ECM and Distributor

[Tail_Gunner]

Re: ECM and Distributor

View attachment 113898 That would be a simple solution if your unit has it....Here are the codes


GM Part No. MEFI Type
16159919 MEFI-1
16189069 MEFI-1
16220371 MEFI-1
16234539 MEFI-1*
16210729 MEFI-2
16237009 MEFI-3
16237019 CEFI-3
16236999 MEFI-3*
12489488 MEFI-3
12489493 MEFI-3
12569494 MEFI-4
12575479 MEFI-4a
88962717 MEFI-4a
88962718 MEFI-4a
12584052 MEFI-4b
12597744 MEFI-5
12607802 MEFI-5a

MEFI 1 and MEFI 2 packaging

And if its not a mefi there are still codes some place

 

[John_S]

Re: ECM and Distributor

MM say they only use factory cams so should be able to get specs elsewhere since they said they do not have them.

Did they give you a GM factory cam part number?

 

[HFXJACK]

Re: ECM and Distributor

Finially got the answers
Item 2 34 psi
Item 3 dropped 3 psi
item 4 dropped 6 psi

Question Corect me if I am wrong. The fuel flows from outlet of fluid cooler to inlet of Pressure regulator the outlet of regulator to the fuel rail and returns to fluid cooler. The fuel from the gas tank flows from primary pump to fluid cooler. So Fuel cooler has two inlets, one from rail, one from fuel pump and one outlet to the pressure regulator.

If this is correct then what stops the primary pressure from main fuel pump backfeeding on to the fuel rail?

 

[Tail_Gunner]

Re: ECM and Distributor

The chances of you having a fuel delivery problem is extremely remote.....Aka midrange preformance is no problem. Yet at the extemes....idle and top end speaks volumes...the afr is not working.

 

[HFXJACK]

Re: ECM and Distributor

The chances of you having a fuel delivery problem is extremely remote.....Aka midrange preformance is no problem. Yet at the extemes....idle and top end speaks volumes...the afr is not working.

Sorry what is the "AFR"Bottom end does not work stalls if I do not bring throttle back very very slow it's been a long day

 

[HFXJACK]

Re: ECM and Distributor

Thats all well and good, but doesn't really tell you anything other than you probably had very little fuel pressure.

Try this from the manual.
What is the answer to the following questions highlighted in yellow from the picture below?

2. _34_______

3. _3_______

4. _6_______

Question Corect me if I am wrong. The fuel flows from outlet of fluid cooler to inlet of Pressure regulator the outlet of regulator to the fuel rail and returns to fluid cooler. The fuel from the gas tank flows from primary pump to fluid cooler. So Fuel cooler has two inlets, one from rail, one from fuel pump and one outlet to the pressure regulator.

If this is correct then what stops the primary pressure from main fuel pump backfeeding on to the fuel rail?

 

[HFXJACK]

Re: ECM and Distributor

Can we start over...so far i picked this up.....

Running Rich Update
From a previous thread I have a 1999 7.4 MPI. I replaced the engine with Reman long block from Michigan Motorz. Since the install the engine is running very rich at idle. At all other speeds it appears to be running normally. We have tested and tried everything possible. Leaving only replacing the ECM as the option. We placed an order for a new ECM from Mercury July 4th and are still waiting for a ship date. We keep getting a revised ship date at the expiration of current ship date. It's like pulling teeth talking to Mercury which is most unfortunate and certainly will influence any future engine selections. There customer service sucks. What little info I did get is that these ECM'S are not new units but core returns. I sent my ECM back to get flashed but it will not accept the flash. Loads to 65% and crashes whick kind of supports that I have a bad ECM.

My Question apparently my ECM package is obsolete and no longer supported, Is there a upgrade path option for me. Can I replace my existing ECM package to one of current generation?

1. there is a code on the ecu could you plz post that code.
2. Yes a ecm can compensate for small cam changes
3. Id call MM and tell them that you need to reprogram your ecu and the cam specs are vital.....aka known cam specs can cost you as little as 200 to tune.... unknown could cost you thousands aka a custom tune....
4. Are you using the orignal ecu or did you get a new one or used one???

Dong a proper tune on a boat engine is very simple if you source it right...The problem is there is very little support for that. However it can be done and with very good results. If you know the valve train type...cam specs and the ecu type maybe a few hundred...Try to post as much as possible

My code is 16210729
Cam Part # is 431-850453-T

Thanks
John

 

[HFXJACK]

Re: ECM and Distributor

Finially got the answers
Item 2 34 psi
Item 3 dropped 3 psi
item 4 dropped 6 psi

Question Corect me if I am wrong. The fuel flows from outlet of fluid cooler to inlet of Pressure regulator the outlet of regulator to the fuel rail and returns to fluid cooler. The fuel from the gas tank flows from primary pump to fluid cooler. So Fuel cooler has two inlets, one from rail, one from fuel pump and one outlet to the pressure regulator.

If this is correct then what stops the primary pressure from main fuel pump backfeeding on to the fuel rail?

So I answer the question with no reply was it something I said?

 

[joewithaboat]

Re: ECM and Distributor

I know nothing at all about Michigan Motorz, they could be the best in the reman world. However... I worked in a fully equipped performance oriented machine shop for two years. We often tore down and went through "remanufactured engines" because the owners were less than happy with their performance. I could write a book on all of the weird things we found, but in general most clearance specs are on the loose side. Bearings, pistons, rings, valves. They use cheaper parts everywhere. Even the best part have a plus or minus spec for quality control. Cheap parts have MUCH looser acceptable standard.
As far as machine work, we found... decks, mains out of parellel, deck different height side to side, one head surfaced much more than the other, even different over bore from one cylinder to the next. :facepalm: Heads that have only some guides or seats replaced. Guides often off center or angle off. Some new valves some used. Improper installed height of valves. Very poor vavle jobs. The list goes on......

Problems that might fit your o/p... We often saw cams that had be reground out of acceptable spec after having been repaired. Timing chains that were way off.

Overall reman is half the price of new for a reason. It?s not really fair to expect them to perform as a new one would. I?m not really saying that reman is a terrible thing. It?s a great way to save some money, but it is what it is. Some people that have had good luck with reman can now throw stones at me.
I hope you find your problem soon, good luck happy boating

 

[HFXJACK]

Re: ECM and Distributor

I know nothing at all about Michigan Motorz, they could be the best in the reman world. However... I worked in a fully equipped performance oriented machine shop for two years. We often tore down and went through "remanufactured engines" because the owners were less than happy with their performance. I could write a book on all of the weird things we found, but in general most clearance specs are on the loose side. Bearings, pistons, rings, valves. They use cheaper parts everywhere. Even the best part have a plus or minus spec for quality control. Cheap parts have MUCH looser acceptable standard.
As far as machine work, we found... decks, mains out of parellel, deck different height side to side, one head surfaced much more than the other, even different over bore from one cylinder to the next. :facepalm: Heads that have only some guides or seats replaced. Guides often off center or angle off. Some new valves some used. Improper installed height of valves. Very poor vavle jobs. The list goes on......

Problems that might fit your o/p... We often saw cams that had be reground out of acceptable spec after having been repaired. Timing chains that were way off.

Overall reman is half the price of new for a reason. It?s not really fair to expect them to perform as a new one would. I?m not really saying that reman is a terrible thing. It?s a great way to save some money, but it is what it is. Some people that have had good luck with reman can now throw stones at me.
I hope you find your problem soon, good luck happy boating

Thanks for the feedback. New was at the time not in the budget thought reman was my next best option. She went back on the hard today for round three or is it four?
I'll post the results