Engine Vibration 1991 B6D

[Skrapbob]

B6D with festiva electronics. I have a running B6D out of a 91 Capri. The engine and 5 spd swap were done at the same time. I have 3 new engine mounts, new flywheel, exedy clutch. Getting 35 mpg around town with my foot in it. The engine runs quiet and seems to run good. Shifts nice too.

Drivetrain vibrates anytime the engine is on, from start-up, neutral, clutch in/out. Feels it when revving. I can feel it anywhere on the car, inside and out.

Feels to me like something is out of balance.

Any help is most appreciated. hmmmmmm

[Team Lightning]

What crank pulley are you using? Mine is stock B6D and I'm not seeing any vibrations.

[Skrapbob]

The one that came with the engine. B6D I think I tried the Festiva but the pulley mounts different if I remember correctly

[Team Lightning]

All the bolts tight? Is there a miss or anything that could be a firing issue?

[Skrapbob]

Tried different coil, plugs, plug wires, distributor,cap,rotor,VAF, different fuel, rotated the pressure plate 1/3 turn.

Car starts very easy, so easy that it started up several times when just trying to bump the starter to advance the crank.

I did find that disconnecting any plug wire at the distributor causes spark to jump from out of the cap to the base of the distributor at the missing wire location.

[Team Lightning]

To me, that sounds like a bad cap and or rotor button. I'd get a new one if possible.

[FestYboy]

^ agree. Spark jump like that should be near impossible with a good cap, replace it.

[Skrapbob]

To me, that sounds like a bad cap and or rotor button. I'd get a new one if possible.

Two different caps and two different rotors...Brand new parts.
Same spark jumping out.

Weird!

[FestYboy]

So you're saying that with with different caps, you can witness the spark jump from the tower and travel the approx 2.5" distance to the dizzy chassis... While it's dry and clean?

[Rick the Quick]

Not to insult your intelligence but is there any chance you have clearance issues? Intake/ firewall, exhaust/body, etc.? It sounds like one powerful ignition coil. Maybe the high humidity is a contributing factor.

[Skrapbob]

Not to insult your intelligence but is there any chance you have clearance issues? Intake/ firewall, exhaust/body, etc.? It sounds like one powerful ignition coil. Maybe the high humidity is a contributing factor.

No insult taken. I appreciate the input. The spark is only just jumping out of the cap.

It was rather humid yesterday

[Skrapbob]

So you're saying that with with different caps, you can witness the spark jump from the tower and travel the approx 2.5" distance to the dizzy chassis... While it's dry and clean?

The spark was only just creeping out of the cap to the metal of disty, not jumping 2.5 inches. I'm guessing this is probably normal when there is no wire going to the plug. The spark has to go somewhere?

So.... Removed and cleaned the injectors. They seemed to be spraying okay before, but I have eliminated that being the issue. I think my next step is to pull the trans, pull out the brand new flywheel and clutch, and either have them balanced together, or install the old stock flywheel and clutch.

[FestYboy]

The spark was only just creeping out of the cap to the metal of disty, not jumping 2.5 inches. I'm guessing this is probably normal when there is no wire going to the plug. The spark has to go somewhere?

Wait, you've been running the engine on fewer than all 4 cylinders!?! Bob, WTH are you doing? Of course it's gonna shake!

As for the drive line vibration, since you're comfortable pulling the trans, remove the clutch disk, throw that back together and observe. Removing the clutch disk isolates the engine and trans, so if the vibration persists, you know it's not the trans. And can concentrate on the power side of things.

[Skrapbob]

I greatly appreciate the response... I really do feel like I am lacking on power a bit. But I have no baseline. I have tried pulling plug wires one at a time for process of elimination. It runs rough when spark is cut to any cylinder.

The injector clean did seem to help it start a little better. Maybe just a placebo...

I don't know what to expect from this capri engine with festiva electronics. The vibration is pretty harsh at about 3000 rpm and again above 5000 rpm. There is a slight bog (very slight) when shifting gears if under 2000 rpm. I can roast the tires from a start, and I set an all time new top speed for the car at almost 100mph, and 30+ mpg while I was at it.
:scratch:

[FestYboy]

Ok so it sounds like the cams are advanced by a tooth. That B6D should be able to easily pull 110mph.

But that's not what the OP is about so let's see if we can't isolate that harmonic vibration because that's what it is. Of something was out of wack (bent) it should shake at all speeds and get worse with RPM. What you describe is a balance issue as they show up at specific speeds and between those, it gets quiet. Much like a wheel out of balance, it only happens at "x" road speed but below and above "x" it's smooth.