Harvey928

I need some sound advice from all my fellow 928'ers.

I am scheduled to go to SITM this weekend, but my baby is not running good yet. I purchased it earlier this year with a bad / rough idle at best. I got it home and proceeded to do some work thanks to Dwayne and many other people's post on here. I have replaced numerous parts, knock sensors, hall sender, idle control valve, wiring & hoses, belts, timing belt is okay, just had to retension it. New plus, wires, & distributor cap.

I checked for vacuum leaks today, and following Dwaynes post i found the black hose, and it holds vacuum. But when I turn the engine on I lose all vacuum and when I try to pump it up it will not hold anything. I am guessing I need new vacuum diaphragms. It will not hold an idle, but if I can get it going it runs fair.

My question is whether I should try and limp this puppy up to SITM, or have it towed and rely on the generousity of others to help me get it running. I live about 140 miles from Spruce Pines. Any suggestions?

Thanks

Harvey

fraggle

140miles? Cap off the lines to the dash, zip tie the heater valve and go!!

Jadz928

Fraggle is right. Check the main vacuum feed line at the firewall where it goes into the cabin. If not holding vacuum block off. OR find out which diaphrams are leaking by checking them idividually at the solenoid manifold behind the center console.

White Lightnin'

Another NC owner!

If you can get it there, you will find lots of folks with the knowledge (and parts) to fix her up!

Welcome to the shark tank!

WallyP

It is not too likely that HVAC vacuum leaks will totally kill the idle...

For a two-minute test, look at the brake booster and find the small black/blue vacuum check valve at the top rear of the booster. Disconnect and plug the line from the booster to the check valve - this totally removes the HVAC vacuum system from the situation. See if it now idles.

Then use a small 4' rubber or plastic hose stuck in your best ear as a probe to find the hiss of a vacuum leak on or around the throttle body.

Harvey928

Wally,

I removed the hose to the booster, and now when I try and start the car it fires but immediately stalls (almost like not enough gas is getting to the engine). Could this be an intermittent issue with a fuel pump?

Harvey

SQLGuy

Did you plug the port at the manifold? If you disconnected that hose, you have to plug the port or, at best, the engine's going to run really badly.

Harvey928

Yes I plugged both the line from the booster and the booster

WallyP

The line that you were supposed to remove was the very small line from the booster fitting to the black/blue check valve.

In either case, your problem is almost certainly a vacuum leak to the booster nor the HVAC.

Do the "listen with a hose" test.

Harvey928

I tried both ways. I found part of the issue, the cable had come loose from the underside of the intake manifold. I made sure that this time it had the familiar pop when seated correctly. Right now I have the black hose coming from the interior capped, and the lead into the blue / black check value is also capped. It runs a bit better, enough to make it up to SITM.

Dave suggested I have a hand help me (wife was going to but family issue prevented her from helping). He suggested get the car running, and then spray water near the intake manifold to see if I can isolate the vacuum leak. I may try this tomorrow evening if I can get help, if not hopefully I can find a volunteer to assist in finding the leak and fixing it.

Thanks everyone for the information and assistance so far. I am proud to say that this forum is a very useful place, and the people here are the absolute best.

Thanks from the bottom of my heart.

Harvey

Harvey928

update I found that oil is seeping out of the drivers side exhaust manifold. I am enclosing a pic. Will I still be able to drive this to SITM. I know it is only 140 miles, but I am worried that the oil will catch fire. Any help will be much appreciated. I dont want this baby to go up in flames.

Thanks

Harvey

DR

That is coming from the Cam Covers, it is very "normal" for most 928s.. BUT, only you can make the call about being safe... BUT, the small amount that leaks from there typically burns off fast and i don't recall of ever hearing about a 928 Fire related to that...Auto Tranny fluid yes, oil leaks from cam cover, no.

If you decide to drive it up (FWIW, I wouldn' hesitate because of that) just tak it easy and keep the revs below 4000rpm..if you can :-)

Harvey928

Can you bring the rubber grommets (13) . I have the cam cover gasket already. I did not do the drivers side, but most likely will when I get up there.

I cannot thank you enough.

Harvey

blown 87

Get the sealing rings also, they add extra pressure on the grommets to help them not leak.
I use them all all the bolts, for some reason Porsche leaves a couple of them missing.

Harvey928

I will get the sealing rings as well.

I will be heading out around 3pm today and should be up there around 5:30pm barring any breakdowns.

Harvey