ECM and Distributor

[HFXJACK]

I have been having an issue with running rich at idle and low engine vacuum on a remanufactured engine. Extensive testing done by several mechanics Mercury certified leading consensus is that the cam may be out a tooth. I am have difficulty with this as the engine runs fine from 1K to 4.3K WOT. Very smooth in operation. One opinion is that the ECM can compensate for the Cam. So my question and one I am more comfortable with. Is is possible that the distributor is off by a tooth and the ECM is compensating for that?

Thanks

 

[Don S]

Re: ECM and Distributor

Do we win anything if we guess what engine, year, distributor, type of ECM and fuel injection you have?

 

[mpdive]

Re: ECM and Distributor

No before you even tell me any info. There is only so much advance curve built into the programing of the ECM. What happens when you need curve and it's already used up trying to compensate for an offset cam. Where's the rest of the curve gonna come from?

 

[HFXJACK]

Re: ECM and Distributor

Sorry 1st day back from vacation.

1999 7.4 MPI

I was thinking more about the distributor.

 

[Don S]

Re: ECM and Distributor

You have an EST distributor, do being 1 tooth off would mean you would just have to turn the distributor further to get it run.
Being as it is a 99, have you ever had the injectors cleaned and tested?
You stated you had low vacuum. When, explain.
Do a new compression test and post the results.

 

[HFXJACK]

Re: ECM and Distributor

You have an EST distributor, do being 1 tooth off would mean you would just have to turn the distributor further to get it run.
Being as it is a 99, have you ever had the injectors cleaned and tested?
You stated you had low vacuum. When, explain.
Do a new compression test and post the results.

This is an ongoing issue from previous posts. The engine is a reman from Michigan Motors. Compression is 170 across the board. Vacuum is 10" at idle 16" at 1400 rpm. We checked for vacuum leaks with propane and pressure tested the lines. if you pump up the vacuum manually to 18" engine runs fine. Map sensor and tps is new. ICU was replaced with one known to work. ECM has been replaced. New fuel pressure regulator. I have 40PSI at Idle because of low vacuum. Injectors were tested and cleaned. Timing is 8 degs at idle. Engine rpm changes when put in test mode. No code errors. Some people suggesting Cam is off by a tooth I am having trouble with that opinion.

Thanks

 

[mpdive]

Re: ECM and Distributor

Any warranty on this reman? I would be hard pressed to make any modifications to this engine to compensate for incorrect cam positioning. Are you sure the timing is set to specs? Just asking

 

[HFXJACK]

Re: ECM and Distributor

Michigan Motorz said send it back and they will investigate. However that means pulling the boat, pulling the engine, shipping engine complete to them from Vancouver Canada and then return to me to repeat the process. It would be cheaper to discard the engine and start over. I may have to pull the boat and lift the engine to check the cam from here certainly cheaper than the freight and storage cost. I do not want to think that their quality assurance is such that to date I have spent over 8K proving they are not the problem.
It has be 6 months since I purchased the engine. I have lost an entire year of boating spent more than 8K and no further ahead than I was in the beginning. During this time I spoke to Michigan Motorz on several occasions as did the mechanics working on the problem sometimes several times in a week. Then after a lapse of 3 weeks I call the same contact again and he has no memory of me or my problem. Now I ask if you have dealings with one of your customers from a city you do little business in with an issue that to them seldom happens and your speaking to this person 2 or 3 times a week and after 3 weeks you have memory of that person or the problem. Makes you feel kind of lonely and abandoned.
All I want to do is find a solution to the problem and go boating.

 

[Don S]

Re: ECM and Distributor

Ok, time to deal with the real world here.
They ask you to send it back and they would check the timing. What do you expect when buying a long block from a different country that doesn't have a dealer network like Mercruiser. What do you think they should do?

I have lost an entire year of boating spent more than 8K and no further ahead than I was in the beginning

Does this mean you replace the long block for the same reason?

Basically, you can pull the engine and send it back so they can check it out, or you can pull the engine, pull the pan and timing cover, and check the gears for their timing which is probably fine or you wouldn't be running as well as it is.
Once you know the timing is right, you know the problem is not valve timing........... Then where do you go?

 

[HFXJACK]

Re: ECM and Distributor

Ok, time to deal with the real world here.
They ask you to send it back and they would check the timing. What do you expect when buying a long block from a different country that doesn't have a dealer network like Mercruiser. What do you think they should do?



Does this mean you replace the long block for the same reason?

Basically, you can pull the engine and send it back so they can check it out, or you can pull the engine, pull the pan and timing cover, and check the gears for their timing which is probably fine or you wouldn't be running as well as it is.
Once you know the timing is right, you know the problem is not valve timing........... Then where do you go?

Don, I am a big boy and new the risk of buying a long block out of the Country I really don't think there is anything wrong with the engine and certainly would inspect the cam here. You ended your post with exactly the question I have been asking "Where do I go from here" Why is my vacuum at idle only 10"? A question that no one seems to be able to answer.

 

[mpdive]

Re: ECM and Distributor

I have a hard time thinking a rebuilder would make a mistake like that. Are you sure there is no exhaust restrictions? Is it bogging down on acceleration?

 

[John_S]

Re: ECM and Distributor

If you have the cam specs from MM, you might be able to put a degree wheel on it and a dial indicator to determine if it is one tooth off. Otherwise, if there isn't room to remove timing cover on that BB in the engine has too be at least lifted.

Have you already replaced the intake gaskets? I am not familiar with BB, but are you seeing any traces of oil being sucked into intake?

A quick search of your posts, does show a long list of issues.

 

[HFXJACK]

Re: ECM and Distributor

No Past 1K it is a great working engine all the way to WOT.

 

[HFXJACK]

Re: ECM and Distributor

I tried to get the Specs from MM they say they do not have this info. They say they only use OEM equipment. I did find the specs for the cam on the net. To check need to lift engine. This is a last resort when all options checked. Really do not think there is a MM engine issue. Have not replaced gaskets other than when rebuilt. Did do leak test with propane and water and pressure tested the lines. No leaks were found.

Thanks

 

[Don S]

Re: ECM and Distributor

When the engine is running, at idle, and up to operating temperature, what is the ECT reading on the diagnostic tool? Use an IR temp gun and check the base of the ECT sensor at the same time. Do they read the same or close to it?

 

[HFXJACK]

Re: ECM and Distributor

Thanks Don
That was checked they were very close in the readings. Replaced MAP and TPS and fuel pressure regulator and check Knock. if we put a pump on the vacuum line and increase vacuum to 18" the engine settles down and runs normally if that helps.

 

[Don S]

Re: ECM and Distributor

if we put a pump on the vacuum line and increase vacuum to 18" the engine settles down

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. ________

3. ________

4. ________

 

[HFXJACK]

Re: ECM and Distributor

Sent this off to my mechanic. I know they did some pressure tests but I do not have all the info. My primary fuel pump was replaced about 3 years ago the fuel pressure regulator is new. Will get back to you when I get the rest of the info.

John

 

[Tail_Gunner]

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

 

[HFXJACK]

Re: ECM and Distributor

Is it a 4 digit # on top rear of unit?
MM say they only use factory cams so should be able to get specs elsewhere since they said they do not have them. Going to boat tomorrow will get code
Thanks