911 3.2 Idle/starting problems

[DannyBNH]

I've got a SC with a 3.2 and over the last week, it's starting to have problems starting and idling. Seems to be kind of intermittent... Some days it starts right up, sometimes doesn't want to start at all...When it starts, it tends to be a weak idle ( give a little gas and it will die ).

This morning I went to start it up and it was worse than usual. My compression gauge was pegged, other times it seems to be dancing all over the place, although the engine sounded pretty even. I got a serious backfire that sounded like a shotgun.

I'm new at this, and am just looking for a good place to start looking around. Anyone have any suggestions?

Thanks
Dan

[ausgezeichnet]

Dan,
What Model year is your 911? The last Model year for the SC was 1983 with a 3.0L motor. Model year 1984 was a change to the 3.2L Carrera.

[DannyBNH]

It's a 79 SC, but it's got a 86 3.2 carrera ( not quite stock )...

I just took it out for a ride and it seemed fine when warmed up, just a bear to get it to that point.

[vreference]

So the engine is running the Motronic fuel injection setup from the donor car?

[Nine9six]

Try doing a search...There are just so many possibilities, that until you start eliminating the variables, the laundry list will remain quite extensive.
How about some more background...Has anything changed? Did you perform any work on it lately? Have you eliminated the simple items such as cleaning and testing your Idle Control Valve (ICV)? I am not sure if you have a Warm Up Regulator (WUR) but that component also could be your issue.
Do some searching, reading, and variable elimination, and chime back in with a fix or if things are still a problem. I am assuming you are running the motronic system which is OEM for your 3.2. Is this correct?
HTH

[ausgezeichnet]

Before you start down any path make sure you have all the basics covered.
1. Good spark plugs
2. Good Spark Plug wires. Make sure they are seated properly.
3. Good rotor and distributor cap
4. Good gas
5. Clean air filter
6. Clean fuel filter

After the basics are covered go slow and make one change at time. Here a few tests

A simple check for any vacuum leaks is to remove the oil cap while the car is idling, if everything is OK the idle should drop when you remove the cap.

As suggested in the previous post also check the ICV (idle control valve) .

You might also want to try unplugging your O2 sensor to see if that makes a difference.

You might also want to replace the DME relay. Although this more associated with a car not starting

Check to see if the plug to the Air/Fuel mixture screw has been removed. This could mean the PO messed with the Air Fuel mixture.

If you use the search function you will find alot of additional detail information.

Keep us posted on what you find. I am sure I missed a few things that others will post. This forum is great.

Good luck.

[DannyBNH]

We did a vacuum check.. All is good there.. I'll be doing the fuel filter & checking the plugs this weekend...

The funny thing is, after I posted this thread... It's been running like a top....

thanks for the tips.....

[DannyBNH]

Just an update...

A vac hose that went to the brakes had a rip.. Replaced the hose and it seems a bit better...

Have to see how it acts over the next few weeks..

Thanks All