[308] 308 won't run properly

[ari666]

unless there is an oil leak, plugs fouling is caused by too much fuel.

 

[DANNY8]

Got new plugs 2day. Looked in the book and carby plugs are rated at 5 for the heat range, where EFI plugs are 6 (slightly colder). So bought more EFI plugs, but higher heat range to match the carby heat range. Also changed the dizzy over to one off our other 308 with we know works fine. Started it up and still the same......and now the new plugs are fouled as well.

Yeah the coil is new (EFI coil, to match the leads and plugs), but gonna try the one off our other motor on it now when I go back outside.

Also gonna give it a compression test....just to check and eliminate that. There's bugger all blow-by (there's only a very small amount of pressure coming out of the PCV valves, no smoke either, so it's prolly not even blow-by) so the rings (which are new, and the bores were honed) should be fine. The heads come off a running injected motor, which was running fine. Only thing I've done to them since is gave the valves a cleanup with some paste, changed to LT1 springs and put new valve stem seals on them. So the valves should still be good.

Tested the leads with the timing light and they all seem ok....just bought a new multimeter so will go check them with that now.

I'm using a cheap ass silverline electric pump under the rear. Got a pressure gauge up front and it only gets to about 3.5psi, sometimes lower.....but that seems low so don't think it would be forcing the fuel in....that sound right?

Got another 600 Holley which I could try, but I haven't set it up since I rebuilt it...and not sure how. The 600 Holley which we have on their at the moment was jetted up 2 sizes I rekon when we had it on the dyno coz it was a bit lean for the motor....but this motor should be making a bit more power then the motor the carby come off so don't think that should be anything to worry about.

I've also got a vacuum gauge which I'll put on there and see if that shows anything up.

 

[DANNY8]

unless there is an oil leak, plugs fouling is caused by too much fuel.

Which could be caused by not enough spark to ignite the fuel hey?

 

[DANNY8]

Well I think we've found the problem. Took the fuse out for the fuel pump and let it run off wat was in the bowl and it runs farkin schweeet, no where near as loud as it was!! So a fuel regulator should do the trick hey? How much pressure should it be set too? Gonna go chuck the brake clamps on the fuel hose and see if we can get it running sweet with the pump on. If all goes well we might be able to still take it to the exhaust joint 2morrow and get the exhaust done....was hoping to have a few more k's on it (motor and car lol) b4 a road trip tho lol.

 

[ari666]

7 psi will fix ya up good stuff.

edit* so it wasnt an ignition thing then?

 

[ari666]

Which could be caused by not enough spark to ignite the fuel hey?

no. no chance. spark doesnt clean the plugs, heat does. thats why you have higher and lower heat ranges. 6 for gas, 5 for petrol. if we put 6's in our 308 it doesnt get hot enough to burn off the carbon and they get gunked up, if you put 5's in (on LPG) your asking for introduced-preignition cos they can begin to work like a glow plug in a diesel.

only two ways of 'gunking' up a plug if its the correct heat range is a. oil leaking into the cylinder or b. too much fuel and running rich. even still the blackest of black plugs will still work, itll take 5 seconds to burn that crap off.

if you were not getting enough spark to fire the fuel it wouldnt run. period.

 

[VS_UTE_S3]

Hi mate. Has been a while since I played with a 308 but I put a blue into my HQ Ute a few years back. I also put in a HEI Electric dizzy. I found the electric Dizzys need 12v to the coil so you have to run a relay off your existing 9v ballast wire. I originally tried to power my new electronic dizzy off the 9v wire and it ran like balls similar to yours. I couldn't even get enough power in the leads to drive my induction timing light. Also I found that the v8's have a false TDC. I used to put my No.1 cylinder to TDC using a screwdriver in the spark hole to feel the top of the piston, drop in the dizzy pointing at that lead then give it a try. If it didn't run right id put it back at that TDC then rotate the motor all the way around until No.1 cylinder was at TDC again then redo dizzy. You'll find that after rotating the engine 360 the dizzy will be pointing at No.7 or something. I think its to do with the exhaust and inlet strokes that's why there is two TDC's. I only have limited knowledge of such things but yeah that's my 2 cents. Good luck mate.