Rebuilt motor problems, Help needed!!

RickKlem · 09-04-2003, 05:00 PM

I just installed my rebuilt 3.0L , I test drove it tonight for the first time. I need to seat the rings.

I had to add a front oil cooler (trombone style) because the car did not have one. The temps were 210 , I felt of the front cooler and it was cold. I know that the tstat is bad or stuck, but what temps should the car run without a front oil cooler?

Also it fells like it has no power , it's not zippy. Is this normal for a fresh engine or is something wrong? It fills like I'm dragging a bus behind me!

Help
Rick

cstreit · cstreit's Garage

Is it CIS or carb'd?

Check the basics first...

Timing, Spark, Fuel pressure, intake or exhaust restrictions, fuel quality, fuel filter, etc...

Did you build the motor, or someone else?

Wayne 962 · Wayne 962's Garage

It's not going to get up and go right out of the gate - you need to gently wear it in a bit (well, gently is a relative word). Pick up a copy of my book (http://www.101projects.com) and read the last chapter, if you haven't already...

-Wayne

RickKlem · 09-05-2003, 04:57 AM

Thanks for the response,

Chris,
It is CIS , I'm going to check the fuel mixture and timing this weekend. It has a new fuel filter, and accumalator. I cleaned the tank out when I first started this project ,so fuel is clean. The exhaust and intake is clear, I installed a new set of SSI and a new Dansk sport muffler. I did not rebuild the motor, someone else rebuilt the long block and I refitted every thing else.
And I need to mention that I would not have even tried it until I discovered this BBS and PelicanParts (Thanks Wayne and the guys)

Wayne,
Thats what I was wondering about, If the motor had to seat the rings and break in before it started to show any signs of a 3.0L motor, or was something wrong and by me test driving it making things worse. Right now it just doesn't seam as spunky as my 2.7 did that I removed. I did buy your book, and I love it. I will read up on the last chapter today at lunch.

Thanks again for every thing
Rick

cstreit · cstreit's Garage

Well a stock 3.0L will not rev as crisply as a stock 2.7 but should still feel pretty good. Why don't you also take a look at your plugs as long as your diagnosing and see what they look at.

Off-hand I'd guess a fuel thing, ignition timing, or cam timing...

1fastredsc · 09-05-2003, 06:36 AM

Any rebuilt motor is going to feel kind of "stressed" or "strained" for the first 1k or so. Especially since you had a complete rebulid, meaning not only are the rings seating but your rod bearings must set in as well, which is a lot of frictional break-in. You'll slowly feel it transform over the more you drive it. It'll probably take at least 3k or so before it'll feel normal, but the biggest changes occur in the first 500-1000 miles. Or at least that was my experience on other rebuilds.

RickKlem · 09-05-2003, 04:28 PM

Wayne , I looked at the last chapter of 101 projects, nothing about rebuilds????

Rick

mb911 · mb911's Garage

CHeck to make sure Frequency valve is operating I had the same problem and that was it along with ignition timing. Mine is a fresh rebuild and after resetting a few things it goes like like a SOB. Break in an engine should not require a loss of power or not something like a 100hps or so more like 10 -15 hps so that would not even be real noticable. Good luck

Ben
77 911 3.0
75 914-6 2.7

Wayne 962 · Wayne 962's Garage

Wrong book - check the "Engine Rebuild Book" - http://www.101projects.com

There are many people out there who believe that the 2.7 is peppier than the 3.0. I haven't done a comparible swap test (same car), so I can't tell. I do know my 914 with a 2.7S feels much quicker than my 911SC with a 3.0L

-Wayne

RickKlem · 09-06-2003, 10:37 AM

Okay, I pulled the plugs to check for running condition. All three plugs on the left where loaded with oil (running rich) and all of the ones on the right was light gray to a light white. Way would one side be rich and the other side normal or lean?

All so I found that the rear brakes are tight . I mean that spinning the rear wheel by hand you can notice a lot of resistence. I'm going to pull the caliper and check things out.

Rick

cstreit · cstreit's Garage

Rick,

Can you clarify, was there oil on the left plugs, or were they just dark?

RickKlem · 09-06-2003, 12:11 PM

There was oil and fuel (very wet) on all of the left side plugs. I wiped them off and leaned the mixture a little , I will test drive it this afternoon and then recheck the plugs.

Rick

cstreit · cstreit's Garage

Strange because with the 3.0L CIS you should get at least some semblance of mixture balance right off. THe only things that come to mind are that through a coincidence all the Right side injectors are somewhat clogged, or that the spark on the left side is weak, again, not likely.

THere is no inherent left/right balance.mixture mechanism in the motor, so the fact that it's just the left side may be a coincidence of other issues.

The other possibility that would explain how the whole left side is off would be cam timing... If somehow your cam timing was quite a bit off, this might happen...

Barring anything else, I'd double check that, because it's one of the few left/right things...

RickKlem · 09-06-2003, 04:48 PM

Is there an easy way to check it? I have never done it before. Remember , this is the same car that just doesn't have a lot of power (see the beginning of this thread). I can only drive it for about 15 to 20 minutes, the longer I drive it the slowing it gets .

20 minutes into the drive, I press the pedal to the floor and it will only rev to around 2800rpm and dropping the longer I drive it. If I take it out of gear and rev it up, it will rev higher (3800 plus).

Also I noticed that the rear bumper gets to hot to even touch after a drive. Its a Dansk sport 2in 1 out muffler with ssi (both are new). My 2.7 with factory muffler and factory heat exchangers never even made the bumper warm. Could something be cloged in the muffler ? I will try to swap the muffler from the 2.7 just to see if it makes a difference.

As for the injectors being clogged ,I pulled them all and placed them into their own seperate bottle , held the sensor plate up for 30 to 40 seconds , then compared all six bottles. They all had the same amount of fuel.

Help
Rick

cstreit · cstreit's Garage

FWIW the back bumper on my 930 and on a buddies SC always gets really hot too. May be muffler design?

There really isn't an easy way to check cam timing unless you use a dial gauge.

I think you need to start with a CIS diagnosis first, you've got equal flow, so start checking the control pressures, vacuum, etc... How much gas did you get in the jars after this amount of time?