Ferrari Mailing List: Re: Same troubles are back for 308

[Doug & Terri (dnt]

Drat – that’s a bummer Michael.

 

OK – the GTSi has nearly the same system as the Porsche 911’s do from mid-1973 and finally to 1983.  Bosch CIS (constant injection system).  I will tell you story but I have no idea why it happened or the particulars.

 

Picture this – 1995, Porsche Parade in Oregon.  We are showing our full concours ’69 912 and while prep cleaning one of to be judges comes by and sees the fuse block.  Ah hah – better make sure you have the fuses in the right order with the correct amps.  Hmmmm, coming from a judge that means my stuff may not be correct.  So I check it out.  Sure enough I am missing a few of the correct yellow 2 amp and several white 8 amp fuses.  Well, fortunately I have a loaner car – our 1982 911 SC.  At the show, we drive both cars over to the site - I snatch what I need from the ’82 SC and place them in the fuse holder for the 912.  Judging comes up – sure enough off comes the fuse cover – “oh good – all correct” and they move on to other parts.  Concours over with – and since it is Portland Oregon – it starts to rain.  I replace the old fuses in the 912 and Terri is ready to drive off in the SC but without replacing the fuses.  It starts – it idles – any gas – it dies.  Huh?  Do it again.  Starts, idles, gas – dies.  $$&^%$&$#(?)  and of course it’s raining.  I reach in my pocket pull out the fuses I took from the car and replace them.  NOTHING else.  Start the SC – idles, give it gas – it revs up – its happy.  Why??  I always meant to go back and double check why this occurred.  Never found a wire diagram that would tell me THIS is the reason.

 

OK – story told – I am wondering if The Birdman http://www.birdman308.com/fusebox_upgrade.htm  is right.  I know there is a fuel pump fuse but what else on the CIS system is there that causes this?  Could this Ferrari set up be similar to the Porsche 914 fuel pump set up?  One relay opens the circuit to the fuel pump relay which runs the pump.  That’s right – TWO relays to run the pump.

 

Now on the 911 SC, picture this – you run out of fuel.  Bone dry.  Pump sucks air better than fuel.  Ignition switch runs fuel pump for a finite amount of time – a few seconds or so.  To get around that – go to the engine, remove the air filter cover and air filter, place your hand in the box and lift UP on the air flow sensor plate at the end of the balance beam until a squealing is heard.  That’s fuel passing thru the injectors – you now have a charged system.  No squeal – no fuel.

 

SO – here’s a patented CIS check off list.

 

·       Fuses all ok?

·       Fuel pump running?

·       Do almost the opposite of SC air filter above.  I believe the 308 GTSi requires the sensor plate be pushed DOWN to activate the fuel pump.

·       If I recall – you heard a loud backfire the last time – Ow.  To diagnose a blown air box - With engine idling – take a hose and gently place one end to your ear and with the other end skirt around the air box seals looking for sucking sounds.  If there are sucking sounds you blew your air box.  If so – as soon as you step on the gas the fuel mixture goes infinitely lean and engine stops.

·       Fuel filter clean or new?  A plugged fuel filter will let enough fuel though for idle but not much else.

·       Porsche’s have something called a warm up regulator.  They, of course, are NLA.  BUT they do go bad and shops have been able to monkey around with them and fix them – sort of.

·       And last but MOST important – the CIS runs on fuel pressures.  So - is the fuel pressure correct?  That’s a shop project.

 

That’s about it. But just to keep you happy – who says it’s a fuel delivery issue?  Could be a stuck EGR valve?  Could be a wacky dizzy that goes full advance and kills the spark?

 

I love cars –  Keep us posted Michael

DOUG