Joe6pack

I pulled the fuel injection this morning. I'll attach some gratuitous pics later. It looks like a six-legged spider sitting on my work bench. I am going to go ahead and clean everything up. Should look great.

Here is my true "flames in the rear view mirror" story - though it wasn't really flames. Before I bought the Porsche, I had a 1972 Pantera. I bought it off Craigslist needing paint and interior work and did a mechanical/cosmetic restoration on it. Anyway, the PO had installed an oil cooler where the A/C condensor used to be. It had two rubber oil lines running from an oil filter adapter on the side of the engine along the rear frame rails to the oil cooler. I was doing some work on the underside and pushed the oil lines up between the top of the rear frame rail and the driver's side short shaft. Then, I proceeded to forget what I had done. Later, I am driving to a tennis match when I look in the rear view mirror I see nothing but white smoke. I immediately shut her down and coasted into a daycare center parking lot. I just knew I had blown the engine or at least a head gasket. Turns out, I had rubbed a hole in one of the oil lines and had sprayed hot oil all over my somewhat detailed engine. What an idiot.

Joe6pack

Oh, and I guess I should add, that one of the intake gaskets was missing a small section, so no amount of tightening was going to fix the leak.

Joe6pack

Well, I did it. It took a couple of Saturdays because while I had everything apart, I decided to do some cleaning, but I now have new intake manifold gaskets and spacers all around. What a difference! It’s like a new car. The idle drop is gone.

I drove it to work yesterday and hadn’t really made any adjustments except to set the AFR screw at a baseline 1.5 turns out. I knew the idle was high. Last night when I got home, I adjusted the AFR using the oxygen sensor and the multi-meter. It was reading 0.9 mV and I adjusted it to 0.66 which is closer to 14.7 from my understanding. I also adjusted the idle which was way high. I drove it to work again today and I think the power is a little down from yesterday. In reading on Pelican, I found a chart that said around 0.875 mV is max power for normally aspirated cars, so I think I’m going to push it back up to 0.875 mV. It just seemed to rev easier and more smoothly.

At any rate, thanks to everyone for all their help. I guess I should have listened to everyone who said vacuum leak over and over again.

John

Ed Hughes

Great, thanks for updating!

rusnak

If the idle went high, then it could have gone rich. That would actually make sense if the idle screw was left alone and the vacuum leaks were eliminated.

Joe, I would beg, borrow or steal an LM-1 and do the baseline test w/out O2 sensor to set baseline mixture. Then do a lean stop and rich stop test to check that the dme feedback loop is working.

Don't forget----a old o2 sensor will send a weaker signal, fooling the system into richening the mixture. I have a graph somewhere, but you get the concept.

Lorenfb

"In reading on Pelican, I found a chart that said around 0.875 mV is max power for normally aspirated cars, so I think I’m going to push it back up to 0.875 mV. It just seemed to rev easier and more smoothly."

Remember, the adjustment screw only affects the target idle mixture,
i.e. It's only a very small hole that bypasses the AFM flapper. Also,
don't believe everything you read on Pelican. For the matter, believe
very little you read on Pelican, as most there are brain dead when
it comes to technical issues, i.e. They just repeat the mis-info others
have posted.

Dave Thomas

Oh yeah, guys like Grady Clay, Dave @ TRE, Chuck Moreland @ Elephant , Peter Zimmermann, Jack Olsen, what a bunch of losers.

Joe6pack

Well, crap. I enjoyed 3 glorious trouble free days commuting to work this week. So, I have the day off and I need to go to the post office. She starts right up and settles into a nice smooth idle. I back out of the garage and get to the end of the driveway and she just dies. I try to start her, but no go. She turns over, but no start. I immediately suspect the infamous DME relay. The wife helps me push her back into the garage. Turn the key, the relay clicks, but no fuel pump. I bypass the relay and the pump comes on. A new relay will be here next week. Sigh...........All these days off and no Porsche.

Dave Thomas

... Steve at Rennsport, John Walker, Bill Verburg...

Where are you located, Joe? I have a spare.

Joe6pack

Hi Dave - I'm in Braselton, north of Atlanta. Thanks for the offer, but we're snowed in anyway. My new one should be here Wednesday.

dshepp806

Why can't we get a group buy together,..at least in a similar geographic region (nearby)?????????? Guess it's time to price this baby........

Doyle

TroyN

Since you should always carry a spare DME relay, you mean you ordered 2 right?

Joe6pack

Well, Troy, it seems I will have a spare. The relay isn't the problem. I don't know what is. I popped in the new relay today (kudos to Pelican for fast shipping), but no go. I assumed it was the relay because when I bypassed it, the fuel pump ran. Tonight I ran the diagnostics on the relay (per the relayBentley manual. I have voltage where I am supposed to have voltage and ground where I am supposed to have ground, but the pump doesn't run. However, I am only gettin 5-7 volts on the relay terminals. I don't know if that's normal or not - the manual doesn't say. I guess I will check the pump tomorrow.

rusnak

What is the battery voltage, and have you cleaned the terminals and checked the battery ground? Re-check all the ground locations for the Motronic system identified in the Bentley manual, and clean the contacts with a brass brush until they are shiny, then re-tighten. Is the electrical switch loose? Have you tried to pull forward on the switch cylinder while turning the key?

Joe6pack

Thanks Russ as always. I made a boo boo earlier. I was getting 5-7 volts when using the door striker as ground. When using I switched to to a seat bolt I got 12 volts.

The battery has 12 volts. I cleaned all the grounds before when iI was chasing my idle issue. I will try pulling forward on the ignition switch tomorrow. I also verified spark with a timing light.

Thanks.