New to me 2.4L Bridgeport EFI no start / fuel system questions

**pcrussell50** · 09-12-2023, 10:21 AM

Do these run at 40’ish psi like the early 1990’s Bosch automotive systems?

-Peter

**mxr181** · 09-12-2023, 10:58 AM

39 psi from what I’ve seen. The regulator and pump I have are both Bosch and searching those part numbers look like they were used by all the German car manufacturers back in the day

**pcrussell50** · 09-12-2023, 01:21 PM

Originally Posted by mxr181

39 psi from what I’ve seen. The regulator and pump I have are both Bosch and searching those part numbers look like they were used by all the German car manufacturers back in the day

Ford used that Bosch system too in the “Fiveoh” Mustangs. 39psi, vacuum indexed regulator, return-style fuel loop, same injector form factor, etc… They eventually moved to direct measurement of air flow using a mass-airflow sensor instead of inferring it from manifold pressure and throttle position. Pretty slick if Merc eventually followed suit, but I don’t know my Merc V6 lore well enough yet.

-Peter

**tlwjkw** · 09-12-2023, 02:12 PM

if you have a yellow/red in tha ecu harness goin' to the starter sol. then ya got a chance with cold start deal.. there should be a yellow/black on tha male side of tha boat harness at tha plug.. may be buried under tha tape but its there.. dig it out and usin' male and female bullet connectors join tha two together (tha yellow/red from ecu harness and yellow/black) then ya have a "push ta choke" with tha key.. same as with carbs.. you are in control pf tha "choke" part instead of tha start part of tha solenoid ..............

**25two.stroke** · 09-12-2023, 05:33 PM

At idle with vacuum they may run at 37 psi or so. WOT with no vacuum it shouuld be 39 to 40.
Flow test your injectors before you put the boat in the water.
Just do it.
Clean motor, it would be a shame to blow a hole in the side of it cause one injector is dribbling enough to make it idle good but cant flow at high rpm.

Did you buy the boat from Cowboy? He had one that looked just like that and same cowl. He had a 260 on it and I'm thinking he kept the 260 powerhead and sold you the boat and just dropped the 2.4 BP powerhead on?

**mxr181** · 09-12-2023, 09:13 PM

Yes I bought it from cowboy last weekend. Nice guy. I think he actually had his modded 2.5 200 efi on it but he definitely does have a 260 and maybe he had it on the boat previously? I think the mid section from this Bridgeport is on his 260 and he gave me the sportmaster off of it so def a mix of parts.

got the fuel pump routed correctly and she’s a runner! Flow testing the injectors is probably a very good idea, are you saying pull the rail off and pressure with the fuel pump or are you saying send them out for full calibration? Was really hoping to splash it this weekend BUT I totally hear you on doing it right to be safe

**25two.stroke** · 09-13-2023, 11:45 AM

Send them out. You can't tell from just watching them squirt...plus that makes a mess.
Well, you can tell somewhat, but not really what they are doing at high speed when it matters.

**mxr181** · 09-13-2023, 10:23 PM

Injectors going out tomorrow. Is this a std fishing mid? Seller said the Bridgeport powerhead was dropped on a 2.4 200 but it has a small “bullet” than the 200 2.4 I had. I’m assuming 150/175 black max mid. Reading in another thread there are different adaptors and cooling setups, also diff tuners which the Bridgeport tuner I was looking at sold. Trying to figure out exactly what I have and if anything needs to be changed to run it

**tlwjkw** · 09-13-2023, 10:48 PM

plain jane "bass production" mid... can't see tha tiller arm for age estimate?.. has tha production two piece adapter.. with that type adapter you will need to add a poppet assy. to tha block.. T-stats or restrictor washers with 3/8" holes required... discharge bib on tha poppet cover plate does not need to be there (no external water discharge from poppet with that type coolin')...

"but it has a small “bullet” than the 200 2.4 I had"...... ???

what bullet??? tha only thing i've ever heard called a "bullet" on any merc is tha hub of tha gear case and that was very rare... usually referred to as tha hub/nose cone..

**donmac** · 09-14-2023, 05:06 AM

Originally Posted by 25two.stroke

Send them out. You can't tell from just watching them squirt...plus that makes a mess.
Well, you can tell somewhat, but not really what they are doing at high speed when it matters.

that's how the merc diagnostic tool worked,you could fire selected injectors and change pulse, while watching discharge pattern! it would also allow you to set ecm for altitude if you were inclined to drill the case and dig out the potting! 2.02 for sea level i think,been 35yrs. though don't take my word for it!

**62 bugzilla** · 09-14-2023, 10:23 AM

Originally Posted by tlwjkw

plain jane "bass production" mid... can't see tha tiller arm for age estimate?.. has tha production two piece adapter.. with that type adapter you will need to add a poppet assy. to tha block.. T-stats or restrictor washers with 3/8" holes required... discharge bib on tha poppet cover plate does not need to be there (no external water discharge from poppet with that type coolin')...

"but it has a small “bullet” than the 200 2.4 I had"...... ???

what bullet??? tha only thing i've ever heard called a "bullet" on any merc is tha hub of tha gear case and that was very rare... usually referred to as tha hub/nose cone..

I've heard mixed comments if they need a poppet or don't with the 2 piece mid? If adding one which poppet assembly and plate since it's different than most motors in that area and do you have to modify the poppet area of the block to accept it? Don't want to side track the thread I have another one going with similar issue on cooling.

**mxr181** · 09-14-2023, 11:08 AM

All good! Pretty sure I got my fuel issue figured out, now moving on to the cooling. I would also appreciate the poppet details or what model to order them for. Mine def has flow through the motor though so curious to pull the poppet cover and see what I currently have. I need to find a good diagram and learn the whole system so I understand it better.

**pcrussell50** · 09-14-2023, 12:09 PM

As an outsider looking in, both of these currently hot Bridgeport threads remind me of the adventures of trying to live with a racing/competition motor, for ordinary recreational use. It will be interesting once you two have got your motors sorted out, how you like them in day-to-day boating use.

-Peter

**25two.stroke** · 09-14-2023, 12:36 PM

Originally Posted by 62 bugzilla

I've heard mixed comments if they need a poppet or don't with the 2 piece mid? If adding one which poppet assembly and plate since it's different than most motors in that area and do you have to modify the poppet area of the block to accept it? Don't want to side track the thread I have another one going with similar issue on cooling.

You do need a poppet with a 2pc adapter plate
If you don't have one then all your water will dump out before it fills the block up at low rpms.

**OnPad** · 09-14-2023, 01:11 PM

Just a few things I notice when looking at pics in post 38. The clamp looks to be late 90's. The two piece adapter plates look like they came off something post clamshell cowling. The two bolt poppet cover has a dump hose running to the adapter plate (never seen that before?). Must not be a poppet in it?
The poppet covers I've messed with take either the old style diaphragm 64877 with a thin rubber edge, or the newer metal reinforced edge version 14479. The later has a deeper cut in the housing, or thicker gaskets?