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'95 350 Mag TBI: How to clean TBI?

P

pwskicat

Regular Contributor
Ser. #0F562552. I am not a mechanic and this is the first TBI engine I've seen, so please excuse my ignorance. This is a 2-barrel TBI engine with a MEFI-1 ECU. Removed the the flame arrestor to clean it and the injectors sitting atop the TB and the TB itself look kinda grungy. There's no problem with performance, and I'm big on "If it ain't broke." So should I clean things up or not? If so, how do I apply the Carb/TB cleaner? (Using Valvoline or Gumout.) Do I shoot it thru the flame arrestor (Now Clean)? Spray it just on the TB, not hitting the injectors? Spray on injectors and TB?

Many thanks or your help, PW
 
pwskicat said:
Ser. #0F562552. I am not a mechanic and this is the first TBI engine I've seen, so please excuse my ignorance. This is a 2-barrel TBI engine with a MEFI-1 ECU. Removed the the flame arrestor to clean it and the injectors sitting atop the TB and the TB itself look kinda grungy. There's no problem with performance, and I'm big on "If it ain't broke." So should I clean things up or not? If so, how do I apply the Carb/TB cleaner? (Using Valvoline or Gumout.) Do I shoot it thru the flame arrestor (Now Clean)? Spray it just on the TB, not hitting the injectors? Spray on injectors and TB?

Many thanks or your help, PW
Click to expand...


you can spray them both or spray the carb cleaner on a rag and wipe down, don’t overthink it too much. Might be worth sending the injectors for cleaning and flow testing next winter to stay ahead of any potential internal clogging .

I assume since you say it’s running well that the fuel starvation issues you were fighting last year got solved? Or is this a different boat ?
 
carburetor cleaner or throttle body cleaner

Some say there's different and not to mix...or is it really just marketing?
 
I'd add a couple bottles of STP injector cleaner to the tank. It's done wonders for several of my vehicles with messed up injectors.

Jeff
 
Dieter said:
you can spray them both or spray the carb cleaner on a rag and wipe down, don’t overthink it too much. Might be worth sending the injectors for cleaning and flow testing next winter to stay ahead of any potential internal clogging .

I assume since you say it’s running well that the fuel starvation issues you were fighting last year got solved? Or is this a different boat ?
Click to expand...

Hi Dieter! Good memory. Same engine, same problem. It'll run all day at 3400 rpm (31 mph), but a little faster and it surges, try WOT and it spits and quits. Nobody that goes out with me skis over 30 mph, and I'm now wake boarding at 18 mph. I found a company here in Michigan that will sell me a new MARINE TBI kit designed for the GM 350 V8 for $1,100:

TBI - 1.750 TBI fuel injectionWiring Harness
High-output Marine Electric Fuel pump
Mechanical Fuel Pump Block Off Plate
Fuel tubes
Installation instructions
Heated O2 Sensor
Oxygen Sensor Block for the Exhaust W/gaskets
Map Sensor
IAC Sensor (Idle air control motor) New on TBI
TPS Sensor
Coolant Temperature Sensor
Necessary hardware and gaskets to mount system to intake manifold
(Please specify what brand Manifold you have)
Fuel filter
Fuse link
Air cleaner stud
Distributor cap
ECM with custom calibrated EPROM chip

His Ebay store (performancefuelinjectionsystems) has a 98.5% rating and it's sold 125 of these kits. COVID hit me hard in the wallet. Had to take a 30% pay cut, so I gotta find some extra cash if I want to get the kit. (Definitely a first-world problem.) Thanks for the advice. Hope you and yours are all safe and well. PW

 
If you are happy with how the engine is running, stay true to your philosophy.

If the injectors are malfunctioning, I've found it is best to send them to a shop that cleans them ultrasonically and then measures their flow rate to ensure uniformity.
 
pwskicat said:
Hi Dieter! Good memory. Same engine, same problem. It'll run all day at 3400 rpm (31 mph), but a little faster and it surges, try WOT and it spits and quits. Nobody that goes out with me skis over 30 mph, and I'm now wake boarding at 18 mph. I found a company here in Michigan that will sell me a new MARINE TBI kit designed for the GM 350 V8 for $1,100:

TBI - 1.750 TBI fuel injectionWiring Harness
High-output Marine Electric Fuel pump
Mechanical Fuel Pump Block Off Plate
Fuel tubes
Installation instructions
Heated O2 Sensor
Oxygen Sensor Block for the Exhaust W/gaskets
Map Sensor
IAC Sensor (Idle air control motor) New on TBI
TPS Sensor
Coolant Temperature Sensor
Necessary hardware and gaskets to mount system to intake manifold
(Please specify what brand Manifold you have)
Fuel filter
Fuse link
Air cleaner stud
Distributor cap
ECM with custom calibrated EPROM chip

His Ebay store (performancefuelinjectionsystems) has a 98.5% rating and it's sold 125 of these kits. COVID hit me hard in the wallet. Had to take a 30% pay cut, so I gotta find some extra cash if I want to get the kit. (Definitely a first-world problem.) Thanks for the advice. Hope you and yours are all safe and well. PW
Click to expand...
I was hoping to hear that it was fixed, hopefully the aftermarket unit you mention will fix it. I assumed it had to be from the removal of the VST, maybe worth cleaning the injectors ?

at least you can use it for skiing and boarding. I ended up putting a tower on my sea ray 200 this spring amazing how much easier it is to board.
 
Glad u got a tower on yr boat. Definitely makes getting up easier. My boat has a tower too. What speed do you board at? my boat throws the best wake at 18mph. I put in a GPS speedo and it makes running everybody's favorite speed a piece of cake. I'm looking into having the injectors cleaned. Also doing a completed tune up with cap, rotors, wires and plugs. Also replacing the mechanical lift pump on the engine block.
 
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