5.7L bravo 1 Water in cylinders 1 and 3 after overheat need advice

Rick Stephens

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Electric fuel pumps with no shaft hole started showing up in mid 90's. In 96 all the blocks were without.

My experience is the better breathing of the vortec will likely require larger jetting.
 

bruceb58

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My 96 has a mechanical fuel pump that feeds the VST.
You do not have a Vortec engine.

Count your intake manifold bolts...you have 12.

I think it was 1998 when Mercruiser started using Vortec engines, possibly 1997.
 
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mr300z87

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According to the parts site I like to use Merc started using electric pump in 1998 starting with serial 0L010037 which probably coincides with when GM ran out of the blocks with mechanical fuel pump machining. To keep things simple I am looking for a 88-95 engine which should allow me to reuse all my Merc hardware. My little 20 footer has plenty of power with a tired/week 5.7 engine so with a healthy 260 hp should be a lot of fun. Don't get me wrong an extra 20 HP from the Vortec head would be nice but not worth the added expense of the intake and fuel system. My plan is to get this boat in operating condition for the least amount possible then it will most likely go up for sale. I have a line on 1995 5.7L from a med duty van (camper) engine with 56K on it, supposedly it runs great the guy is 2 hours away so he is sending me a video of it running to start. Anybody know how hard it would to get to the plugs for a compression test while still in the van? Still may try and rebuild mine if its not to corroded. Sea Ray 7.4 engine run tomorrow, fingers crossed.
 

thumpar

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On a van you normal take the doghouse that is between the front seats off to access the engine.
 

mr300z87

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That's interesting Rick? He told me it had a mechanical pump. Will check for sure.
 

NHGuy

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But Rick has a V6 maybe they made the move off the mechanical pump at a different time on that engine.
 

thumpar

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Just make sure if it has a plate where the fuel pump goes to check under it. Just because they have the plate doesn't mean it has a hole behind it.
 

mr300z87

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Did not realize he was talking about a 4.3. That makes sense now. Still going to double check. Hope to go check it out this weekend.
 

Rick Stephens

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But Rick has a V6 maybe they made the move off the mechanical pump at a different time on that engine.

Yah. Sorry if I diverted. Reality rules, only reason I can think of to have a block off plate is there's a hole behind it.
 

thumpar

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Yah. Sorry if I diverted. Reality rules, only reason I can think of to have a block off plate is there's a hole behind it.
There was a thread about a month ago where the person bought an engine and removed the blockoff plate to find it was solid. My only guess is that they were crossover years so some had a hole and some didn't and the workers just put a plate on all of them.
 

Rick Stephens

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There was a thread about a month ago where the person bought an engine and removed the blockoff plate to find it was solid. My only guess is that they were crossover years so some had a hole and some didn't and the workers just put a plate on all of them.

I think I remember that. Weird stuff. And point taken.
 

mr300z87

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This is GM at it finest?? I am not much of a GM fan. I have owed a 68 Plymouth Satellite Road Runner Clone for 20 years and love working on Mopar BB engines. I grew up in the 80s when everybody and the brother had Iroc Z28s and Trans Am. The engine in these cars we junk especially the 305/5.0L. I personally knew a couple guys that blew them up at 60K. LOL I know the 350 was better than the 305. I must say that up until a month ago the 5.7L in my Invader has always run flawlessly.
The guy with the engine I am interested in said it had a mechanical pump but also said it was a TB FI. Did GM use mechanical pump on early FI engines? I would hate to drive 2 hours for this engine only to find out that it does not have mechanical pump set up. I really want to stick with the Merc stuff I have and not create a mess.
 

bruceb58

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This is GM at it finest?? I am not much of a GM fan. I have owed a 68 Plymouth Satellite Road Runner Clone for 20 years and love working on Mopar BB engines. I grew up in the 80s when everybody and the brother had Iroc Z28s and Trans Am. The engine in these cars we junk especially the 305/5.0L. I personally knew a couple guys that blew them up at 60K. LOL I know the 350 was better than the 305. I must say that up until a month ago the 5.7L in my Invader has always run flawlessly.
The guy with the engine I am interested in said it had a mechanical pump but also said it was a TB FI. Did GM use mechanical pump on early FI engines? I would hate to drive 2 hours for this engine only to find out that it does not have mechanical pump set up. I really want to stick with the Merc stuff I have and not create a mess.
It likely has the spot for a mechanical pump blocked off with a plate but the engine uses an in tank electric fuel pump. It's not that big of a deal to use an electric fuel pump as long as you wire it up so that it uses oil pressure or the start solenoid to run it.

Funny what you say about the 5.0L vs the 5.7 since they are the identical block!

Like most engine issues, they are usually owner induced kinda like the problem you are having with this engine.
 

Rick Stephens

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I went through the same progression. Wasn't really comfortable with an electric fuel pump going into my boat. Seemed like one more failure point. However, when I look at my family's vehicles around my yard, realized the only one with a mechanical fuel pump was my 'mid-life crisis' Jeep that had a mechanical fuel pump in it. I went with an OEM setup, using the Airtex E11003 fuel pump and all the Mercruiser mounting and plumbing hardware to make a clean, and safe, install. Works flawlessly, so I get more comfortable with it every day.

Point is, don't let electric fuel pump run you off. It is the rarity in today's vehicles to have a mechanical pump.

fuelpump.jpg
 

bruceb58

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Rick Stephens you realize it is illegal and very unsafe to have a priming bulb on anything but an outboard motor and not in a bilge right?
 

Rick Stephens

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It can't be in the bilge.

My apologies for hijacking a thread.... but Define 'bilge'.

It would not be hard to move up a couple feet under the rear deck, but that is still one 'space' with the bilge. No different than sitting on the floor but inside the doghouse, where it is. Could also replace with an electric fuel pump and a momentary switch, I guess. Never even thought about it.
 
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