'77 motor stops running....help

[papi]

I just got my 1977 911s targa back from the shop where the trani was rebuilt and the motor seals were replaced to prevent oil leaks. I also had fuel lines replaced.

My problem is the motor will die after being warmed up for no apparent reason (to me). I have had to push this car out of traffic several times. The solution is to let the car sit for about an hour and then it will start up. I am thinking this is a fuel related problem. Possibly the fuel pump. I am hoping that I can get some ideas on a solution from this board so I can avoid a mechanic replacing a lot of unnessesary parts as a way of trouble shooting the problem.

Any ideas would be greatly appreciated?

[poorsha]

Check the battery.

[papi]

Man you guys are awsome! Very quick responses!

Battery is strong. After it dies I can crank the engine over repeatedly for about a half hour.

I always warmup then engine for about 3 minutes before I take off. Today the motor died 5 minutes from my home. I was at a stop and put it in first and when I started to release the clutch it died. I cranked it over several times and it wouldn't start. I live down the street from Pelican Parts and had to push it out of a major boulevard. #%@&ing embarrasing. Luckly, there were a lot of Airforce police around to assist.

It seems to me that the car is flooded and that after sitting for awhile it will fireup. Hope this explanation helps.

[papi]

I neglected to mention that my airbox has one of the tabs broken, so I can not have a strap(left side) attached to hold it down. Is this a big deal? My mechanic has indicated that having only one strap should be good enough, but I am worried about a vaccum leak. The motor was out when they did the trani rebuild and I am somewhat peeved that they did not give me the option to replace the airbox then. Now that the engine is back in the car, I am told, that it is a pretty big deal to replace the airbox.

Is it possible to have a CIS fuel system flood?

[IROC]

Not really enough info to give you a good answer. Obviously, the engine is losing fuel pressure or spark when it dies. I would go through and check all of the obvious things first - loose wiring for starters. If they had your engine out to replace some seals, there might be something loose.

When it dies, take the air box cover off and - with the ignition key in the "on" position - gently lift up on the sensor beam under the fuel distributor. You should be able to hear and feel the fuel pressure going to the injectors. If you don't feel this, then you definitely have a fuel delivery problem. If you do have fuel pressure, check for spark...

Mike

[bigchillcar]

classic symptoms of a dirty fuel filter...starts fine then dies after driving a short while. at first, all the sediment is in the botom of the filter, but after driving, it gets stirred up and abruptly clogs...after sitting an hour it will clear and repeat process. how long has it been since this has been replaced?

so, when it dies, does it stumble or does it die very, very abruptly?

if you are only lacking a strap, why replace the whole airbox? an airbox isn't cheap, but a strap is...relatively speaking. i have known some to use string temporarily to secure in place of a broken strap.

if you have a vacuum leak, then the car is running lean. and, as a cis injected car warms up, the warmup regulator gradually leans it out even more as engine block temperature rises. it could just be that it can start wit the vacuum leak, but the process of leaning by this regulator as the engine warms eventually becomes too much and the car simply gets too starved for fuel.

so, i'm going to say fuel filter or vacuum leak from what you've described.
ryan

[wrx paul]

When I still had my 2.7 in my 77 I had a similar problem. As soon as the car warmed up it would die. Turned out to be the permatune box. I replaced it with a msd unit and it never happened again.

[bigchillcar]

When I still had my 2.7 in my 77 I had a similar problem. As soon as the car warmed up it would die. Turned out to be the permatune box. I replaced it with a msd unit and it never happened again.

hmmm...a possibility. more likely this would cause the 'more abrupt' dying i was asking about, as it's ignition related. do you know where your cdi box is located? in the rear on the driver's side...silverish, finned...roughly 4x4 inches in frontal area. it should have a high pitched whine when you turn the key to on. check it before you crank and also check for it after it's died...
ryan

[competentone]

Originally posted by bigchillcar
classic symptoms of a dirty fuel filter...starts fine then dies after driving a short while.

Classic symptom of a dirty air filter too--or a blockage in the intake system--did anybody "stuff a rag" in the intake while working on the motor and forgot to remove it?

[vash]

will it die if you just let it idle up to hot? i hope so, because you can just look for spark and listen for fuel when it does. i cant imagine a fuel filter getting that dirty! wow. i guess i am changing all of mine on time. i think the symptoms are still too vague. you have to look for fuel and spark when it dies. good luck.

[grant lyon]

"flooded" suggests you check your ignition for spark and look for obvious ignition problems. I used to have an intermittent distibutor wire problem -- intermittent open at the connector.