Peckster

So I finally know why my car had a bad idle at start up that quickly went away. At first I thought it was a bad spark. Turns out the head gasket was slowly leaking coolant into number 4. That fouled the plug until the engine burned it off.

Questions, is 15 psi too much? Would a copper gasket be a good idea? That's what my mech wants to install.

Mike S

Copper headgaskets used to require retorquing every so many miles. You might want to talk to Dan at guru racing. He has a fully metal head gasket. I bought one and installed it on my turbo and haven't had any complaints so far. However, I've only covered 3k miles at most.

You could also consider a wide fire ring head gasket. Similar price, with a wider fire ring on the gasket. I would personally steer clear of the copper.

Jason_86_951

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Peckster:
<strong>
Questions, is 15 psi too much? Would a copper gasket be a good idea? That's what my mech wants to install.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">It's not the pressure that causes problems, its the lack of fuel that gets you. What chips/fuel managment system are you running?

Peckster

Autothority chips and an lbe. Which would be the main problem with running lean?

I was hoping for a vacuum leak, not a head job. To look on the bright side, this is a good opportunity to rebuild the head.

Jason_86_951

The Autothority chips run a little lean in the upper rmp's, combine that with low fuel pressure or clogged injectors and that might have caused it. I would reccomend after the head job to get your injectors serviced and upgrade to Guru chips.
Good luck!!!!

Peckster

Thanks for the suggestions, injectors were cleaned last year, although I was worrying about mixture. What's the gauge that monitors the mixture? Sources?

toddk911

get GURU chips and/or air fuel guage. or dyno with wideband.

Peckster

Got the car back and it runs great again. I had to screw the LBE in a few turns to get back to the pressure I was running before, I think the spring might be weakening.

As for running lean, I was concerned I might still be running lean and that that could cause greater problems if I installed a copper gasket.

My mechanic, who really knows 951s, said he wasn't aware of lean run problems with the autothority chips. To make sure, he temporarily installed an exhaust gas analyser from his race car, and found there were no lean problems throughout the rev range, so that's good news. He also said there's no need to retorque a copper gasket.

Danno

No need to retorque copper-headgasket, but you must use the correct sealant when installing.