911T 2.0 , but power should be better shouldn't it?

[Rich911E]

I have a weird sort of problem that I would welcome any potential suggestions to look at over the weekend. I installed a 2.0 911T motor to use while I rebuild my other engine. The engine seems to run fine down the highway or whatever, but just has no power to accelerate above about 3000 RPM.

The motor is a stock 1969 911T with 40IDA Webers, headers with stock muffler, Mallory Hy-Fire IV ignition and coil and Accel plug wires. Initial timing is at TDC, haven't checked the 5000 RPM timing and might be a source but distributor seems OK. Engine is tight (clean exhaust, plugs not fouled). I have been through the carbs and they are OK. 30mm venturis, 140 main jets, 180 air corrector jets, 50 idle jets. Fuel pressure correct.

Is there some reason why the car just lays down and will not pull. I am thinking ignition, but this ignition worked in a 2.4 just fine before I had head stud "issues". Plugs were lean initially before, but when I went to 140 mains, it seemed to be a lot better and plugs look right. The tach (Mallory) is acting funny -- reads very high like 2-3 times the actual RPM. Is there a potential problem with the tach that is affecting the ignition?

Thanks in advance for your help.

Rich Murphy

[Early_S_Man]

Rich,

You may or may not have ignition problems, but if you went from a 2.4 'E' engine to a 2.0 'T' in the same car, you must face the fact that you lost 55 hp, and quite a few revs off the top end! The '69 'T' engine only has 110 hp, and it comes 400 rpm lower than your 'E' engine. Your top speed drops to about 125 mph!

------------------
Warren Hall
1973 911S Targa
1992 Dodge Dakota 5.2 4X4 parts hauler

[Rich911E]

Warren:

Thanks. I realize that the 911T engine is pretty anemic, but it seems like it pulls for a little bit and then lays down. I don't expect it to run like the 2.4E engine, but should pull to about 5000/5500 RPM. Right now it is laying down about 3000 and very slowly will accelerate up. (If I raced a Civic it would beat me.) It will rev higher up to 5000+ RPM (which is why I think it is getting enough fuel), but it takes a million years to get there. Could it be the accelerator pump-shot that is not giving it the mid-range fuel boost it needs?

Rich

[Rich911E]

Any ideas on this before I spend the weekend going in circles?

Thanks again, Rich

[911pcars]

Rich,
I noticed you checked fuel pressure, but did you check fuel volume? The symptom you describe sounds like you're running out of fuel on demand. Not sure what the spec is. I think this was addressed on another, recent "engine stumbling" thread.

Sherwood Lee
http://members.rennlist.org/911pcars

[Rich911E]

Thanks for the idea on total fuel volume. I tried searching the archives but couldn't find anything. I would be surprised if the fuel volume were the problem as this is the same fuel system that supplied the 2.4 engine and it ran to 6500 with no problem, but you may be right -- it just sounds like it is running out of gas. I may try removing the fuel filter to see if it is a restriction. It looks clean but maybe it is plugged. I may increase the idle fuel pressure a bit and see if this helps -- at least it might point me down the right track. I will also check the float level again.

Thanks again for your suggestions.

Rich