Issues & question on my 308GT4

Hi there,

Have a few questions below if you guys can help on my 1979 308GT4:
- I use 95 unleaded fuel. Is this the right grade of fuel to use?
- Whats the best grade of engine & gearbox oil to use for this car. I live in a very hot & humid climate(Malaysia)
- Plugs to use?
- Car backfires when i turn off the engine. Any reason why? Out of tune?
- Has anyone modified their power window to fit a more modern motor & mechanism?
- where is the best place to source for parts

Thanks for your help & look forward to your replies.

Cheers,
Mohan

 

95 is ok.
Check timing for back fire. Then check carb function and settings.
Window motors use power to windows to trigger separate relay. The connect relay to window and power from battery to get windows to move at best speed. Also clean tracks and ensure free movement. Oils use correct weight and api rating. Different gear oils can affect shifts positively and negatively. Lots like redline and Mobil 1

 

Thanks for all the information.
With regards to the window relays, I assume these are located near the fusebox? Pardon my ignorance. I was actually thinking of getting a japanese motor to replace the current one.
Cheers

 

Motors could be a problem but often it is just clean power to the windows. That's why using the stock power wire to the window and adding a relay to direct clean power to motors work well to get some speed. You can test the benefit by putting a fully charged 12.5v car battery on the window and see if that improves speed. If yes then adding external relay will too.

 

Are you in the US? Are you finding 95-octane fuel easily? I've only seen pump 93 being common in the Midwest states.
List of U.S. states by standard octane ratings - Wikipedia

 

"I live in a very hot & humid climate(Malaysia)"

 

I believe the OP lives in a country that uses the RON octane rating system -- not the AKI rating system used in the US. 95 RON fuel is about 90 AKI fuel in the US (so nothing too special).

 

No mate. I live in Malaysia. 95 is available everywhere here.

 

Oops! Missed that.

 

Octane rating - Wikipedia

According to this article, looks like the RON octane rating alone is used as Steve mentioned, so the octane rating as we're used to it, is lower.

I haven't had too many issues with 308's knocking. I only run AKI 91 which would roughly translate to 96 RON.

 

Once I've seen a carb 308 backfire badly on shutdown. The driver revved up the engine to 3-4K rev's and switched off the ignition.