nine64

ken,
wow! you know your fuel stuff! the car is originated from England. I am not sleeping until i know what's wrong with my car and how to fix it!
so it could be the fuel quality then?
Fred,
all ground wire have been redone. actually that is the first thing my mech did.

thanks

Ken D

It very well could be a fuel quality issue, though I'm no expert on such matters. It's also possible that the valves have some carbon buildup or other deposits which is raising the compression ratio and causing detonation. You can try running detergents/additives like Techron, Ventil Sauber, etc to see if that helps, in addition to using 95 RON.

nine64

ok.. i give up. if anybody else have any other ideas, i am all ears here.
good night

nine64

hi,
i will be needing these as well
fuel tank sending unit
oil pressure sending unit
Coolant Temperature Sending Unit

any recommendation where to get them? new or used? how much should i pay?
cheers

hoffman912

gorgous car, congrats! just some friendly advice -that is an extremely rare car. i highly recomend that you try to keep it as stock as possable. the more you change and modify the more the value will decrease. this includes stuff like boost gauges etc. if its 100% reversable thats one thing, but if its not, dont do it, unless you have to. also if you take any original parts off, keep them, especially nla parts.

MartinT

I am certain this is a fuel issue.
When I lived in the UK, and had an early N/A, I rang PCGB (if memory serves) (PCGB = Porsche Club Great Britain). They recomended using super unleaded in my 944 N/A.
Super unleaded is RON 97. Of the various suppliers Shell's Optimax is RON 98.
This is what I used (occasionaly mixing in some lower octane rated fuel when I couldn't find the good stuff).

Is RON 97 or 98 available in Thailand?
I know Rennlist has a heavy US presence, while the CGT never made it over here (correct me if I am wrong). You might find some information from the UK guys and gals, TIPEC (The Independant Porsche Enthusiasts club) have a forum too.

Hope that helps

nine64

Harry,
thank for the advice, that is the plan! To keep it as stock as possible but also can be used. the past owner have it sitting in the air con garage for 3 years, so i am slowly bringing it back to life. For the boost gauge it will replace the clock and should be easily reversable.

Martin,
sadly there is no Ron 97 or 98 available. only 95
thanks for your help.

Superluminal

Disclaimer: I have only theoretical experience with the following, but have no reason to believe it will cause damage to your engine when performed properly (not exceeding 10% toluene). I'm also unaware of its legality in your country.

If you want to boost octane, you might want to try mixing toluene in with your RON 95 gasoline to boost octane ratings. Tolulene has an R+M/2 value (AKI) of 114 and is relatively inexpensive at $2.50/gallon.

RON is roughly (R+M/2) + 5. Toluene, therefore has a RON value of roughly 119.

Examples of various ratios:

10% toluene (RON 119) / 90% gasoline (RON 95) = 97.4 RON
20% toluene (RON 119) / 80% gasoline (RON 95) = 99.8 RON

Using a mixture of 20% toluene and 80% RON 95 gasoline should give you the 100 RON you are looking for, but that may be too high a concentration of aromatics in your fuel. I wouldn't exceed 10% or so...

If you have a (I think) 24 gallon tank, it should cost (in U.S. dollars) roughly $3.65 worth of toluene to make one tank of 97.4 RON.

More information is available here: http://www.elektro.com/~audi/audi/toluene.html

86 951 Driver

If the N/A Porsches are supposed to use Premium wouldn't you think a turbo 924 would require it as well. I say just run Premium gas and it will be ok. It is made for it. I imagine that it doesn't have a knock sensor so basically if you run low octane gas like you want to do then you have pull back the timing back yourself. I dont know what octane 95 RON but if it is the equalvailant to 93 octane here then just fill up with that stuff and call it a day.

Ken D

From my earlier post, 95 RON is equivalent to 90-91 octane US (RON + MON/2 method). He is not pinging on 95 RON, so he will be ok running this (though it is possible that detonation is occuring but isn't heard). If he wants to run higher octane he can fill up at the track (where he ran 100 octane), or try the toulene/xylene mix. Toulene is scary stuff though (check the MSDS on it) so I probably wouldn't use it on an ongoing basis.

Steve PH

It would be good if there was a proper world standard for Gas/Petrol fuel ratings! British spec early 944s are only supposed to run on 97-98 ron petrol but if you retard the ignition they will happily run on 94-95 without pinging (or pinking as we refer to it over here, no its not a gay thing!) .

It sounds like the mechanic you have used has successfully set the car up to run on 95, unless this type of fuel is incredibly rare/expensive I would leave it how it is. You do not want a weak mixture in a turbo engine!

Chris_924s

NO WONDER my old TR3 ran like crap on American fuel..
Thank for the great info!

pez

Hi Tennster

found this thread from a link on the 924board.....

I picked up my CGT 3 months ago; I live in HK & it had been sitting in a garage over here for quite a while !

Definitely sounds like a fuel issue, but I would add a boost guage asap to see what you are pushing.. I hit about .70 bar (CGT should push about .70 -.75 bar). I know guys that owns CGT's & have increased the boost a bit but they are running good quality fuel.

If your car is boosting too high this could contribute to the pinging especially if the few quality is poor in Thailand.

Also, knowing how the climate our side of the world eats rubber and the fact your car has been sat a while please tell me you replaced the timing belt

Re: parts - In all honesty alot of the consumable bits are 924 based, but I have used porscheshop.co.uk and pelicanparts.com to source bits !

Drop a PM on the 924board & we can swap info !

cheers !