My 71T just won't run

Allenk · 09-20-2002, 07:42 PM

I thought after finally getty my T to start and take some fuel, a couple of Zenith kits would do the trick, wrong. The car will start fine and will take throttle(basically from the accelerator pumps) but just won't idle properly and if I get the rpm's up and try to hold them, it seems to run out of fuel. I've set the initial settings per the manual, 2 1/2 out for mixture, 0 on auxillary air. Symptoms are random pop with flash out of the carbs and random spit of gas/fumes. I've checked the timing-not running but using the TDC of cylinder 1 at compression and it seems to be fine. I have an inline pressure regulator set at 2.5. I pulled the plugs and they are sooty/black and a couple still had fuel on them. I guess I'm torn between ignition and fuel as the problem. I need to get this resolved before I continue w/ this project or I'll just part the car out.

Tyson Schmidt · 09-20-2002, 08:43 PM

Before you go any further, get a float level gauge and check all four float levels. And pull all 6 plugs and clean them thoroughly.

Side note: I've seen gaskets for the carb top that didn't have the hole for the air bleed punched out all the way.

Allenk · 09-21-2002, 04:00 AM

I've cleaned the plugs, and will try the float levels. I also wonder about the aux. enrichment circuit. Can this be bypassed/shut down. I just want to get as basic as possible and eliminate variables.

farleyd · farleyd's Garage

Ive had the exact same problem. Checked everything and still doing this. So, dismantle your carbs and check for clogged/stuck floating valve. Thats what happened to me along with a clogged accelerator pump circuit.

Your problem lies there, pretty sure.

I got rid of the aux. enrichment circuit. Thats what you call Euro Zeniths.

Good luck.

Allenk · 09-21-2002, 08:06 AM

How does one get rid of the AUX enrichment circuit? Is it best to leave it in place and block off the lines. I'm assuming that the carb inlets would just be plugged but what about the rest? I've been through the carbs pretty good I guess I can do it again but????? The accelerator circuit seems to be fine, rebuilt and injecting with throttle.

jeff m · 09-21-2002, 10:24 AM

I would have a second look at your timing.
Check the distributor, pull it out, make sure the plate is not seized. Run some WD40 through it. Reset points, I've found it's easier to set points with dist out anyway.

Engine to tdc on firing for # 1 (that's with rotor pointing at your right soulder) and replace it without moving crank.

Check timing with strobe.

Also check for vacuum leaks

Jeff
911T

Allenk · 09-21-2002, 01:26 PM

Good suggestions Jeff, At this point it's a quick easy check. A couple of questions, with #1tdc at compression should the points be open or closed? Also what vacuum? There are no vacuum lines associated w/this distributor and I can't even get the car to idle enough to check the oil never mind put a strobe on it. I wish I could.

jeff m · 09-21-2002, 07:33 PM

they should be just opening
Try a few degrees after TDC, about a quarter inch should give you a fair chance of starting.
Jeff

stew · 09-21-2002, 09:23 PM

also check you fuel filter/filters to make sure your getting supply

Allenk · 09-22-2002, 04:25 AM

Thanks again, it will be a couple of days before I can get back to it but I'll keep you up to date.

Allenk · 09-26-2002, 04:13 AM

Update: pulled distributer and found the plate seized. Cleaned everything up and will be reinstalling hopefully tonight. Thanks people-hopefully this will put thing back on track.

Allenk · 10-02-2002, 04:31 PM

Well, distrubutor is in again and the problem remains. Interesting symptoms. The car starts right up with a couple of pumps of gas. The engine will take fuel if I feather the pedal. The car will not hold at a constant rmp if the throttle if held. The car will idle but varies from rough to smoothe(kinda like it's dropping a cylinder or 2 then it comes back). The exhaust is very rich but if I adjust the mixture screws in, it runs worse and stalls. I'm sure the timing is off now because just before it stalls, I get a back knock now. I'll take anything you got. I'm beginning to think I have valve issues fron the car sitting so long, not being started.

911pcars · 10-02-2002, 04:56 PM

Have you checked the accelerator pump on the carb? If it's squirting fuel at idle (check this with engine OFF), you should have enough to keep it going. Still, you may have some issues with fuel pump pressure/volume and idle circuits.

Do you have an aftermarket-big pressure pump or a factory type? If it's factory, yank the inline pressure regulator. You don't need it. My new one was faulty too.

To start and idle, all you need is a little of each: Fuel, Air, Spark.

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

Allenk · 10-03-2002, 04:32 AM

I rebuilt the accelerator pumps and they seem to squirt fine(right when throttle is given). I can keep the car running with these but that's the only way. The fuel pump is aftermarket and was installed by PO. I don't know its output pressure which is why I added the regulator. Previous responses mentioned the needle valve could be easily overwhelmed with too much pressure. Any checks that can be done on the idle circuits with carbs off?

Allenk · 10-03-2002, 08:21 AM

The thing is, if I up the idle, the problem is worse, ie.. it stalls out quicker. I know common sense says that there is a clog in the idle circuit, but if there is, I can't find it. I've squirt cleaner in every orafice I can find. The carbs are definitely sucking air when I give throttle, but at the same time, the exhaust stinks of richness.

911pcars · 10-03-2002, 09:27 AM

["....but at the same time, the exhaust stinks of richness."[/b]

Any particular spark plug (cylinder) wet with fuel or all? This indicates the engine has too much fuel rather than not enough. With the engine idling (as best as it can), carefully look down the carb. throats. There should be no fuel spilling into the throat from the discharge tube. If so, the float level is too high (per Tyson's suggestion), the fuel pump pressure is too high or one of the needle valves isn't closing.

It might help the baseline if you measure the fuel pump pressure, with and without the FP regulator. Try the above, then let us know.

Sherwood

Allenk · 10-03-2002, 04:23 PM

Will check,it'll be a couple of days since I have the carbs apart again.