Mercruiser 5 7 vortec delco voyager est power issue

[SeaRaySalmon]

I have searched the internet and the forums and have not found the answer I am looking for.

I recently replaced the old TB IV ignition system with a delco voyager est. Engine is a mercruiser 5.7 vortec with 4 barrel holley carb and edelbrock intake. The boat ran great with the thunderbolt ignition and makes a ton of power but the module went and from what I searched online the delco voyager est was the best replacement.

Problem is the boat doesn't seem to have the power it used to. The only thing that has changed is the ignition system since the power loss. I set it to 8 degrees initial timing like the manual said (using the shunt and doing it correctly). I then tried 10 degrees initial timing to see if that would help and it didn't.

I have been using the boat and it's fine, I wakeboard on it and it runs well but this motor should make around 300 hp and it used to jump up on plane in seconds with the 4 blade prop and it just feels like a bit of a dog now..

Any ideas what the timing curve is on the delco voyager est module and what the timing curve of the TB IV module was? Anybody ever swap out the module on a delco voyager with a different curve? Where would I get a module with a different curve?

 

[alldodge]

TB4 to EST means it went from grounding the shift interrupter to applying 12V

Have not seen a TB4 and a vortec combo.

What is the motor serial number?

 

[Bondo]

Problem is the boat doesn't seem to have the power it used to.

Ayuh,...... Welcome Aboard,...... What's the time frame, from when it had power, to when ya think it don't,..??..??

 

[Scott06]

I thought the TB4 modules sasid V8- 22 or something like that the last two numbers were the advance amount. I think the Delco gets like 26 total degerees advance. I'd verify the total advance you ahve at 3k rpm if you are 26-30 total I would look elsewhere for loss of power.

 

[Scott Danforth]

unless you put a vortec headded block in place of your older SBC, they didnt put a TB-IV in a vortec motor.

non-vortec headed 350's made 260hp or less..

to get "around 300 hp" means that either its a custom built motor or its an MPI motor

so, lets start with what you have

 

[SeaRaySalmon]

So the engine was a crate small block from summit racing that we "marined". We put all of the boat stuff from the old mercruiser 5.7 that the boat came with (1990 sea ray bowrider 190) and that motor had the thunderbolt IV ignition. My buddy did the work he's a mechanical engineer and builds race cars from the ground up. We had and old 350 on it for years but it was a junkyard pull and eventually lost compression. So 3 years ago I bought the boat from him and we put the crate motor in it. Ran great always made good power. We put the delco voyager est in once the module went bad on the thunderbolt IV. That was about a month ago since then had the boat out twice and just doesn't feel as responsive at the throttle.

I guess I should have stated what the motor actually was when I posted lol. He knows way more about it than me and he told me we need to find out what the curve on the TB IV was because that worked very well with the motor. If we get that curve and figure out the current curve in the delco module we can compare and maybe change out the module with one that has the best curve for the motor.

 

[SeaRaySalmon]

also the "around 300 hp" was a figure he said this motor probably makes, I have never actually tested the hp on it.

 

[achris]

I hope you still have the old module and can verify the code on it, because the V8-22 was only used on 5 litre engines, never the 5.7. Early 5.7s did use a V8-22A, maybe that was it? You need to verify that. I have curves for both. When you know which one you have, I'll post it up...

Chris.....

 

[alldodge]

Your applying 12V to the distributor to set base timing?

If correct, with distributor not in base timing mode, see how much advance your getting

 

[SeaRaySalmon]

achris I am applying 12v using the shunt to set base timing. I have a little alligator clip and hook it to the battery. In the driveway when I rev it to check total timing it immediately jumps to 20 almost instantly and up 3k rpms seems like thats all it goes up to is 20 or maybe 22. But that is only in the driveway have not checked on the lake.

alldodge I'll have to check if my buddy still has the module and let you know thanks for the help.

He told me the best way to do it is to check the burn marks on all the spark plugs under load on the lake.

 

[Scott Danforth]

So the engine was a crate small block from summit racing that we "marined". We put all of the boat stuff from the old mercruiser 5.7 that the boat came with (1990 sea ray bowrider 190) and that motor had the thunderbolt IV ignition. My buddy did the work he's a mechanical engineer and builds race cars from the ground up. We had and old 350 on it for years but it was a junkyard pull and eventually lost compression. So 3 years ago I bought the boat from him and we put the crate motor in it. Ran great always made good power. We put the delco voyager est in once the module went bad on the thunderbolt IV. That was about a month ago since then had the boat out twice and just doesn't feel as responsive at the throttle.

I guess I should have stated what the motor actually was when I posted lol. He knows way more about it than me and he told me we need to find out what the curve on the TB IV was because that worked very well with the motor. If we get that curve and figure out the current curve in the delco module we can compare and maybe change out the module with one that has the best curve for the motor.

what cam is in the small block.

if it was a truck or marine cam you are fine.

if it was a cam for a hot-rod or a car, too much overlap and you probably suffering from reversion and the rusted out valves and the TB control module happening at the same time is a coincidence.

 

[SeaRaySalmon]

Scott, it was for a truck. Had it in the boat for over 3 years she runs very well. She still does run very well just throttle isn't as responsive and doesn't feel as powerful as she did before. If I sold the boat as it is the new owner probably wouldn't know any different. Gets up on plane and pulls me wakeboarding with passengers no problem. It just feels like it's not as good as it was and myself and my buddy believe it to be the timing and I trust his judgment because he knows motors inside and out. We just don't know what the timing curve on the current module is or the old one and I cant seem to find that info anywhere.

I went with th delco voyager est because from what I read it was a great replacement. I also don't know much about this stuff myself all I know is from what he's explained to me and my own internet research. I am far from an expert on any of this lol

 

[Scott06]

achris I am applying 12v using the shunt to set base timing. I have a little alligator clip and hook it to the battery. In the driveway when I rev it to check total timing it immediately jumps to 20 almost instantly and up 3k rpms seems like thats all it goes up to is 20 or maybe 22. But that is only in the driveway have not checked on the lake.

alldodge I'll have to check if my buddy still has the module and let you know thanks for the help.

He told me the best way to do it is to check the burn marks on all the spark plugs under load on the lake.

You need at least 26 degrees total advance. I’d tweak the initial timing until u get Total of 28 or so at 3 k and see How it performs

 

[SeaRaySalmon]

achris turns out I had both modules in there at some point. Started out with the 22A and when that died I put a 22 I had that we kept as a spare. Both seemed to work better than what I have now. If you could send me the curves for both I'd appreciate it.

I ordered a new module off of Amazon I will post the link. One review said it has about 21 degrees of advance built into the module so base timing set to 10 should give me 31 degrees at speed.

https://www.amazon.com/dp/B00BLTJR26/ref=cm_sw_r_cp_apa_i_kM6gFbJ2Y1Y82

It was only 40 bucks and I figure I can keep the current module moduhe boat in the glove box as a soare because my buddy says modules in general are super unreliable (hence why we had the spare v8-22 module as a back up on the boat)

I also ordered a full set of new spark plugs so we can try and fine tune it on the water. I will let you guys know how it goes.

 

[achris]

... because my buddy says modules in general are super unreliable ...[/QUOTE]

As long as you alternator isn't throwing ginormous voltage spikes, modules are actually very reliable.

Here's the curves...

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[SeaRaySalmon]

Thanks achris based on the curves you sent if the module I ordered has 21 degrees of advance built in I should be right on to match the 22A hopefully.