Georgia Fiero Club Forum
All Things Fiero => Tech Tips, Tech Questions => Topic started by: NoobKevin on September 04, 2019, 09:43:15 pm
-
I believe I have a cylinder that is not firing or I am so unfamiliar with a v6 at idle and I am chasing rabbits and squirrels. Timing light shows all 6 are getting coil voltage. Replaced all injectors. Do I pull plug wires like back in the day or is there a better way?
-
Perhaps using an infrared temp sensor would help. Check the temp of each cylinder. A cylinder that isn't firing should be cooler.
-
Pulling wires would identify it, but it can also put a load on the ignition control module, causing it to fail. Generally the V6 runs rather smoothly. If there is a misfire, it would be pretty noticeable.
Check the front bank to be sure you have the spark plug boots fully seated onto the plugs.
-
#1 cylinder is misfiring badly. Plug is wet and black. Can't tell if it's oil or fuel. New injectors all around. I swapped in a used plug and same misfire. Plenty of spark coming from the distributor. Trust me on this one. :o
I read compression can be a factor. Could valve lash set improperly also be a factor? Could it cause a compression issue? Guess I should check compression instead of rambling.
-
Yep, check compression. That will test the seal of the piston/rings/cylinder, the head gasket, and any leak at the valves.
-
What is the status on this?
-
Hi All,
I spent last week in Michigan where I worked alongside a car guy. We talked about valve lash and how it’s set. The nuance about setting lash escaped me. I was encouraged to set the base so the rocker just made contact with the pushrod and to not focus on the spinning sensation of the pushrod as the indicator. I used this approach as I rotated the motor one cylinder at a time, rolling the motor four complete rotations. I used the rotor cap as a visual and the increase in resistance to approximate cylinder position. I used the rocker arm movement to find the zero play point. Once satisfied with the zero lash, I set all valves by a 270 degree additional turn on each nut.
I fired it up tonight and it is purring with just a slight idle fluctuation. I haven’t even set the timing. I may have to pull the manifold apart again because the front valve cover may be leaking. But I have that process down to about an hour now. It sounds so cool.
-
Glad to read the progress, and thanks for the update.
The slight fluctuation in idle is probably normal.
-
On a fresh startup after battery disconnect, my car runs horribly. Runs rich, too, but it sounds like it's got a pretty mean cam in it. It takes a little bit of driving at operating temperature before the ECM relearns and the engine smoothes out.
-
That must've made for some good times during RFTH.
-
Charlie has the hotrod, didnt seem to bother my car at all