Starting After CIS/Induction Reinstalled

[usafa]

I finally have my 930 put back together. I had the CIS system, airflow meter/FD, and intake off. Replaced stock injector blocks w/new stock, everything else stock. Except I had to replace an aftermarket divider plate do-dad in the manifold (see earlier thread) because PO had one installed which came loose and was floating around in the manifold. I had one machined with wider base and larger bolts and installed with red threadlocker and lock washers to prevent same thing.

I did not burp the fuel system. I tried to start and it almost caught a couple of times early, but then would not catch at all. I can hear the CD unit whining, so I'm confident I probably have spark. I did have slight fuel smell after cranking for a mininute or two. Gave up for the night (last night).

Will I have to burp the fuel system? If so what is an easy way to do this now the thing is put back together. Are there any other tricks to get the thing started after having the CIS system apart like this? By the way, the car has been down about 6 wks.

Thanks for any feedback.

[pohsche]

I'm afraid you are going to have to burp it. I don't know what is like on a Turbo, but on my '77 Carrera 3.0 it is easy. All I have to do is take off the air box cover, remove the air filter, and reach in and lift the little arm in the back right corner of the air box. The key should be on and it only takes a few seconds or you end up flooding the beast. Good luck!

Alan Poh
'77 Carrera 3.0

[usafa]

Alan,

Thanks for the reply. I'll give it a shot this evening.

[usafa]

Ok, it still won't start. Here's my rooky story and hopefully someone will have some compasion and give me a pointer or two.

I attempted to bleed the fuel system. Here is what I did and what happened. I removed the air cleaner, unplugged the air sensor contact near the FD, then turned the ignition switch to the on position. I then pushed down the air sensor plate. There was some resistance and audible noise as I did this. I held it down for about 10 secs. I thought that was great and I ran around to try to start the car. It caught almost immediately, ran very low RPM for about 30 secs, then died. It would not start back up.

Then I realized I hadn't plugged the air sensor contact back up. Ooopps! I plugged it back up and tried her again. No joy.

THEN I REALIZED I had fuel dripping from the rear of the engine bay! (through the exhaust?) Man, I must have REALLY flooded the damn thing. I gave up for the night thinking, I just have to let the excess fuel evaporate so I wouldn't blow myself up.

I did attempt to bleed the fuel system again. Unplugged the air sensor contact and with the ignition in the on position, I pushed the air sensor plate down.......no resistance and no noise...did I break it by cranking the thing with the contact unplugged?

Tonight, I just tried to start with no luck, Then I tried the bleeding process with no positive indication during bleeding process and no joy when cranking. This time no fuel dripping though....I thought that was a good thing.

OK anyone have any idea if I really screwed something up? Could I have fouled the plugs? I haven't pulled any yet. Or could there be so much fuel in the cylinders, even sitting overnight that it just won't start?


Help????

[47silver]

replace the plugs with new and try again

[usafa]

So you think I fouled the plugs? Damn! They were brand new! Can they be cleaned?

[usafa]

Hic-up

[usafa]

I don't have much experience "reading" spark plugs, but I did pull three of them (they're only about 2 mos old) and they all had a black carbon coating over the electrode and contacts. I'm guessing this means it has been running rich? Or that I just fouled them after flooding the engine?

Any comments would be helpfull.

[RoninLB]

Originally posted by usafa
I don't have much experience "reading" spark plugs,

and I have no experience reading a 930.. but if it was my non-turbo 911 I would.. pull all the plugs, pull the Cd box connector, put in netural, turn the key to spin the eng for a few seconds, see if any fuel spit out, check that the plugs are decent. then reinstall everything, and try to start it.. if may start without touching the sensor plate.. after it starts and idles correctly shut it down and change the fuel contimated oil.. then do a fuel/CIS adjustment... then change to new plugs....

[usafa]

Thanks for the guidance Ron. If I understand you correctly, the fuel flooding could have made it into the oil/crankcase? I didn't think about that. Will give it a try.

[RoninLB]

Hey Brad.. I'm a weekend wrench and been faking it for a very long time, LOL.. but, don't fool with the sensor plate unless you have to, and I don't think you have to anymore .. if you have to, do it for 2 sec and try to start, then another 2 sec, etc .. fake it until you get the feel of the sensor plate act.. and there is probably enough fuel in your oil to read it on the stick..

[usafa]

Ron,

Now I'm damn glad you posted here. Again, I wouldn't have thought about fuel in the oil at all. I'm not sure what would happen with fuel in the oil, but I am sure it probably would be VERY $$$$$$! Sounds like you know about this situation from experience?

By the way, after bleeding the fuel system, do you normally reinstall the air intake/cleaner prior to starting? I have the Powerflow w/K&N Cone filter so the only two lines attached are I think breather hoses for the oil tank, ect. Any loss of vacuum with the air intake/cleaner off?

Thanks again

[RoninLB]

Originally posted by usafa
do you normally reinstall the air intake/cleaner prior to starting?

don't have to do it on a normal CIS.. but again, I know a little more than nothing about 930 CIS..
. and if you think the battery MAY be slightly discharged from previously trying to start it, give it a full recharge.. so the ignition system has no excuse for getting to work..

[usafa]

Ron,

Yeah, I have a trickle charger permanently attached so I'll just plug that in this morning and let her sit until this weekend.

And you, sir, need to get some sleep. Or are you like me, one of those who just need 2 or 3 hrs a nighzzzzzzzzzzzzzzzzzzzzzz....

[usafa]

Finally got 'er fired up and running today! Hot damn!!!

Ron, I did what you suggested yesterday: pulled the plugs (coated w/carbon but cleaned up well), spun the engine (no sign of fuel, but it had been several days since flooding), reinstalled the plugs and reassembled the induction system. You have to remove the intercooler and bypass valve body to get to the plugs on the left side (what a PIA). There's always that ONE vacumn hose you left off when everything is put back together!

Finished up Sat night and tried to start......nothing. So I decided to come down with hayfever and gave a rest overnight. Sunday morning, I pulled the fuel pump relays, and the air sensor switch delayed relay (in the engine compartment) and checked with a volt meter. I think my air sensor relay is weak because it rattles when shaken and I can get resistance between varying pins after shaking. Guess I'll replace that soon.

Anyway, I put all relays back in and tried it just for grins. I started, but didn't want to idle at first. Kept the pedal down to idle at around 1000 rpm until it decided to idle at around 300 rpm. It slowly increased speed with some surging to normal idle at around 900 rpm at operating temp.

Shut it down and changed the oil to get rid of fuel contaminated oil. I'm trying the Valvoline VR1 Racing (dino) oil 20W-50 this time around.

Started back up and backed her out of the garage for the first time in about 8 wks and let her warm up. Idle stabilized at around 1000 rpm and took off after adjusting oil level.

She ran fine and noticably quieter with the replacement bypass valve body which came off an '89 when on boost. My old bypass valve must have needed resealing. The only thing I noticed was the idle dropped periodically at stoplights, but bounced back to 1000.

I stopped and added some Techron (2 pints) and filled up the gas tank. After returning home, turning off, then restarting, the idle did not want to stabilized unless I gave it some gas to keep the revs up for a moment or two.

So, my problem seems to be uneven and low idle at cold and warm startup. I checked the auxiliary air regulator resistance which was 24 ohms. Is this too low as the spec is about 33 ohms? I pulled the hose off the AAR to observe the sliding plate. It seems that it closes off too much since when I pulled the plate open slightly, the idle rose and stabilized. Is this a common problem? The other possibility is maybe the car is running too rich?