New motor, new ECM no start

[Dave-R]

The 8.1 is different than other big blocks. Google it. I was also surprised.
Dave-R

 

[Matt9712]

Ya the Techmate verified the ECM is correct. But looking at the data trying to figure out why with key on and engine off the computer is showing the motor is at 92% load....... reading up on this it appears to be MAP sensor issue. Can't find anywhere that can say if this would cause a no start condition.

 

[Matt9712]

And while cranking the TPS voltage does not change and the engine load actually decreases.....

The TPS voltage changes when I move throttle though. So I think that is working the way it's supposed to

 

[Matt9712]

Can a MAP sensor create a no start condition? I've read that in certain applications it can control timing and fuel delivery.

Also what's the easiest way to test a FPR? I think I have multiple issues one being spark and one being fuel. When i turn key on and engine off I have 59-60 psi on fuel rail. As soon as pump shuts off after the couple second initial run when key is turned on my pressure immediately drops to 0. I have pulled the entire rail off and pressurized it with the fuel pump and proved the injectors are not leaking. I have no gas in the vacuum line ( which I've read is indicitave of faulty FPR) Just dont want to put another dime in this thing until I can prove it's a problem.

Thanks again for all your help so far

 

[alldodge]

Can a MAP sensor create a no start condition? I've read that in certain applications it can control timing and fuel delivery.

Never heard of this happening, maybe someone else has

Also what's the easiest way to test a FPR?

Remove and use air pressure via a regulator to see if it holds. Should be able to do it with the fuel rail and injectors installed. With regulator removed, apply pressure slowly until the regulator opens.

I think I have multiple issues one being spark and one being fuel. When i turn key on and engine off I have 59-60 psi on fuel rail. As soon as pump shuts off after the couple second initial run when key is turned on my pressure immediately drops to 0.

tpenfield has tested his (Merc) and something is bleeding the pressure off, what that is unknown as you know.

 

[Fun Times]

The Map sensor is the engine load sensor. A malfunctioning MAP sensor "typically" (Like an ignition coil Not always though) tends to make the engine experience more of a hard to start symptom vs no signs of starting issue....Plus it usually tends to make the engine run really rich with fuel noted by a heavy smell in the air coming from the exhaust system and fuel fouled spark plugs. https://www.yourmechanic.com/article...sor-map-sensor

Engines that do not have a Mass Air Flow (MAF) sensor, the MAP sensor signal is also used by the PCM to calculate engine load -- how hard the engine is working. This is called the speed-density method of calculating engine load for engines without MAF sensors. It is because of this engine load calculation for speed-density engines that the accuracy of the MAP sensor signal is so critical.

http://www.fastfieros.com/tech/map_s..._they_work.htm

Since the engine tends to run with no CAM Shaft connected, one would sure think the issue has got to be a hidden message within these findings because the engine actually "runs" even if it runs really bad and a short time-frame.

Since you have a scan tool now, I believe there is a method out now that you can adjust CAM Angle via turning the HVS distributor assembly to the exact area you need it to be to run correctly while watching the scan tool such as an example from the following quote from an Indmar service tech...

The distributor for a 2006-2008 model is called cam angle adjustment and you need a scan tool to check it. The specification is 705 plus or minus 5 at 1200 RPM or higher. On 2009-2011 models the distributor adjustment is called cam retard and the spec is 12 degrees plus or minus .5 at 1200 RPM. You need a scan tool to check the adjustment.

Check your new Rinda Tech users manual and see if it talks about CAM settings or try calling Rinda to see what they know.

Also iboats member Muc once mentioned Mercruiser Service Bulletin 2011-11R2 which talks about using a battery and diode to help set HVS Cam angle but it's not available online... Only by a Merc dealer. http://forums.iboats.com/forum/engin...0#post10221970

Not sure if this may help but it's interesting, Bench Testing Hall Effect Switches - Bimba Manufacturing

Try cranking the engine over a bit and see if some of those scan numbers change especially the CAM numbers. Sometimes depending on where the engine stops might give you funny reading since you're trying to scan "live data" from a non running engine so most of them readings are "sort of" invalid because some of them need to have the engine running to get a better reading of their true parameters.

 

[tpenfield]

Hello,

Just reporting in since I heard my name.

You could take out the regulator and test it, or just replace it. ( I think the V-P regulators are more than a dime though )

I am wondering it there is a fuel rail pressure sensor that is killing the ignition once the pressure drops to 0? Does the fuel pressure do the same thing if the engine is cranking?

 

[Matt9712]

I will definitely try the FPR testing this week.
The Rinda with everything I have read can read the cam angle but has to be running. I have seen it with key on and engine off and it shows a 0 cam angle but I'll check while engine is cranking to see if that will change during a cranking evolution. I think the readings will be a little skewed due to RPM's fluctuating and not a steady state though.

The hall effect sensor testing write up was really good. I plan on trying that tonight to verify if camshaft position sensor is faulty. It is brand new so I don't think it will be bad but I do hope that it is just to lead me to a smoking gun......

I haven't found anything in Seloc book that shows that it has a fuel rail pressure sensor. I wish it did

 

[Matt9712]

Ok some more updates...
. Bench tested my old camshaft sensor and new one.... couldn't get readings on either one. So I got new one and that didn't change anything.....

Cranked over engine while checking cam angle on scanner it stayed at 0....

Tried to perform injector test with scan tool ..... kept giving me an error and wouldn't do it for any injector. Which makes me believe it's a main feed to injector issue.

Tool out coil and ignition module going to bring to AutoZone tomorrow becaise i believe they can test them.

So question is...... what could be causing the no power to injectors other then relay? The ignition module does have something to do supplying power to them right?

Is there any sensor that would kill power to ignition injector relay? Other then a wiring diagram that shows colors of wires going to sensors I don't have any type of logic diagram as in what if any sensor would shut down certain things. I have no fault codes and other then seems to be a faulty MAP sensor by showing boat is at 90% load when not running I am grasping at straws......

 

[alldodge]

See if your getting 12V on the Pink and Pink/White wire of each injector

 

[Jason89sunbird]

You definitely have a wiring issue, pinched when installing or a ground issue... what you are calling a cam position sensor is actually an ignition module that gives a tach signal to the ecu. That is why when you unplug the 4 pin plug going to the ignition module it keeps firing the coil. Only an ignition module has the power transistors that can run a coil. I'm telling all this to help understand what is happening, By plugging in the 4 pin plug you are causing the ignition module to quit sparking. The part you need to concentrate on is the 4 wires from the ignition module to the ECU. If you have replaced both the module and the ECU with no luck then it has to be one of the 4 wires with an issue or power\ground to the ECU.

No power from the injector relay can easily be from the ECU not powering it up due to the fact it doesn't see ignition signal from the ignition module.

 

[Matt9712]

I will check the voltage on the injectors when I get off work today...

I definitely have a camshaft position sensor that's located in the distributor and an ignition module that's located next to the coil. The camshaft position sensor is only a 3 wire sensor and that is the one I unplug when coil will fire continuously. I have not tried to fire up boat with ignition module unplugged.
I don't have a pinched wire as I pulled out the entire wiring harness and untaped the entire thing to inspect each and every wire. I also don't feel it's a ground issue as I have checked every bolted ground resistance back to battery with less then 1 ohm resistance. I also checked all grounds in ECM connector to ground and those were all good as well.

 

[Matt9712]

Another thing of interest which I haven't checked since I installed new ECM. Early on when troubleshooting this no start issue. I found that while fuel pump is running i had 12v on B+ and 0v on ground at ignition relay but as soon as fuel pump shuts off I have 12v on B+ and 2.5v on ground. Which gives me 9.5v across relay which is not enough to keep it pulled in. According to my scanner it says boat is not in derate mode so doesn't look it's any type of protective scheme that ECM is in.

 

[alldodge]

12v on B+ and 2.5v on ground

I see it as: The ECM applies a ground which pulls the relay in and the pump runs. The ECM removes the ground and now its sort of floating. Until the ECM sees the coil firing, its not going to turn the pump back on

 

[Matt9712]

Had the ignition module and coil tested. They all tested good. Weather didnt let me test anything on the boat so hopefully tonight will be possible to check voltage.
I was looking for a new MAP sensor and the one installed on my boat is of a rare type which drives the price past the clouds...... so without knowing for sure it is an actual issue is it possible for testing purposes to swap with a car one? In research there are so many types ( 1 bar,2 bar, 3 bar.....) any idea what a boat is? Mine is a Bosch 0261230075 and I have to make a junkyard trip tomorrow so hoping i could just pull one off a truck there to test this. Most GM ones online don't look like the one I have.
Thanks

 

[alldodge]

It is a 1 bar sensor but also its the air temp sensor from what I'm finding
https://partinfo.org/bosch-0261230075/

but also crosses to GMC 12568929 and OE DSS2TF (found one for 11 on ebay
http://www.ebay.com/itm/BOSCH-02612...LD-PRESSURE-SENSOR-MAP-46553045-/122344822313

http://www.ebay.com/itm/NEW-MAP-Int...avy-Trucks-0-261-230-133-DSS2TF-/222447958531

If what I'm finding is correct

 

[Jason89sunbird]

I will check the voltage on the injectors when I get off work today...

I definitely have a camshaft position sensor that's located in the distributor and an ignition module that's located next to the coil. The camshaft position sensor is only a 3 wire sensor and that is the one I unplug when coil will fire continuously. I have not tried to fire up boat with ignition module unplugged.
I don't have a pinched wire as I pulled out the entire wiring harness and untaped the entire thing to inspect each and every wire. I also don't feel it's a ground issue as I have checked every bolted ground resistance back to battery with less then 1 ohm resistance. I also checked all grounds in ECM connector to ground and those were all good as well.

Sorry, I was confused on how your efi system was setup due to the wiring diagram ALLDodge posted, it has a small cap HEI with individual injectors. So you have a CMP sensor in the dist and a crank sensor behind the Harmonic balancer like a 1996-1998 chevy truck. On that vintage for the truck the crank signal tells the ecu to signal the ignition module when to spark. The CMP signal, times the firing of the injectors. If you have a bad (unplugged) CMP the truck will still run based off the crank signal. I'm not saying the boat ecu will do the same, I think it would but!!! That doesn't really matter, what matters is that the ecu doesn't like both of them connected when we are concerning spark. Since you have gone thru the wiring, replaced most everything and checked power and ground I would be looking at the crank reluctor wheel or is the CMP(disturbutor) installed correctly. here is a picture of a camshaft replacement, you can see the crank reluctor wheel in it, hope it helps

http://www.fourwheeler.com/how-to/en...00-v-8-engine/

 

[Matt9712]

Thanks for the info! I'll look into those sensors today. Had a bunch of stuff come up yesterday so didn't get to look at boat. But will spend the afternoon on it I'm sure ....

I have thought the reluctor wheel as well. Unfortunately it seems the harmonic balancer has to come off and the oil pan dropped a little but in order to get timing cover off to see the reluctor wheel. I also have thought about timing chain installed wrong. I ordered a long block so engine came with it already installed but more I have read it is another possibility. Anyone know of a way to verify timing chain is on correctly and timed right without going through all that? I have verified timing numerous times with cylinder 1 at TDC but if chain is tooth off I'm guessing it could be throwing the cam/crank timing off to ECM?

 

[alldodge]

Don't see the timing chain being off would keep it from firing. The CPS would still do its job, and the cam sensor would do there thing, only thing that would happen is it would fire with a valve in the wrong position.

 

[Matt9712]

I just figured since it would fire a couple times from coil then stop that maybe some sort of timing or signal was confusing the ECM. I looked at my old motor reluctor wheel and it's keyed so being on wrong doesn't look like a possibility. I guess it could've been put on backwards but that's another reason I wondered about timing chain off time. But definitely glad to hear that shouldn't be a possibility due to the amount of work would take to get to see it.