Carb to Fuel injection conversion?

[jimmer2880]

Originally Posted by east tx skier

I think there are two injectors on the Indmar TBI setup.

Correct, my TBI has 2 injectors.

If I remember correctly, I thought our stock MC TBI's were the same as an early 90's Camaro.

[[email protected]]

Hey, I have had a lot of experience in this - and there is hope for you! TBI Injection is fine for the reliability that you're after, and a complete kit with in-tank fuel pump, high pressure lines, filter, and the TBI will run you around $1500 and take a fairly skilled back yard mechanic 8-10 hours to install. Electrical work is also required.

Port Injection aftermarket kits for marine apps don't really exist - you'd have to retrofit from a totalled boat, including HEI ignition and the manifold. It would be a major hassle...

The good news is this: I've been through it twice on my last two PS190 boats. The simple fact is that marine carbs aren't built to last 15 years. That doesn't mean, however, that they aren't any good. If you want an easy, fast, painless solution, I'd go down to the local NAPA store in your town, and have them order you a brand new HOLLEY Marine carb for your boat (4000 series, probably). They retail at MC dealerships for $730, but go for $509 at NAPA!

Trust me on this one - I've done it twice, and my boats start on the frist turn of the crank, and run like a fuel injected boat. Most people can't believe how well my boats run...

Good luck!

TIM

[[email protected]]

Oh - One more thing - VERY IMPORTANT!!!!

NO Carb or FI designed for street cars is either SAFE or EFFECTIVE on a boat! Please don't try it.

TIM

[jake]

Originally Posted by [email protected]

Hey, I have had a lot of experience in this - and there is hope for you! TBI Injection is fine for the reliability that you're after, and a complete kit with in-tank fuel pump, high pressure lines, filter, and the TBI will run you around $1500 and take a fairly skilled back yard mechanic 8-10 hours to install. Electrical work is also required.

Port Injection aftermarket kits for marine apps don't really exist - you'd have to retrofit from a totalled boat, including HEI ignition and the manifold. It would be a major hassle...

The good news is this: I've been through it twice on my last two PS190 boats. The simple fact is that marine carbs aren't built to last 15 years. That doesn't mean, however, that they aren't any good. If you want an easy, fast, painless solution, I'd go down to the local NAPA store in your town, and have them order you a brand new HOLLEY Marine carb for your boat (4000 series, probably). They retail at MC dealerships for $730, but go for $509 at NAPA!

Trust me on this one - I've done it twice, and my boats start on the frist turn of the crank, and run like a fuel injected boat. Most people can't believe how well my boats run...

Good luck!

TIM

Tim: I love to hear from people with practical experience. What benefits do you see to a new carb over rebuilding the existing one. I have the 4010, but don't really have issues with the hot stalls, which is the primary reason to abandon the 4010 from what I've heard. I just can't get it to idle reliably, I have to run it quite rich to get easy starts and smooth idle.

[JimN]

The TBI system on the boats is really the same as what was used on cars and trucks. There's a septum in the intake manifold and one injector feeds each. It's not an Indmar system, Indmar takes an existing one and adapts it for marine use.

[JDK]

Originally Posted by JimN

Indmar takes an existing one and adapts it for marine use.

....except for the damn fuel pump (the engine mounted one with the internal by-pass). I've looked and looked and looked for a 'generic replacement'.
Any ideas as to what other applications this pump may have been used in???

[Credo]

The only question that I have with using a car multiport injection system ona boat would be the 02 sensor. I know that Ford ECU's take their main readings from the MAF and O2 sensor wouldn't a wet exhaust system corrupt the reading from the 02 sensor? And make the engine think its running rich?

[gr82bgreen]

Originally Posted by Credo

The only question that I have with using a car multiport injection system ona boat would be the 02 sensor. I know that Ford ECU's take their main readings from the MAF and O2 sensor wouldn't a wet exhaust system corrupt the reading from the 02 sensor? And make the engine think its running rich?

You could run it without the sensors. it would be in open loop and would set codes, but it would run fine. The maf was not used on the older speed density system, but that system is calibrated to the car or trucks camshaft. I think the boat cam would run ok though. I don't know how the prograqming would translate form a car or truck, to a boat though. Ive heard its a bad idea to install automotive efi on a boat. probably cheaper and less headaches to upgrade to a new boat with efi. You would need lots of new parts, intakes, new fuel pump and lines, ecu, a wiring kit to make it work. would have to find a dry sealed place for the comupter.

[JimN]

Originally Posted by [email protected]

Oh - One more thing - VERY IMPORTANT!!!!

NO Carb or FI designed for street cars is either SAFE or EFFECTIVE on a boat! Please don't try it.

TIM

The real difference between a stock GM EFI engine and these is the fact that, if the engine stops running with the key ON, these boat engines shut off because they're programmed to. Other than that, it's basically standard stuff. The LTR and some other intake manifolds are different but the rest isn't exactly what would be considered 'exotic'.

[JimN]

Originally Posted by gr82bgreen

You could run it without the sensors. it would be in open loop and would set codes, but it would run fine. The maf was not used on the older speed density system, but that system is calibrated to the car or trucks camshaft. I think the boat cam would run ok though. I don't know how the prograqming would translate form a car or truck, to a boat though. Ive heard its a bad idea to install automotive efi on a boat. probably cheaper and less headaches to upgrade to a new boat with efi. You would need lots of new parts, intakes, new fuel pump and lines, ecu, a wiring kit to make it work. would have to find a dry sealed place for the comupter.

If you disconnect the TPS, it will default to 12% throttle position at all times and that won't run "fine". If the MAP sensor is disconnected, the ECM will have no idea how much fuel to deliver, so that will default to a setting that won't allow good performance. If the ECT is disconnected, the ECM will think the engine is at about -40°F, or below, so it will run exceptionally rich. If the knock sensor is gone, it will want info, so it will prevent correct timing advance and throw a code, too. How does this qualify as "fine"?

A really easy way to upgrade to EFI is to buy a GM Performance Parts crate motor, like the 350 RamJet. 350HP/390Ft-lb of torque, it uses the same ECM and any GM dealer can service it when the warranty is still in force. The thing about MC- they calibrate teh engine to the boat, not a generic weight load.