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jonmichael
07-13-2013, 11:01 AM
I have a 2000 Maristar with the LTR engine. My mechanic just fixed the blown head gasket and now it wont fire. He changed all of the fuses after he shorted them out. He said he has checked all of the sensors. He said that he has checked the voltage on everything and narrowed it down to the ECM Does anyone know where I could send this ECM to have it tested before I buy a new one?i. I really think he is missing something simple. I dont see how you can have a blown head gasket and a fried ECM at the same time. It was firing when i took it into the shop. Anyones help would be greatly appreciated

JimN
07-13-2013, 11:11 AM
I have a 2000 Maristar with the LTR engine. My mechanic just fixed the blown head gasket and now it wont fire. He changed all of the fuses after he shorted them out. He said he has checked all of the sensors. He said that he has checked the voltage on everything and narrowed it down to the ECM Does anyone know where I could send this ECM to have it tested before I buy a new one?i. I really think he is missing something simple. I dont see how you can have a blown head gasket and a fried ECM at the same time. It was firing when i took it into the shop. Anyones help would be greatly appreciated

He shorted all of the fuses? I can think of one way to do that and it doesn't involve doing anything correctly. If the ECM is bad (and this would probably kill the IC module, too), it's possible that the battery cables were connected pos to neg/neg to pos and the key was turned to ON. If that happened, he's going to have a bad day when the bill for the ECM and IC module comes.

Indmar, MC, OBD Diagnostics can check it out.

jonmichael
07-13-2013, 04:13 PM
I am not sure which fuses were shorted. I know the kill switch and the drive sensor fuses were. It was firing when I took it in due to water in the oil. I know he did not get the battery cables hooked up wrong. Could he have fried the ECM when he was hooking the wires and plugs back up?

JimN
07-13-2013, 04:29 PM
I am not sure which fuses were shorted. I know the kill switch and the drive sensor fuses were. It was firing when I took it in due to water in the oil. I know he did not get the battery cables hooked up wrong. Could he have fried the ECM when he was hooking the wires and plugs back up?

If he connected the sensors and ECM while the battery was connected, no fuses should have blown. The ECM doesn't necessarily like this, but it's not usually a death sentence. The harness has three fuses- one for the fuel pump, one for the ECM labeled 'System' and one for the ignition system. If any fuses blew, something was shorted (fuses don't blow because they shorted, it would be a device or the wire fed by the fuse. If all three blew, it's possible that a main ground wire was left off and touched something that was electrically hot.

Regardless, this isn't the place to look for answers- I would be grilling the person doing the work. All we can do is guess because we weren't there when it happened and we aren't where the boat is now.

What does "I know the kill switch and the drive sensor fuses were" mean? The wires fried? What do you mean by 'drive sensor'? Which engine- LTR or TBI?

mikeg205
07-13-2013, 04:45 PM
+1 for what JimN says... I'd be saying - what the hell do you do to blow the fuses??? Traxxx here just got his head gasket changed and nothing electrical got fried. Your mechanic is on the hook to get this fixed. The only fuse I ever blew was the fuel pump. It happened when I tested a new fuel pump that I bought as a spare. Got a new pump tested again... fuel pump spun - fuse did not blow.

I'd be asking a lot of questions - mechanic should have known better... JMO

mikeg205
07-13-2013, 04:46 PM
+1 for what JimN says... I'd be saying - what the hell do you do to blow the fuses??? Traxxx here just got his head gasket changed and nothing electrical got fried. Your mechanic is on the hook to get this fixed. The only fuse I ever blew was the fuel pump. It happened when I tested a new fuel pump that I bought as a spare. Got a new pump tested again... fuel pump spun - fuse did not blow.

I'd be asking a lot of questions - mechanic should have known better... JMO

BTW - what caused head gasket to fail? Overheat? - If yes - what was cause.. ?

JimN
07-13-2013, 05:00 PM
BTW - what caused head gasket to fail? Overheat? - If yes - what was cause.. ?

I'll add to this question about overheating- if it overheated badly enough, it's possible for the harness to melt if it comes into contact with heads, intake or exhaust manifolds. If this wasn't inspected and the wire insulation melted badly enough, the wires could short, causing multiple problems. If someone repairs an engine and doesn't do a basic visual inspection, they're not being very thorough.

jonmichael
07-13-2013, 11:10 PM
My brother was diving the boat and said it never overheated. After they floated for awhile the boat would not start. I checked the oil and it looked frothy, my auto mechanic was there and told me that it was a cracked block or blown head gasket. He said to bring it in and he could fix it.I went out the next morning and the boat fired right up, I then took it to my auto mechanic.He called me in 2 weeks and said their was moisture in the #1 cylinder and he had sent the heads to the machine shop. They came back fine and he said it was a head gasket and that he would fix it. He then called me a couple of weeks later and said that he fixed the gasket but could not get it to fire. I went to his shop and noticed that the kill switch was not working. He said he would check the fuses and try it again. He replaced the kill switch fuse and ordered a part from GM( I forgot what it was called). He called back a few days later and said it still would not start but had a FORMER boat mechanic come look at it. He said all of the sensors were good and they replaced a the ECM fuse not drive sensor(Sorry about that). Still would not start and he said it must be a ECM problem. I called Fort Worth mastercraft and they said they could not test the ECM there but gave me a website and number to call. They said that there were 2 plugs that commonly get reversed when they are plugged back in, they said try that before messing with the ECM. He has tried that and it still does not start. I am stressing about whether I should pay him for what he has done and take it to the dealership or leave it to him to get it fixed. I am thinking my next move is to send the ECM to Indmar to have it tested. I am not mechanical as you can tell and I know that I messed up not taking it to mastercraft. Do you think I should just bite the bullet and take it to a boat mechanic or leave it to him to get it fixed? I am guessing I owe him around a thousand right now. All of the ECMS i have found are around 1500. Sorry about the long post, you guys are a great help. I wish i have found this forum 8 years ago when i bought the boat. The engine is a LTR

mikeg205
07-14-2013, 12:42 AM
head gaskets fail 2 ways in my understanding... over heat or defect... but that is my understanding... the bad gasket would never prevent the engine from firing. Reads like the auto mechanic did not know how to rewire - I would check all harnesses. No reason for fuses to blow randomly... Something is very wrong and is the fault of mechanic IMO.

I would inspect all harnesses... by-pass safety lanyard and give it a try.

Are you able to read the ECM at all?

JimN
07-14-2013, 01:03 AM
My brother was diving the boat and said it never overheated. After they floated for awhile the boat would not start. I checked the oil and it looked frothy, my auto mechanic was there and told me that it was a cracked block or blown head gasket. He said to bring it in and he could fix it.I went out the next morning and the boat fired right up, I then took it to my auto mechanic.He called me in 2 weeks and said their was moisture in the #1 cylinder and he had sent the heads to the machine shop. They came back fine and he said it was a head gasket and that he would fix it. He then called me a couple of weeks later and said that he fixed the gasket but could not get it to fire. I went to his shop and noticed that the kill switch was not working. He said he would check the fuses and try it again. He replaced the kill switch fuse and ordered a part from GM( I forgot what it was called). He called back a few days later and said it still would not start but had a FORMER boat mechanic come look at it. He said all of the sensors were good and they replaced a the ECM fuse not drive sensor(Sorry about that). Still would not start and he said it must be a ECM problem. I called Fort Worth mastercraft and they said they could not test the ECM there but gave me a website and number to call. They said that there were 2 plugs that commonly get reversed when they are plugged back in, they said try that before messing with the ECM. He has tried that and it still does not start. I am stressing about whether I should pay him for what he has done and take it to the dealership or leave it to him to get it fixed. I am thinking my next move is to send the ECM to Indmar to have it tested. I am not mechanical as you can tell and I know that I messed up not taking it to mastercraft. Do you think I should just bite the bullet and take it to a boat mechanic or leave it to him to get it fixed? I am guessing I owe him around a thousand right now. All of the ECMS i have found are around 1500. Sorry about the long post, you guys are a great help. I wish i have found this forum 8 years ago when i bought the boat. The engine is a LTR

There are specific steps that are used to diagnose a crank/no fire problem and it's the same for this engine as it would be if it was in a GM car or truck. There's a purple/white wire that sends RPM info to the ECM and if he hasn't tested that fro 1-2VDC while cranking, he needs to read a GM manual. It's a GM engine and even if it is the LTR, the differences are mainly in the intake plenum (the big metal part that has MC on it, on top of the engine), raw water cooling and the exhaust. The rest is basic GM stuff.

I would hesitate to replace the ECM just because it won't fire. I would, however, check the routing for all of the sensor wiring, make sure the plugs on the harness are seated well, etc.

I asked what you meant by the "drive sensors"- I assume you meant crank sensors, on the block next to the crankshaft pulley and these are the ones that are sometimes reversed. These have no fuse of their own and reversing won't cause fuses to blow. I would also make sure the harness isn't being pinched by something that bolts down.

The fact that the crank sensors may have been reversed tells me that the mechanic didn't label anything when he disassembled the engine and removed the harness. That's a huge problem since he's not familiar with this engine and I would start asking some questions about when he last worked on one of these. While I know "there's a first time for everything", I really don't like the thought that when someone is charging for it when they do something like this for the first time. "Earn while you learn" is a bad way to do business and the customer usually gets hosed.

If you haven't received an estimate for the work, get one ASAP. You just might be his retirement package, without realizing it.

jonmichael
07-14-2013, 01:42 PM
I bypassed the kill switch but still wont crank. My boat was sitting out in the rain with the front of the motor totally exposed including the ECM which was hooked up. I texted the mechanic about him leaving the engine and ECM exposed to the rain, I wanted to find out if that would damage it. I have never recieved a return text. I know I should just go get the boat but I dont want to take the responsibilty off him. I know mechanics carry insurance, I would think this needs to be claimed on it. Thanks again for your help

JimN
07-14-2013, 03:17 PM
I bypassed the kill switch but still wont crank. My boat was sitting out in the rain with the front of the motor totally exposed including the ECM which was hooked up. I texted the mechanic about him leaving the engine and ECM exposed to the rain, I wanted to find out if that would damage it. I have never recieved a return text. I know I should just go get the boat but I dont want to take the responsibilty off him. I know mechanics carry insurance, I would think this needs to be claimed on it. Thanks again for your help

Is the problem that it won't crank, or it won't fire? Two different things. Cranking means the starter is engaged and turning the engine and 'fire' means the spark plugs are providing spark.

If it's not cranking, jiggle the shift between neutral, forward and reverse. If you want to look for the cause, you should see two white wires attacked to a piece that looks a bit like the base of a spark plug, with two brass screws. If each white wire isn't attached to one of the screws, it CAN'T crank.

In the even that it won't fire, there's a specific group of steps used to diagnose the possible problems.

If it won't crank OR fire, make sure the plug between the engine harness and boat harness are plugged together correctly and completely. If this was rotated and forced together, it will have problems.

If the mechanic left your engine in the rain, the ECM should be OK unless the harness was unplugged and water got into the receptacles.

Insurance covers accidental damage, not negligence or lack of knowledge about something. Is this guy an established mechanic, or just someone who occasionally works on boats? You may be in for a battle.