John Speake

The MAF is so far out of spec that the puzzle is why the car was driving fine one day and then would hardly run the next.

Not a typical MAF fault - I'll open it up tomorrow to see if a better diagnosis is possible.

928Quest

I didn't see anyone mention this and I'm not sure of the 90 has the ignition protection relay, my 91 does. When activated the car will run on only four cylinders. My GT would do this intermittently for a few years, it became worse. I eventually removed it and replaced all of the electrolytic caps. It hasn't failed in years now. If your 90 has it you'll see it hanging below the FI and ignition computers. When the problem occurs look to see if a red or green led is activated in the relay. That will show which set of four cylinders is OFF. Determine if the relay is legitimately protecting or just failing as mine was.

Johnnycool

yep for the testing i have been doing i have bridged the ignition control module with the correct jumper relay block just to take it out of the picture :-)

thanks

J

Johnnycool

bit of history i found on the car - just looking thru rest of it to see if anything relevant seems lot of these bits have been repaced fairly recently ......... dunno if that helps - hope to get maf and lh back from john this week , also gonna replace maf connector as boot and few wires don't look great

Johnnycool

Mrmerlin

thats an expensive ICV

worf928

Exactly 166.6% over Porsche wholesale.

Especially gruesome since I have yet to encounter a failed S4+ ICV. Sticky? Sure. Dead? Nope.

Johnnycool

well luckily before my ownership ! so work done about 4k ago

SeanR

I'm more interested in how they changed the ICV in an hour.

worf928

Easy: just write it up and don't bother. Wonder if they even ordered an ICV?

Wouldn't be the first time or the 20th time we've seen paperwork for stuff that wasn't or couldn't have been done.

And since when do you need to "loosen the intake" to replace the dampener and regulator?

Mrmerlin

it would take me atleast 3 hours to swap out an ICV on a S4 not that I would be rushing,
but lots of preventative things have to happen so other issues are not created.

SeanR

Yea, when looking at that invoice I just shook my head and was glad to read the OP didn't pay for that work.

worf928

From the time it rolls into the bay until it rolls out?

SeanR

LOL, that's a minimum of 6 hours.

Captain_Slow

EDIT: The ICV thing already came up.