Aussie944S

Guys,

a few months ago i bought a bad performanmce chip from a dodgy place that caused my car to not turn over and on installing the old chip the car began to hunt for idle.

Cut a long story short i got russell from MaxHpKit to hook me up with a new DME and chip and had my OLD dme fixed.

Both DME's cause the car to hunt for idle still sad face, Russell thinks it was my ICV or that i buggered the DME cable up but i have checked the cable and plug it looks good and nothing is worn or broken.

So with the car on i pulled the plug from the ICV and it still hunted for idle????

So i plugged it back in and pulled the plug off the TPS car stopped hunting for idle but the the idle rose to 2500rpm very slowly(as it got warm)??????

So i pulled the plug on the ICV and it shot up to almost redline so i plugged it back in?????

So i turned the AC on and the idle dropped to about 1800rpms?????

So then i turned the car off pulled the Air line to the ICV and sprayed carb cleaner in it plugged it back up and plugged in the TPS car still hunts for idle?????

I have done all the shop tests with my mutlimeter and everything is within range except the WOT test making me think its the TPS. Also smoke tested and dishwash liquid all vacume lines for airleaks couldnt find any.

I have also searched the crap out of google and every porsche forum for hints or tips.

Guys if you could give me a hand would be nice, i dont want this one to beat me yet and have to give it to the professionals.

thanks lads.

John_AZ

EDIT: just read your post over on Pelican- http://forums.pelicanparts.com/porsc...ml#post6677902

Looks like you have done a lot already.

GL

Just a couple of suggestions I found for your '88 944S.
You might have found this post...

https://rennlist.com/forums/924-931-...esitation.html

I have the '87 944S DME Test Plan that has a troubleshooting guide as well---slightly different from the WSM. See below.

You might have to take it to a shop that can decode the problem with the diagnostic tester (9268).

GL
John

Aussie944S

John_AZ,

cheers mate been spending most of my time realy just sitting in the car in the garage talking to it.... (haha weirdo)

When i have been given advice i have given it a whirl, thanks for the other post kinda sums up to me that i need to just get it to a shop t o diagnose the thing properly but obviously i want this to only be my last option.

i have a couple more weeks before i go away for a while so if i can search and get advice each day or two on what else could be the deal would be good.

not sure if i should mention that it smells a little like fuel from the exhuast, but testing the temp sensor from the DME with a multimeter it was within the Ohms range in the manual?????

how would one test for fuel richness?????????????

catamax944

Try one more thing with the ICV ,i also did everything you did and it didn't work. My ICV was brand new and malfunctioning.
With the car runing disconnect the air hose that goes to the ICV from under the intake boot and block both ends with your fingers ,see if the idle stabilizes. That will bipass the ICV completelly.

Aussie944S

catamax944,

cool thanks, i'll have to study the names of more parts before i do it but i think i may have pulled this hose off to spray carb cleaner in it.

Dunno

anyway thanks for the help i'll give it a whirl.

catamax944

Carb cleaner wont do it . I had to take my old ICV off and cleaned it with petrol in order to work but it only lasted a year or so. I got the new one a few months ago and it was malfunctioning from new ,took me a month and changed all the intake gaskets before i figured it out.
Yours might be a different problem but before ruling the ICV out it's better to check it properly,could save you some headaches.

Aussie944S

Cheers mate,

i'm gunna save my coin and buy heaps of parts and just replace everything when i get back from being away for work.

Question on a level of 1 (easy) to 10 (hard)
how hard is taking the manafould???? i think its called off to get to the ICV.

i did my own waterpump and belts a week after i got the car and thought that was about a 3 out of 10 to give you a rough idea on my non mechanical skill level.

Cheers Lads

John_AZ

Well If level 1 is checking the oil, removing the intake is maybe a level 3.

It becomes a level 4 1/2 when you do all the WYAIT (while you are in there) tasks.

You should replace the AOS seals (black oil fill tube to engine).
The intake has to come off to get to the 2 seals.

Then you can get new clamps, vacuum hoses, new rubber ICV mounts if yours are cracked, check the sensor gap, replace the heater control valve, rebuild the throttle body and send out the injectors to be cleaned, tested, and resealed.

Your car is 25 years old, check the fuel hoses to the fuel rail for cracking and moisture at the hose collars. No need for a BBQ later.

Minor stuff--just adds a couple hours/days to the job.

GL
John

Aussie944S

Cheers John_AZ,

seems like i could give this a good crack, just need to look at the parts manual to buy everything that is attacthed or plugged or around the manifold as you mentioned....

also what do you mean by clean and reseal injectors???? dont ya just buy new ones????

John_AZ

I have 8 used injectors on the shelf for the 924S. Spares I keep. I get my seals and the filter screens on eBay-8 sets for less than $20 US$

One of most often suggested companies is www.witchhunter.com to send your injectors to be cleaned, tested and resealed. The term "rebuilt" is not possible. Injectors are cleaned inside and out , then tested for the spray pattern and leakage and if they pass they are resealed. If they pass, the "OK" injectors are matched with "conditioned" spares if needed, to give you the best spray pattern.

Yes you can go out and buy 4 new Bosch injectors or have yours tested and matched to perform like new.

Many DIYs on injectors on the web.

GL
John

gtroth

Not a particularly tough job to pull the intake. On the 'S' definitely pull and replace the whole intake assembly in one piece, like I show here:

https://rennlist.com/forums/924-931-...on-x-post.html

Once that's off there's lots a can be done in addition to servicing or replacing the ISV, particularly for the S:
1. New gasket
2. Witchhunter the injectors
3. Replace the TPS and rebuild the throttle (on the S you can't really do these with the intake on)
4. Clean both grounds at the back of the engine (very important since on the S you can't access these with the intake on)
5. R&R all the vacuum lines and vacuum connectors under there. Good time to buy an Oetiker tool if you are a purist. Or just use hose clamps.
6. Maybe adjust the speed/reference sender (blocked from access by the throttle on the S)

Good luck.

Aussie944S

Awesome i'll make sure i do that,

I have to be away for a while with work so if i can try and keep off the booze while i'm away i might have the coin to get the parts and then take a week of work and fidle like a teenage boy finding his old man hidden mag collection.

Also i was in the autoparts store and this dude infront of me bought a product called liquid gasket or something......

Can we use that stuff on our cars????????