Re: Mercruiser 1997 5.7 Weak Spark
I rechecked all cables and connections. Cleaned. I am at the point of purchasing new ignition system. I found one here 5.7L GM Delco Voyager EST marine electronic distributor kit. Would this make it work better? Thanks
Hello Marcel,
No, that is a fixed advance curve ignition system and not a very good one at that. You have a Thunderbolt V system, one of the best ignition systems available. The Delco system will not allow the timing to advance, in response to engine load and fuel quailty, to get the most power and best efficiency from your engine. Nor will it retard the timing, in the event of fuel knock/detonation, to prevent engine damage. You would also need to do some serious wiring changes to get the shift interrupt system to work properly. I know the literature says it is a direct replacement, but they don't tell you that there is a few hours of re-wiring to do.... All you need to do is take a step back and start to look at things a little differently.
I would do the following. (start at the beginning again). The first thing I would do is put all the original parts back on. I would then do a compression test to confirm it's not a mechanical problem.
Do you have a proper spark gap tester? If you do, hook it directly to the coil and check the spark quailty there. (I did ask you to do this earlier but got no answer, so assume you haven't done that yet)... If you don't have a spark gap tester, just get an old spark plug and open it up to about 5 mm (1/4") and use that. Make sure it's on the engine block properly and use that. Also make sure the distributor is propely grounded, as is the coil....
Then run though the TB-V troubleshooting chart again, each step in the right order and exactly as the chart says.... If you'd like, please post the result of each step here...
Just be aware that if the problem is not the ignition system, buying a new Delco system will not fix the 'no start' problem.
Let's do some proper and logical troubleshooting before you spend heaps of money that may or may not fix the problem. I have always found that approaching a fault and fixing it properly, as opposed to just throwing parts at it until it goes away, is the quickest and most cost effective way to get back on the water again...
Looking forward to helping you get this problem sovled...
Chris..........
(I will be travelling back home and therefore unable to respond between Sunday night and Monday night. So just hang tight, I
WILL get back to you.)
Thank you for your warm welcome ;-)
