
It would only start on one bank.
Driver's side exhaust pressure also feels lighter than passenger side.
I'm thinking I may have a mechanical problem with a valve.

I will pop off a valve cover next.

Thanks again,
Pugsy

 

I pulled off plug wire #3 while running and no rpm drop.
Reversed wires #1 and #3 and same result.
Looks like injector 3 or camlobe on 3 maybe?
Valve springs, rockers and pushrods all look OK.

 

With the valve cover off, disconnect power from the distributor. Crank the engine over while keeping a close eye on the rocker arms on number 3. If you smoked a cam lobe, there will be no movement on 1 or both of the rockers. Make sure you don't have a bent pushrod too.

 

I'll be pulling into the garage tommorow for more testing.

I have a remote starter but not sure how to hook it up.

 

You *should* be able to see it by standing 1/2 in and out of the car while using the key. Easiest route IMHO. No need for a remote start.

If you have a compression tester, might as well pull the plug on that cylinder and knock 2 birds down simultaneously.

 

Thanks.

I'll be putting on the hoist soon to pull the plugs. I'll figure out the remote start then.

I may as wells run the compression test across all the cylinders while I'm at it.

 

Injector #3 toast.
Ohms out at 1.8 or something like that.
Spark plug is still like brand new though.....that's nice.....

I'm surprised by how rough the engine runs from one cylinder not firing.