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Discussion Starter · #1 ·
My stage 1 9-3 lost performance a couple of months ago and the boost was changing wildly from one week to the next (with no change in power). I changed vac pipes, plugs, dump valve and had the car dyno tested to check the boost solenoid and actuator (and turbo internals). The DI cassette is only a few months old.

Yesterday, I started to get a misfire, but only at 0.5 bar and above. Following an excellent thread written by Bubbles in March ( DI overhaul) ) I found little or no evidence of grease in the DI sockets, and there were white deposits on the ends of them. I cleaned the DI sockets and repacked with silicon grease. Hey Presto
!! 50-75mph in 4.3 secs - that's over a second quicker than before!
 

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DI's cause all sorts of weird and not so wonderful symptoms with regard to running....but glad you have sorted yours. My lack of boost was attributed to a collapsed exhaust but not found until I had checked all the usual. I obtained some silicone grease from Radio Spares and re-grease the boots each time I renew the plugs.

Mike
 

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Took my DI out today (must have known the 4 bolts were lose again).
Had small amount of white deposits around end of nose (rubber part) and no evidence of 'grease' at all.

Ive read the threads but i'm unclear about re-greasing with silicone grease. Do you lightly smear around the nose and using your little finger the inside of each 'pot', or do you 'pack' it in nice and thick. If the latter, wont this mess up the connection between the tip of the plug and spring connector if they cant marry metal to metal??
Is it necessary to split the DI in half and clean internally?
I'm hoping this cleaning overhaul will help cure a faint and constant stutter in 3rd when I
 

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It's a thin smear with the little finger!

You may want to stretch the springs a bit as well, just to make sure they are in contact. I think they fall out if you take the rubber bits off.
 

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Ok, I'll use my index finger!
Seriously though, if you pack it right up to the tip of the spring (which is just visible) will this not have an effect on connectivity between this and the plug? Should you not have metal to metal contact?

Nice tip about stretching the spring a little.
Cheers
Paolo
 

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As stated by sgould just a smear(about as much as you would put on your toohtbrush ) although I cover the outside of the boots. It is only there to keep moisture away from the contacts with the plugs.

Mike
 

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I don't think you need to be too cautious with the grease, although don't go over the top! I used spray silicon grease on mine and that worked fine. The pressure of metal to metal contact is adequate to overcome any insulation offered by the (at that point) very thin film of grease that may be there. The purpose of the grease is to help make sure that moisture etc. is kept out and the spark doesn't start jumping down the side of the boot. I believe the main time the jump happens initially is on the burnoff; there's much higher voltgaes present there, which could form the initial carbon tracking that could then be followed by lower voltages.
 

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Discussion Starter · #9 ·
Not knowing any better (and desperate to get the car running properly!), I filled the bottom 15mm or so of the boot with grease and it has worked perfectly.
 
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