Help with mariner 2.4l 175 efi

[Partonjoshua]

Hey guys been lurking a while on the forums trying to figure this thing out. Here's my problem I bought a 94 astro 18fsx with a 175 mariner 2.4 efi serial number oc155438. The thing starts and runs great on muffs but will not plane out on the water.

Here is what I have done to it so far
1. New stator
2. New voltage regulator.
3. New switchboxes
4. New trigger
5. New fuel pump
6. Cleaned fuel system and replaced most of the lines
7. Compression was good.
8. Checked timing

My latest problem is now in addition to not planing out and running like crap, the fuel pump will now run non stop with the ignition on or off, the only way to get it to stop running is to disconnect the battery or unplug the ecu. I'm thinking bad ecu but wanted y'alls opinion before sending it to Simon's motor sports to have it tested and rebuilt. Thanks and sorry about the long post, but I'm about to burn this boat if I don't get it going.

 

[Dukedog]

first off check tha serial number again. 0C155438 comes up as 9.9 hp.on MercNet?.. number on ecu?.. think ecu is gonna be tha problem....but justa guess at this point.

 

[Partonjoshua]

Your right number on engine is 0c155938, I will check the number on the ecu when I get off work.

 

[Dukedog]

shows 175 mariner ski...... i put it in wrong tha first time... i'm old!

 

[Partonjoshua]

I don't know why it's doing that on marine engine.com it pulls up as a mariner 175 ski

 

[Partonjoshua]

On my first post I thought the 9 was a 4. When I plug in oc155438 it comes up as a 9.9, but oc155938 comes up as the 175.

 

[Dukedog]

things happen when ya jus "copy n paste".. on same track now.. still need ecu number... tha 2.4 ecu's are analog and are what they are... tryin' ta "fix" one is a real trick that seldom works.... even by tha best..

 

[Dukedog]

justa note.. if tha pump is runnin' with tha key off ya have a wirin' problem somewhere... tha pos at tha pump is supplied thru tha ecu BUT should not be hot until tha key is turned on...that red should only come hot when tha ecu hot circuit comes on with a switched purple... that purple is tha only 12v source for tha ecu AND tha pump.... have ya got a wirin' dia. for it?

 

[Partonjoshua]

Didn't wanna hear that, I guess I will send it in to at least get it diagnosed before dropping big bucks on a new one. I won't be able to get the number on the ecu tonight, but can get it tomorrow. Are all 2.4l ecu's interchangeable?

 

[Partonjoshua]

Don't have a diagram but I can look around to find one. If it is a wiring problem should it be between the ignition switch and the ecu? Or between the ecu and fuel pump?

 

[Dukedog]

something is makin' tha switched purple (ahead of ecu) hot all tha time if ya have to disconnect tha batt ta shut tha pump off.. it (purple) should only come hot when tha switch is in tha "on" position...

they only built tha efi in a 220 ('87 and '88).. then tha 175 SKI and 200 ('89 and '90) in tha 2.4.. '91's up were 2.5's.. you need tha '89/'90 175 or 200... tha '87/'88 were junk.. had a lean spot in 'em at most folks "crusin'" speed.. new is gonna be a chore ta find.. close ta impossible... used will be almost as hard but you can make sure tha seller will refund if its DOA or no deal!

 

[Partonjoshua]

OK I will take a look tomorrow and try to figure out what's causing the purple wire to stay hot

 

[Partonjoshua]

How about a 1990 200 Bridgeport ecu

 

[Dukedog]

there is no 200 BP.. even carb BP is rated 220...hi perf 200 (mod- vp) is gonna be an oval port.. block half same as yours only "naked" (no paint).. BP efi is 240... absolute only way ta know if an ecu ( any of 'em) will run on it or not is put it on and see....no mater what it comes from... don't think merc has ever built two ecu's tha same... some are close but no cigar that i know of.....

there is one ecu in particular thats tha best for a 2.4 but its no very common.. it came on a 1987 BP motor merc called a Bass (laser) injected BP....was bought off tha merc truck at an apba race... most, not even tha well versed hi perf guys, know of its existance... I'll see if i still have tha ecu number for it... might get lucky..

 

[Partonjoshua]

Yeah I found it on eBay and he said it was a 1990 200 bridgeport thought that sounded a little off, his ecu number is 14632a2 mine is 14632a12. Guess I'll just bite the bullet and order it and see what happens after I figure out my wiring problem.

 

[Dukedog]

early BP (late 80's) had 11350 a7 or 13's.. later came tha 11350 a40's... think tha a7 is what was on tha motor i talked about in above post...

wouldn't order or buy anything till ya figure out why tha pump runs with tha key off...

 

[Partonjoshua]

Yeah I'm gonna figure that out before I do anything else. Thanks I will keep you updated

 

[Dukedog]

purple at motor hot with key off i'd be lookin' at tha key switch pretty hard first....

 

[Partonjoshua]

If purple coming directly out of the switch is hot with the ignition off this indicates a faulty switch correct?

 

[Dukedog]

probably so but there is an "outside" chance of it being in tha harness somewhere also.. jus not much..