Loss of power after New Wires and Plugs

[mordecaibrown]

On my 1977 Porsche 911s, Me and a friend of mine changed the plugs and wires as it was it was miss firing under load, but did have good power! I was told by a local import shop that it needed new wires,plugs and maybe a coil. We put new wires on and plugs. We also had a new distributor Cap and a new ingision rotor part # 911 602 928 00/14 Now it seams NOT to be miss firing but has no power and runs a bit rough. Wire set Part # 911 609 061 00 & pugs were 7992 WR 5 DC+ Any suggestions?

Thanks

Sam

[Rich Gas]

Check the gap on your plugs...mine runs much better with a wider gap than specs. .038-.04

[kodioneill]

Check timing.

[911pcars]

Check and confirm the correct firing order on cap and plugs.

Question: Did you compensate the import shop for their diagnosis? If not, you're paying for it now. Some call it karma.

If you did compensate them, next time try another shop. Sounds like an initial over-sell. Unless the existing parts were trash to begin with, it's rare when three items, even in the same system, decide to expire simultaneously and create one symptom, but it CTA (T= their) and sells more product. If they were on their game, they probably would have pinpointed the source of the misfire.

MHO,
Sherwood

[HawgRyder]

Have a close look at the underside of the new rotor and compare it with the new one.
Some of them do not line up the same (in reguards to the pin or flat that indexes them).
What this does is change the advance of the spark.
Perhaps the new rotor has retarded the timing slightly.
The same can also be true for the dist cap.
Always check the timing whenever you do ANY distributor work.
Bob

[Paulporsche]

Are the points good?

[mordecaibrown]

Thanks all for your replies I will try your recommendations!!

[mordecaibrown]

I replace the new rotor & cap with the ones we took off and she start up better and idles smoother. Still some lost of power. the only other thing we changes besides he spark plug wires were the plugs. The original owner had W 7 DC and we replaced them with WR 5 DC This engine was total rebuild about 3000 miles ago before I bought the car. The car had no loss of power before we changes these part. just misfired under load.

[911pcars]

Continue regressing. Install the orig. plugs and see what happens. We assume you gapped them correctly and didn't slather lube on them?

Sherwood

[steve911T]

After messing around with my T for several years of poor performance after changed plugs, wires, cap rotor, rebuilt/curved distributor, rebuilt webers, etc. took it to a primo Porsche repair shop near Baltimore and what did they find, the aftermarket plug wires were bad. I have not gotten the car back yet but will pursue this to a least get the $ back for the wires. That was the only thing I did not check. Steve

[Bob Kontak]

Originally Posted by Paulporsche

Are the points good?

If you have not checked the points you have overlooked a huge driver in how the car runs.

Go over everything basic. Are the wires on correctly? 162435 clockwise rotation of distributor..

Are the wires on the plugs?

Rev the car up by hand while looking into the engine compartment when it's dark and your eyes have adjusted.

[al lkosmal]

It is a very common mistake to install the plug wires in the wrong order. triple check this.

regards,
Al

[mordecaibrown]

I will try putting back the W 7 DC plugs they only had about 3K miles on them. And I assume they were put in when the engine was rebuilt

Thanks,

Sam