New to forum, 924 engine guidance help!!!

[Mexicoearly911]

Hello every one

I'm new to 924 and is my first post, I'm from Mexico City currently I'm restoring a 71 911 t sunroof, but is a no rush project [$$$]

Any way I just bougt a 77 924 with 42k miles that was stored for 20 years in excelent shape. I have always liked 924 and I would like to use it as my daly car.

The car starts very well, 3 or 4 minutes later it seams that it looses one cylinder.

If you turn it off and start it again it starts well again and 3 or 4 minutes later it losses a cylinder again, it lacks of power but keeps running.

Any idea of how to correct it or wich part is failing?? in order to buy spare parts

Help would be appreciated

[BryanM]

fairly new to these cars myself, but i would check the spark plug,spark plug wire, and distributor cap to start. if that checks out ok, maybe there is some type of obstruction in the fuel line or injector.

[alan6272]

fuel pressure??

[kmakovac]

it seems to be a duel pressure problem or worm up regulator problem,
possibly when the car warm up the mixture is to lean possibly in one injector.

Try to put out the injection wires from every cilinder to find the wrong one.

Then try to change the injector,sprark plug and other stuff and wait if onother cilinder go bad,then you find easy the problem in one conponent.

if the problem persist in the same cylinder can be a ditributor fuel or injection problem and must look closer this compononts.

[ideola]

Start with spark because it is easier and safer to diagnose than fuel. Get a spark tester. Remove the fuel pump relay. Check the spark at the main coil wire first. Then check each plug wire individually. If you have good blue spark at each of the wires, then pull each of the spark plugs and inspect the electrode. Make sure they are gapped properly. Make sure they all have a nice carmel brown color to them. If any of them are dry and black, wet and black, or dry and white, then follow the diagnostics in Haynes to determine what the issue is.

You can also determine which cylinder is mis-firing by starting the car, waiting for the miss to develop, and then remove one plug wire at a time from the distributor cap. If the car stumbles when you remove a lead, then that cylinder is good. If it doesn't, you've found your problem cylinder and can diagnose further.

If the problem is not with spark, then follow the procedure in Haynes for diagnosing the flow of the injectors.

[Mexicoearly911]

Thanks everybody, that will give me a point to start

Thanks again, i will post the follow trough

[Grandad#3]

Hello, You might want to check out the link below for more information on the 924.

924Board.org :: Index

Cheers,
Larry