Help! Desperate! New engine mounts = 50% loss of power

[skinnerd]

The other night I installed a new set of motor/transmission mounts on my 73 RS replica with a 3.2 Motronic.

After installing the mounts, I went out for a test run, and the car is now noticeably down on power.
It still starts easily and idles well, but when you get on the throttle, it feels like it has about 120hp instead of the normal 240hp (SSI's, Wong chip, throttle body, sport cams, sport exhaust, etc).

To install the mounts, I lowered the engine down ~4 inches max to do the engine mounts, and maybe 2" for the trans mounts.
What happened?
Did I dislodge some wiring, or induce a leak in the induction somewhere?

Does anyone have a clue or can give me some things to quickly check out?
Thanks in advance.
I was signed up for the Pro Solo at Packwood this weekend, but with the car running as it is, it will be fruitless to show up.

This board is always great with the advice....maybe you can help me with my problem so I can still go play this weekend.

[Netspeed]

If all the chassis grounds look good, I'd re-lower the engine a little bit at a time to mimick the mount replacement. Then start looking at any potential wiring problems.

[rlh930]

See if you kinked one of the hard fuel lines.

[Bobboloo]

Ditto what Roger said.

Also, did you un-hook the throttle linkage when you lowered the motor?

If you didn't you might have bent the linkage. Check and see if pressing the gas pedal all the way gives you full throttle.

[Jack Olsen]

What Bobby said. Trace out the throttle cable from the tunnel to the throttle, and have someone press the pedal all the way to make sure you're getting full throttle.

[skinnerd]

Thanks all....
I'll give a quick look to see if that is the problem.

[Steve@Rennsport]

Doug:

Since I know you are getting full throttle, the above suggestion that a fuel line(s) might have been inadverently damaged makes it worth checking the fuel delivery rate at the rail.

Make sure that the pump fills a 1 litre container in about 30 seconds and that you have 2.5 bar of fuel pressure with the engine off (needless to say) and the pump bridged "on".

[skinnerd]

I guess that is true Steve.
Jeff did insure I was getting full throttle when he did his work.
I have gone through the wiring, checking all the connections...they all "look" sound.
I haven't checked fuel delivery volume or pressure yet.
Will see if I can get it done tomorrow and still get to the event on Saturday morning.
Thanks!

[Steve@Rennsport]

Hi Doug:

One thing that comes to mind (thanks to Sherwood) is the possibility that the exhaust system was somehow damaged and the muffler is constricted.

Lastly, the crank position & reference sensor, cables, connectors might have gotten damaged or partially dislodged and that will REALLY change the ignition timing. Thats a recipe for a big power drop.

[skinnerd]

Not the exhaust system.
SSI's in great shape, and I've flipped through a couple different mufflers with no change.

I'll check the flywheel sensors, fuel lines, etc....

[Bobboloo]

In particular, check the hard lines inside the engine compartment where they meet the fuel hoses that go to the motor. If you lowered with these connected a hose could have bent the hard line.

[skinnerd]

Thanks Bobby...I'll definitely check for those.

[MXMARK]

How did it turn out? Was the engine wire harness loose? Mark

[Wayne 962]

Originally posted by Jack Olsen
What Bobby said. Trace out the throttle cable from the tunnel to the throttle, and have someone press the pedal all the way to make sure you're getting full throttle.

On a sidenote, this is the number one problem with most 911s not achieving full power - the accelerator linkage is simply not fully engaged!

-Wayne

[skinnerd]

Well...this is the status as of Sunday night.
I spent some hours this weekend going over all the electrical connections, fuel lines, induction (looking for obvious leaks), etc.
Nothing looked out of place.
I know I have full accelerator linkage travel.

I went to register for the Parade today with a buddy of mine, and the car was just down on power.
His 77 2.7 CIS was leaving me behind.
So I registered, teched the car for the auto-x on Thursday, checked out the Porsches prepping for the concours tomorrow, and headed back to our favorite brewpub for a cold one before heading home.
I placed an emergency call with the local Porsche repair shop pleading for a quick fix to my problems.
On the way home, after leaving my friend, I noticed the car seemed to have better pickup than the past couple of weeks.
So I started to explore the car a bit....
And by God, it seemed like the power was picking up somewhat.
Well, after many spirited 0-60 runs on the way home, and checking out the power delivery in a couple of the lower gears, its seemed like the engine was running like it used to.
It would rip through 1st gear to 7000 grand in no time, and would pull very strongly through 2nd and 3rd gears as well.
I was up to 90 in no time.
Mystery of the century.
Seems like I am back on full power again.
And due to nothing I really did I believe.
Any ideas????
I have heard sometimes chips need to learn the car.
But when I initially installed Steve Wong's chip, the power was good right from the get go.
So I am stumped.... but happy to have a healthy 3.2 again.
Not sure if this will ever be solved.

Thanks for everyone's inputs.
As usual, the Pelican community was there to lend a hand or give a suggestion.
Thanks to all.

[PatrickM]

How many beers did you have before noticing the resurgence of power?

[J P Stein]

Originally posted by skinnerd

So I started to explore the car a bit....
And by God, it seemed like the power was picking up somewhat.
Well, after many spirited 0-60 runs on the way home, and checking out the power delivery in a couple of the lower gears, its seemed like the engine was running like it used to.
It would rip through 1st gear to 7000 grand in no time, and would pull very strongly through 2nd and 3rd gears as well.
I was up to 90 in no time.
Mystery of the century.
Seems like I am back on full power again.

Doan matter none....I'm still gonna whip ya like a dog in the street.

[skinnerd]

Mr. Narp....you are so toast!

[Jack Olsen]

Exhaust obstruction, maybe? Do you have a catalytic converter?

[skinnerd]

Jack:

I just have SSI's and one of those m&k exhausts.
No catalyst or any other such things.
So I don't think it is the exhaust system at all.
This is a really strange thing, I must say.

I will get out again tonight to run the car hard around the back roads to make sure it is still running at full power again.

Not sure what to think about this all right now.
The Parade auto-x is on Thursday afternoon for me, so hopefully my problems are behind me.