Bad Luck with 308 GTB

Start with the basics. Is the problem ignition or fuel related?

 

If your exhaust has a "gassy" smell, meaning, the smell of raw fuel, you are not getting spark every where there should be.

Check to see if you have spark at all eight plugs first. You can do this with the fuse for the fuel pump pulled.

An outside possibility is a stuck float or floats (needle valves) in the carbs.

Pulling the plugs and finding them dark and wet would also indicate no spark. Start with the rear bank first.

 

The front bank is problematic to get the plug wire seated on the extender properly. Hopefully you have a plug or two not getting spark. Gas smell would seem to me a plug not firing, or flooding and fouling.

 

And fix it good before you run it or you will kill the cats and fail in 2 years not to mention raw fuel cylinder wash down etc.

 

You have a nice car, you should do the right thing by it. Fix it right.

1. Compression check
2. Ignition check
3. Spark plugs check
4. Wires check
5. Fuel level check
6. Dizzy check
7. Then rebuild your carbs

 

A 3" socket extension works. You just have to find the right angle to get it out, and a great flexible magnet pole for help to get the extension in range to get a hold of.

 

Another thought, if it was running fine when you parked it and sat and now it doesn't. Look over the wiring closely for any rodent damage.


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Eliminate good systems. Just because you have new parts doesnt mean they are good parts something could be bad.

 

don't get fooled by exhaust feel on your hand. one side does produce less pulse pressure. It has been decades since I owned a 308. Do proper diagnosis before you start part swapping. Also, my 79gts came with the swivel socket to change the plugs. Check your tool roll. Maybe my PO put it in there and I thought it was Ferrari issue? Back in my 308 days I seem to remember others having that tool too when I went to help them wrench on these cars.

 

I just slapped myself on the head.

 

I found that the tool supplied in the tool roll actually worked the best for me when removing the front bank plugs in lieu of my own tool build-ups.

I did it with the rear hatch on the car and reached down through the gap between the hatch and rear window.

A strong extendable magnet is recommended.

Piece of cake.

 

If you are sure it's the front bank I would zero in on the distributor for that bank for starters. It's very easy to check output without a lot of disassembly.

 

GearWrench 80547 13/16-Inch x 6-Inch Swivel Spark Plug Socket - Gearwrench Magnetic Swivel - Amazon.com

Tool roll plug wrench is nice but this is better as the magnet is built in. Verify size. I accidentally bought a 5/8th and smacked myself when it was too small...oh well, now I have two.

 

These cars can foul plugs real quick, especially if you run the car without heating the plugs fully up like moving it around the garage. Once one plug is fouled and the car left to idle the entire bank will start to stall out and turn black. I chased a phantom problem for about a month before I finally figured that out. I run NGK BP5ES at 024 gap. Others have their preferences.

I would swap out all the plugs (don't try and clean them) test compression at this time then fire it up and take it for spin without letting it idle. Once warm, give it an Italian tune up (drive it like hell!). A few WTO runs through the first 3-4 gears. Then take it back the garage without excessive idling or sitting in traffic and pull the plugs to see what they look like. If one or two look bad I would focus on those cylinders. Swap extenders, set air screw, etc. If they look good, then I would fire it up and see if it will idle for an extended time. If it doesn't then you have some sort of problem causing the plugs to misfire and foul at idle.

I would check timing first. It's a PITA compared to normal cars. Invest in a bright parts marker and make big lines on your flywheel or damper at TDC. If your idle timing is too far off on one bank, that may make for rough idling, misfires, then plug fouling. This could be the case because your timing was likely set at 5k RPM and idle timing left to be what it is. If your advance is not working well your idle timing could be way off. I think they recommended dizzy rebuilds and this may be why.

I would then check the points set up to make sure they are all good. Then I would check the resistance on the wires through the caps and the coil leads as well. I would also do an old school spark gap jump test to at plug extender to make sure both coils are supplying full spark at each plug.

Next I would suspect fuel. So I would make sure the air screw is not too rich/lean on any cylinder. After that I would suspect a carb air leak or fuel pressure. After, that, rebuild the carbs and replace the bearings which are prone to air leaks.

If that doesn't get you there then maybe a leak down test.

 

Needs plugs