Mercruiser 7.4 LX MPI Won't Start - No Sparky

[dubs283]

I suppose I can run the Diacom Software and record the data while I take the boat out for a run and compare data from each engine

if it were my setup i'd check the full advance under load with a timing light, 454 can handle up to 36 degrees advance no problem

iirc you have one original distributor still good? why not use that as a baseline (set to idle timing with base timing mode), check idle/full advance running normal. drop new distributors in and set them the same way

 

[alldodge]

Manual list 27* advance curve and that the ECM controls

 

[tpenfield]

Manual list 27* advance curve and that the ECM controls

The manual that covers my engine is #16 . . . but it does not cover the HEI/EST distributor much, if at all. Probably because it is the first year of MEFI :noidea:

Which manual are you referencing? Manual #23 seems to cover the ignition system that I have, but is for the newer engines . . .

Here is the advance curve from Manual #16 . . .

 

[alldodge]

Using 23 because it does discuss it, and as you say 16 doesn't. Before my repower I to had a MEFI-1 and used 16. Manual 23 covers MEFI 1 and 3. Total advance for EST would be up to 35*.

 

[tpenfield]

Just doing some more research on the dizzy part numbers . . . which in fact is making me dizzy

Also, my thanks to Scott for chasing the numbers behind the scenes.

There are over a dozen GM part numbers that map back to the same distributor.

I have found 1 GM number that is marked "J1171" . . . a GM #1104065. The number on the label of the dizzy's that I got are 1104096, which is the ACDelco/GM number format, but I cannot find any info on the number. The boxes are marked with the Delphi label and number of CZ20001 . . . made in Mexico.

Looks like you can buy this same distributor assembly/part from various sources ranging from about $50 all the way to $700+ and it is the same part. Such craziness . . .

Since I plan on selling the boat in a year or 2, I'd like everything to be proper and viable for an inspection/survey.

 

[alldodge]

Would be easier I guess to pay the big bucks for the label

Side note: a guy on the Formula forum could use your 330 experience

 

[tpenfield]

Side note: a guy on the Formula forum could use your 330 experience

I'll check it out

 

[Lou C]

do tell Ted what's coming next....twin outboards....or inboards....

 

[tpenfield]

do tell Ted what's coming next....twin outboards....or inboards....

Thinking about 35-38 footers . . . twin or triple OB's. Got to keep this boat running for now

 

[alldodge]

380 SSC is only 840K :facepalm:

 

[Lou C]

Thinking about 35-38 footers . . . twin or triple OB's. Got to keep this boat running for now

wow that's really big...can you take the second home mortgage deduction on one of those lol!
funny thing I never had a desire to go bigger, in fact if I stay in boating I will stick with same size, just simpler maintenance of an OB more fishing friendly boat. KW 203 Dual Console with a 150 4 stroke. So I can still store it at home.

 

[tpenfield]

wow that's really big...can you take the second home mortgage deduction on one of those lol!

My 33 footer started out big, but now seems small I'd prefer 35 foot and twins, but I like the layout of some of the 38 footers better. . . those put you into triple OB's. . I have to save up some money first . . . so we'll see how that goes.

Here is a link to my current thinking on the next boat . . . https://forums.iboats.com/forum/gen...-engine-topics/10929030-time-for-a-‘new’-boat

 

[tpenfield]

Part ID Update . . .

I have not surfaced too much more about these distributor parts . . . I sent an inquiry into PSI a few days ago, and just sent an inquiry into Delphi Aftermarket today. So, I'll see if anything comes of it.

 

[tpenfield]

Update:

Here are a few updates to the Mercruiser ignition distributor 'saga'. . .

1) No word back from my inquiries to PSI or Delphi
2) Scott relayed some info from his contact @ PSI regarding the distributors . . . it looks like the same distributor is sold through a variety of channels, yet is single-sourced through China . Pricing on the exact same part varies widely.
3) I have yet to find any reference to the '1104096' part number which is stamped on the base of the dizzy and also labeled on the cap.
4) I put the other new dizzy in the port engine, and set the timing. Since I was having trouble with my laptop/software, I checked the timing w/o base timing mode before I changed the dizzy, and then made the new dizzy the same as the old.
5) I think it may have been my laptop that was a problem with the Diacom software (2-in-1 tablet/laptop), so I have another (older) laptop to try.
6) It seems to me that this style dizzy would be marine approved based on its design:
- Screens in the base
- Screwed down cap
- Electronically controlled advance - no vacuum advance
- No other holes/openings in the dizzy or cap.
- No physical differences between automotive and marine branded parts
7) Through my exhaustive searching (via Internet) I have seen many 'marine' distributors of this type without 'J1171' stamped on the base or otherwise labeled.

 

[alldodge]

Good info