Spark cuts out with too much throttle

[Anonymous]

We've eliminated the carb as a problem for our engine. We took out the yfa and put a rbs in without emissions junk on it and it still cuts out. We also watched a spark plug and discovered that if you give any more than 1/4 throttle the spark stops. The engine is a 250 out of a 78 granada with emissions removed and dual oulet headers. We are also using a MSD 6A box with the magnetic pickup adapter. I'm going to summit today to buy a new msd ignition box to see if that is the problem, it it isn't, i'm out of ideas. Any help would be appreciated.

 

[addo]

Check your pickup for continuity. Sounds like a blown winding.

 

[CobraSix]

What kind of pickup are you using? DS2? Pertronix? I would guess that is the problem. Also, you cap and rotor may be worn out. Possibly your coil. I wouldn't think the MSD at first, especially since it is the most expensive part.

Slade

 

[Anonymous]

I am using Duraspark dist, whatever is stock, the cap, rotor and coil are new, wires are new, plugs are new.... The MSD I purchased second hand, and the seller claimed it 'worked when removed', which was again, a claim. The motor ran perfectly fine with the factory setup before I removed it from the donor car.

 

[CobraSix]

Have you had this problem since you put the MSD in? If so...then I think you have the right item to look at.

Slade

 

[MustangSix]

Take a look at the reluctor on the DS II and make sure it's not hitting the pickup coil. I've run across a couple that had bent retaining ears on the advance plate that allowed the coil to make contact as the advance plate moved.

 

[Anonymous]

Well, we just put the new msd on and sure enough it was the msd, the car runs great now. The old msd was a model 6A, but it looked different and had a weird 4 prong plug hanging off it. I think it must be an older version of the 6A. I'm not sure what i'm going to do with the old one, since it's different it might be ok, just wired wrong. I'll have to look into it.