4.3GL Timing

[DFE]

My 2000 Volvo Penta 4.3GL backfires at 2400 RPM but only at 2400RPM. The timing has been adjusted over and over and it won't stop. Any ideas?
DFE

 

[Technologic80]

Re: 4.3GL Timing

Confirm fuel pressure & ignition. Just because it is backfiring at 2400RPM does not mean the timing needs to be adjusted! The pickup coil, ignition module, fuel pump, fuel quality, and carburetor are all suspects that need to be individually tested and ruled out.

 

[Don S]

Re: 4.3GL Timing

The timing has been adjusted over and over and it won't stop.

Was it adjusted properly? Using the shunt? Might want to read this on setting timing on Volvo's using the EST distributor. http://forums.iboats.com/showthread.php?t=271407

 

[bruceb58]

Re: 4.3GL Timing

Don, could his problem be the S.L.OW. system cutting in? Not sure the 4.3L has that or not.

 

[Don S]

Re: 4.3GL Timing

He has a Carbed engine, the SLOW system is only on EFI engines.

 

[Technologic80]

Re: 4.3GL Timing

Don, could his problem be the S.L.OW. system cutting in? Not sure the 4.3L has that or not.

I know I sound like a broken record lately, but I'd be testing the ignition module and coil. (its my new solution to everything) lol.

Really though, the ignition module has a lot to do with timing. Especially since its a HEI/EST Delco distributor.

 

[bruceb58]

Re: 4.3GL Timing

He has a Carbed engine, the SLOW system is only on EFI engines.

I have the slow on my carbed 7.4L but have a completely different distributor.

 

[Don S]

Re: 4.3GL Timing

I have the slow on my carbed 7.4L but have a completely different distributor.

You have the EEM. Sorry to hear that, hope it doesn't break on ya, parts are almost non existant for that ignition system. The LK models were also the last to use it.

After reading this in the first post,

The timing has been adjusted over and over and it won't stop.

I'm not sure if the timing is right or even close or how it's been set.
But until it has been set correctly, checked and verified, I sure wouldn't start taking anything apart to repair or replace.

I have no clue at this point what has been checked. It could be fuel, it could be ignition, it could be a vacuum leak, it could be mechanical (compression), impossible to say without more information and testing.

 

[bruceb58]

Re: 4.3GL Timing

You have the EEM. Sorry to hear that, hope it doesn't break on ya, parts are almost non existant for that ignition system. The LK models were also the last to use it.

Sorry for the hijack but glad I found this out.

I guess a Delco EST would be my best replacement.