BIG 1996 Shamrock 220 WA Project

CrewTwo

Active Member
Sep 7, 2018
38
5
I have seen many threads on problems with TBI not working properly. I am slightly hesitant about posting this, but here was my solution.
5 years ago, I had the same problem. Replaced fuel pump. Cleaned everything. Injectors still would not work. I was told to change out the module in the distributor. Tried that, still nothing. Since the inside of the distributor was badly corroded, I replaced the whole distributor. Wires and cap were just replaced previous year. Turned the key, injectors fired, and she ran perfectly until I replaced the whole motor last spring. Not sure what was the culprit, but that worked for me.
 

deputyrpa

Well-Known Member
Supporting Captain
Aug 28, 2010
1,193
85
Fort Ann, NY
She runs!!!

Replaced the first fuel pump this morning, sure enough got great fuel pressure. Guess it was the fault of the second pump all along.

Turned the key and she started like a dream! You would never know it hadn't started in 15 years. Going to check the oil later and make sure there's no water in it, as long as that's fine I believe I've got a good running engine.

Honestly in complete shock.
Good news! Was the bad pump the low pressure pump or the eBay special?
 

jacksonsullivan

Active Member
Jul 29, 2008
41
2
Longboat Key Florida
Thank you all for the kind words. Today I started her up again. She was running much rougher than yesterday, but I'm still thrilled she runs at all.

Initially I was getting nothing out of either injector, but with some persuasion started to get a spray out of the starboard injector. The port injector never sprayed.

I suspect running it for the first time yesterday in ages led to it sucking up some gunk still built up in the lines. I plan to replace all the fuel lines before next season, and maybe add an additional in-line fuel filter. Anyone have any thoughts or suggestions?

just for info in case it ever becomes usable, I had an issue about a decade ago after having new fuel tanks installed and it ran really rough and rich and I found a pinch in the fuel return line. Other than that I’m actually shocked the TBI system has functioned without any problems… ever. The module looks like hell but from what I’ve heard and experienced, the Indmar setup seems pretty robust.
 

boataddict

Well-Known Member
May 19, 2020
170
33
Point Pleasant, NJ
I have seen many threads on problems with TBI not working properly. I am slightly hesitant about posting this, but here was my solution.
5 years ago, I had the same problem. Replaced fuel pump. Cleaned everything. Injectors still would not work. I was told to change out the module in the distributor. Tried that, still nothing. Since the inside of the distributor was badly corroded, I replaced the whole distributor. Wires and cap were just replaced previous year. Turned the key, injectors fired, and she ran perfectly until I replaced the whole motor last spring. Not sure what was the culprit, but that worked for me.
Interesting, I'll definitely keep that in mind if all else fails. Right now I think I'm dealing with fuel clogs for sure but we'll see.
 

boataddict

Well-Known Member
May 19, 2020
170
33
Point Pleasant, NJ
Good news! Was the bad pump the low pressure pump or the eBay special?
The bad pump was the low pressure pump, turns out that the old one was fine all along. The eBay special high pressure pump works great. The low pressure pump I had replaced, but I guess the low pressure pump I replaced it with didn't have enough power. Put the old one back on and combined with the new high pressure pump it ran like a champ that first day.
 

boataddict

Well-Known Member
May 19, 2020
170
33
Point Pleasant, NJ
My plan for this weekend is to disconnect the end of the low pressure fuel line where it connects to the high pressure pumpI. I'm going to attach an extended line at that point through some filters and recirculate the fuel back into the tank. Hopefully that in combination with the Star Tron fuel tank cleaner will help clean the fuel system out. I'll take apart the injectors and spray them out as well, then hopefully after flushing the system like that for a while I'll be good to go. I suspect the remnants of the old gas in each tank is the culprit for all of this.
 

deputyrpa

Well-Known Member
Supporting Captain
Aug 28, 2010
1,193
85
Fort Ann, NY
The bad pump was the low pressure pump, turns out that the old one was fine all along. The eBay special high pressure pump works great. The low pressure pump I had replaced, but I guess the low pressure pump I replaced it with didn't have enough power. Put the old one back on and combined with the new high pressure pump it ran like a champ that first day.
Awesome to hear, because I bought one as a backup. LOL!!
 

boataddict

Well-Known Member
May 19, 2020
170
33
Point Pleasant, NJ
So I took apart the TBI to get a look at the injectors. What a mess! Definitely got clogged up with what must have been the remnants of the old fuel and junk in the tanks. I cleaned them out again easily enough.
To tackle the source of the problem my plan currently is to add gas to the tank to dilute some of the junk (only had about 5 gallons in it). As well as add more of that star Tron fuel tank cleaner. After letting that sit, I'm flushing the system by pumping it through a small in-line filter back into the tank and just letting that run on a cycle. Hopefully I can clog up a few filters and get some cleaner looking fuel out of all this.
PXL_20211001_215440217.jpg
 

boataddict

Well-Known Member
May 19, 2020
170
33
Point Pleasant, NJ
I admire your relentlessness in working through issues. You will be rewarded with a boat that gives you a lot of great times and one you are very in tune with the nuances of. Thanks for the inspiration you are giving the rest of us.
I can't wait. I'm thrilled it runs, not rushing it from this point. Don't have time to use it this fall anyway, so I'm focusing on getting things dialed in and done right for next spring.
 


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