ski-d00
Well-Known Member
The plug always has to be grounded to complete the circuit regardless of a coilpack system or old school plug wires.
-
This site contains eBay affiliate links for which Sea-Doo Forum may be compensated.
Bad starter or not enough battery/amps to turn rebuilt engine?
- Thread starter mini4mw
- Start date
I'm going to pull the engine again and break it down to the crank and pistons (pull oil pumps, valve train and bottom of the case) and see if I can tell why its so hard to turn over. I can keep messing with trying to get it started ( I do get a few firings from plugs when trying) but usually the battery is dead after 2-3 attempts. I figure if its hard to turn over there may be some other issue internally and if I did get it running it may just cause more damage. So off to pulling it apart. Its cold now and I'm tired of messing with it so I'll probably take a month or two off and get back on it. I'll keep it bookmarked to update later.
So I haven't pulled engine yet, just thinking and testing infrequently because I don't want to pull it and turn out to be some other issue.
Lately I've just been testing different electrical pieces.
Tested spark - nice and bright
Tested injector resistance - 13ohms, in spec
Tested voltage on positive lead to injector, 13.3v
I also tested compression and have 120psi on each cylinder w/o the supercharger in.
However, I also tested the negative lead on the injector and I'm seeing 2.6v on each injector negative lead. Volt meter negative to battery negative. DSS key on. Positive lead to the negative terminal on the fuel injector connector (which goes to ECM).
Reading through wiring diagrams, MPEM sends 12v + to spark plug/coil and injector. MPEM also sends 12v+ to ECM. ECM control the ground to the spark and injector to complete a circuit and turns the ground on/off as needed to make the engine run. Little more reading says if the negative side has voltage the ECM is leaking positive voltage and may be faulty. However, I did have the MPEM and ECM tested and they were both good. This is when the fuel pump was found to be turned off in one of the units.
Anyone worked on something like this and have experience/input?
Thanks-
Lately I've just been testing different electrical pieces.
Tested spark - nice and bright
Tested injector resistance - 13ohms, in spec
Tested voltage on positive lead to injector, 13.3v
I also tested compression and have 120psi on each cylinder w/o the supercharger in.
However, I also tested the negative lead on the injector and I'm seeing 2.6v on each injector negative lead. Volt meter negative to battery negative. DSS key on. Positive lead to the negative terminal on the fuel injector connector (which goes to ECM).
Reading through wiring diagrams, MPEM sends 12v + to spark plug/coil and injector. MPEM also sends 12v+ to ECM. ECM control the ground to the spark and injector to complete a circuit and turns the ground on/off as needed to make the engine run. Little more reading says if the negative side has voltage the ECM is leaking positive voltage and may be faulty. However, I did have the MPEM and ECM tested and they were both good. This is when the fuel pump was found to be turned off in one of the units.
Anyone worked on something like this and have experience/input?
Thanks-
More testing today. I need to put up a video that will help explain, but I'll try in words.
Bought a cheap injector test kit from amazon that runs the injectors off a spray bottle. I used carb cleaner. Tested all 3 injectors and they worked fine at a slow on/off (or as fast as test kit goes). I went ahead and replaced the microfilters in the injectors.
(Note I tested spark the other day and it was great)
I put the injectors back on the fuel rail and left them pointing up. I started the engine.
1st try: all 3 injectors fired immediately and then only 3 and 2 would cycle fuel for ~3 seconds and then none would fire even though the engine is still turning over.
2nd try: all 3 injectors fired immediately and then only 1 and 2 would cycle fuel for ~3 seconds and then none would fire even though the engine is still turning over.
3nd try: all 3 injectors fired immediately and then only 1 and 2 would cycle fuel for ~3 seconds and then none would fire even though the engine is still turning over.
It would then just repeat this. Normally all 3 injectors fire immediately, then two will fire with cylinder rotation, but the 3rd would never fire. The 3rd one that does not fire would switch between cylinders 1 and 3 periodically.
I did not have coils or spark plugs in during this test.
Thoughts? Why does it stop firing gas after a few cylinder cycles even though I am still pressing the start button and the engine is turning over? Why would either cylinder 1 or 3 not fire fuel after the initial fire of all 3 injectors?
Bad ECM or CPS (crankshaft position sensor)? Bad CPS I'd think would cause it to not fire fuel or spark at all, or at least not what appears to be a proper timing/sequence of two cylinders/injectors.
I'll post a video later and share the link.
Oye...
Bought a cheap injector test kit from amazon that runs the injectors off a spray bottle. I used carb cleaner. Tested all 3 injectors and they worked fine at a slow on/off (or as fast as test kit goes). I went ahead and replaced the microfilters in the injectors.
(Note I tested spark the other day and it was great)
I put the injectors back on the fuel rail and left them pointing up. I started the engine.
1st try: all 3 injectors fired immediately and then only 3 and 2 would cycle fuel for ~3 seconds and then none would fire even though the engine is still turning over.
2nd try: all 3 injectors fired immediately and then only 1 and 2 would cycle fuel for ~3 seconds and then none would fire even though the engine is still turning over.
3nd try: all 3 injectors fired immediately and then only 1 and 2 would cycle fuel for ~3 seconds and then none would fire even though the engine is still turning over.
It would then just repeat this. Normally all 3 injectors fire immediately, then two will fire with cylinder rotation, but the 3rd would never fire. The 3rd one that does not fire would switch between cylinders 1 and 3 periodically.
I did not have coils or spark plugs in during this test.
Thoughts? Why does it stop firing gas after a few cylinder cycles even though I am still pressing the start button and the engine is turning over? Why would either cylinder 1 or 3 not fire fuel after the initial fire of all 3 injectors?
Bad ECM or CPS (crankshaft position sensor)? Bad CPS I'd think would cause it to not fire fuel or spark at all, or at least not what appears to be a proper timing/sequence of two cylinders/injectors.
I'll post a video later and share the link.
Oye...
ski-d00
Well-Known Member
There is a wining noise while cranking that makes It sounds very labored like there is a drag on the system. When you put the engine together before the timing chain was put on, did it turn over freely with just the minor drag of the pistons that should be coated with oil? It should be turning over faster than it is, while cranking can you see what the rpm reading is?
The ECU is very smart meaning it knows when it's cranking, running, etc., and if the coil pack circuits are completed. It will adjust injector timing and will stop injectors when it thinks it is getting flooded so it's very difficult to get exact sequence of injectors correct unless everything is connected correctly AND there are no codes that will put it into limp mode. During limp mode, it will not fire all injectors but sequence them to cylinders which is also how the learning key works as well at different RPMs so make sure not to ever test with a learning key.
The ECU is very smart meaning it knows when it's cranking, running, etc., and if the coil pack circuits are completed. It will adjust injector timing and will stop injectors when it thinks it is getting flooded so it's very difficult to get exact sequence of injectors correct unless everything is connected correctly AND there are no codes that will put it into limp mode. During limp mode, it will not fire all injectors but sequence them to cylinders which is also how the learning key works as well at different RPMs so make sure not to ever test with a learning key.
I put a jump pack on it and tried it again and the injectors and spark worked fine. The battery and jump pack would be dead after 3-4 tries of starting and normally it would start slow, like a dead battery to begin with, perhaps fire a cylinder or maybe two and then die. After 3 tries, both batteries dead. Going back through some old videos the pistons/rings went in easy, but still had to smack them with a mallet to get them in the right place. After working on it for several months I think the pistons are just too tight.
I pulled the engine today and broke it all the way down. Piston skirts had wear (much more than it should from just trying to start the engine) but the cylinders look fine. No scratches or anything I can feel with a finger nail. I'm going to take it to a machine shop and have them rub off .1-.2 mm in the cylinder sleeve and then put it all back together.
I pulled the engine today and broke it all the way down. Piston skirts had wear (much more than it should from just trying to start the engine) but the cylinders look fine. No scratches or anything I can feel with a finger nail. I'm going to take it to a machine shop and have them rub off .1-.2 mm in the cylinder sleeve and then put it all back together.
