Hard to re-start 4tec

[68ragtop]

Hi guys! Thanks to many of you that have been helping me out with my 2002 GTX 4-tec project. I am happy to say, the ski is done & running. I had it out on the water Sunday. The machine runs nice, but is having what I would call a pre-ignition problem on restarts when it is up to operating temperature. Cold & warm starts is fine, but after a few passes on the water, the engine bucks the starter on the compression stroke. Is this at all common with 4tecs? I am not sure how old the gas is, as the tank was full & I was told it was on the water this spring. So it could be fuel from last season. Battery is new, & passes tests. I did try another good battery to confirm that wasn't my issue. From what I see in the service manual, it would appear everything is control by the computer, & is non adjustible. I suppose the engine could be running hot? But again, nothing is shown on the info screen to indicate that.

From here, The only thing I can think to try is to drain & replace the fuel with non-ethonal 92, & maybe drop the plug temps from 8's to 9's to see if lowering the combustion temperatures helps at all.

Nothing out of the norm displayed on the info center, codes or otherwise.

Any thoughts?

 

[Sportster-2001-951C-Stock]

Looks like you found root cause for why the starter/ring were wiped out. Too much ignition advance maybe? Not sure how they set it up, software needs upgrade?

Yeah, make sure it's not running hot, that wouldn't be good.

 

[68ragtop]

That thought had crossed my mind too. When I realized the pump was all but detroyed, I started to think maybe the pump had locked up & they were trying to start it. It had defiinaltly been run with no bearing in the drive as the impeller shaft & wear ring was ruined too. I may see if I can get a hold of the PO & see if he would give me any history.

I guess this is one of the fears of getting away from my older late 90's 2-strokes. Somethings will be dealer only, & that would really rub me the wrong way....

 

[Sportster-2001-951C-Stock]

A motor kicking back will definitely put the hurt on a starter. Sometimes I find mercruisers with broken starter noses (GM starters) from that. Hydrolocking causes mounting frame warpage, go through a lot of starters over here from that.

Make sure it's got the right plugs in it, but does it only happen on an immediate hot restart or if you wait a few minutes? Could be overheating too, so I'd definitely check that, too hot makes mercruisers hard to turn too, that could be it.

Dunno if seadoo upgraded s/w for this issue, wouldn't surprise me, seems someone said something about too much initial advance and cranking issues but I thought that was early 951, dunno much 'bout 4-tec.

 

[68ragtop]

Make sure it's got the right plugs in it, but does it only happen on an immediate hot restart or if you wait a few minutes? Could be overheating too, so I'd definitely check that, too hot makes mercruisers hard to turn too, that could be it.

Yep, has the 8's in it now. however the electrode straps are a very light tan to gray, & the insulators are nearly white. the straps stay light colored to the base where most engines will darken up higher at the curve. So this seems a bit hot to me, Not sure what a normal running plug looks like on a 4tec. Piston crowns look good.

The thing has what I would consider very high compression for a 87 octane running engine. Now that its been run I have found 178, 185, 180. Again, not sure what is normal. based on my research, they appear to be all over the place.

Dunno if seadoo upgraded s/w for this issue, wouldn't surprise me, seems someone said something about too much initial advance and cranking issues but I thought that was early 951, dunno much 'bout 4-tec.

It is possible that its running a bit hot too. I am not sure what temp it should be at. It didn't appear that there was any air bleeding procedure in re-filling the coolant system. I did bleed the heat exchanger, but no trapped air of bubbles there.

I'll do some more research too. I am on a quick learning curve with the 4-tec. Its been fun so far as all of this is my hobby, but definitely out of my comfort zone being a 2-stroke guy when it comes to power sports.

 

[Sportster-2001-951C-Stock]

Yep, has the 8's in it now. however the electrode straps are a very light tan to gray, & the insulators are nearly white. the straps stay light colored to the base where most engines will darken up higher at the curve. So this seems a bit hot to me, Not sure what a normal running plug looks like on a 4tec. Piston crowns look good.

The thing has what I would consider very high compression for a 87 octane running engine. Now that its been run I have found 178, 185, 180. Again, not sure what is normal. based on my research, they appear to be all over the place.



It is possible that its running a bit hot too. I am not sure what temp it should be at. It didn't appear that there was any air bleeding procedure in re-filling the coolant system. I did bleed the heat exchanger, but no trapped air of bubbles there.

I'll do some more research too. I am on a quick learning curve with the 4-tec. Its been fun so far as all of this is my hobby, but definitely out of my comfort zone being a 2-stroke guy when it comes to power sports.

Yeah, the ceramic insulators on most 4 strokes are always white seems like, you might find a soot ring way down inside near the ceramic/metal transition, maybe not even.

If there's an air bleeder, it should be right near or just above the recirculating pump, to burp the air out of the impeller housing. But if it's got air in the recirc pump housing it will overheat rapidly and you'll know it(my guess). Heat exchanger might have trash in it?

Ground strap electrode should have a color change about half way from the end, yeah, near the curve, (My guess too).

That compression might be on high side for 87, agree, knock sensor should ring if pinging. Compression balance difference is probably okay(my guess). Might try bumping up octane and see, maybe PO was always using cheap fuel and cranking kick back was happening for a long time. Sure is easier just to reduce timing during cranking, stalling/kicking back on starter motor isn't good. Wonder if MPEM needs a signal to reduce timing, would think that would be start button logic though, LOL..

 

[68ragtop]

I think for now, I will drain out all the existing fuel. who knows how old, or what grade it is? While it might not be needed, I think I will throw a set of 9's in it as well & see what happens. I also cringe when a starter bucks. Especially on this ski after just repairing it.

Not sure when I will be able to test it. Days are going to be getting cold here soon..... I am already thinking about my sleds....

 

[Dennis]

Your plug description seems normal for 4tec. I dont see where you have any other choice but to see if new, higher octane fuel solves the problem.

My guess is that the jet pump was locking up and that is what damaged the flywheel.

The 4TEC engine typically runs at about 195 degrees when warmed up. Temp sensor goes off at around 210 degrees.

I'm not aware of any base timing adjustments that can be made with a scanner.

There is no place to bleed the engine cooling system. Any air bubbles circulate with the coolant thru the smaller hose going to the coolant tank.

 

[dbdave]

Your description of the plugs you are using has raised a flag for me. You refer to 8s and 9s which is usually a description of the NGK plugs used in the 2 strokes. (BR8ES or BR9ES?) The 4 tech takes an entirely different plug and they have very few issues. I just thought I'd ask for clarification.

 

[68ragtop]

Your description of the plugs you are using has raised a flag for me. You refer to 8s and 9s which is usually a description of the NGK plugs used in the 2 strokes. (BR8ES or BR9ES?) The 4 tech takes an entirely different plug and they have very few issues. I just thought I'd ask for clarification.

I was just referring to the heat range. DCPR8E, vs a colder DCPR9E

 

[68ragtop]

There is some hope to it being fuel related. I drained the tank empty tonight & it really had that "old gas" smell to it.
No way its from this year. I'll fill it up this weekend & see what happens. Supposed to be a whopping 50 degrees here on sunday

 

[ski-d00]

4tecs are very sensitive to old fuel. there are no software updates for the 2002 Siemens 030 ECU. no way to adjust timing electronically. you can adjust your timing gear slightly and this will bring down the compression significantly and it will run smoother. 4tec compression can vary greatly and will run great at 120-140 psi.

when you set your timing gear, did you rotate the motor by the crankshaft a couple of turns in running direction and check it again with the chain tensioner installed? this is important to get the slack out of the chain on the non-tensioner side. seen this several times by people putting 4tecs together for the first time.

 

[68ragtop]

Thanks for the post!
I never needed to pull it that far apart. Just removed the PTO cover & replaced the flywheel. I did question the position of the magneto, But I saw no index marks on it, or reference in the manual. However, I do believe I installed it in the same position it was removed.

Thanks again,

 

[68ragtop]

I brought it down to the boat landing this morning. No change.......

I drained & filled the tank with 92 octain fuel.
replaced the plugs with the DCPR8E's as the 9's were a special order.
Engine temp at the hoses was 160-170ish
Outside surface of the head temperature, 190ish

I have ruled out the battery, as I have tried another good one.
If I unplug the ignition coils, it will still crank hard, so its not from too high of ignition timing (unless the timing is causing it to run hotter)

So either the starter has an issue, or the compressed fuel is causing the problem.

Doesn't seem like a starter issue to me tho. IS there anything else that could cause it too run lean & create more heat than would be there otherwise?


Not sure what else I can do. I am stumped & I don't like it

Here' a short movie. You can hear the engine turn backwards when I let go of the start button on the second attempt Then it cranks fine & starts. It only does this when the engine is up to full operating temp. Cranks & Starts normal otherwise.

The voltage durring cranking is 10.6V 12.6 otherwise.

http://www.automationsystems.ws/misc/hardstart.MOV

68RT

 

[ski-d00]

the extra beeps during the warm restart make it appear to be an electrical issue. your ECU is resetting because it's either drawing high current from the starter when it's hot or your battery isn't supplying enough current when it's hot or the high compression when it's hot is drawing too much current and drops it below it's voltage threshold. try using a good car battery on a warm restart, something that can supply plenty of current when warm. you should also check your timing gear timing position, takes like 10 minutes.

 

[68ragtop]

the extra beeps during the warm restart make it appear to be an electrical issue. your ECU is resetting because it's either drawing high current from the starter when it's hot or your battery isn't supplying enough current when it's hot or the high compression when it's hot is drawing too much current and drops it below it's voltage threshold. try using a good car battery on a warm restart, something that can supply plenty of current when warm. you should also check your timing gear timing position, takes like 10 minutes.

Yes, the ECU does reset sometimes from low voltage. With my meter on the battery, the voltage will sometimes drop below 9 volts when the cranking comes to a stop. I did have an additional battery jumped with the one in the ski & this prevented the computer restarts, but it still cranked hard. Its drawing some high amperage when the starter is hanging up on those hot cranks. I can check the valve timing. I will need to order the locking pins first though, don't own those yet as this is my first 4tec. So you thinking maybe the valve train is too advanced?

 

[ski-d00]

you don't need the locking tools, all you have to do is get #3 to TDC and check the lines on the timing gear.

you can use the end of a drill bit for the cam locking tool but it's pretty easy to see the flat spot anyway.

 

[68ragtop]

you don't need the locking tools, all you have to do is get #3 to TDC and check the lines on the timing gear.

you can use the end of a drill bit for the cam locking tool but it's pretty easy to see the flat spot anyway.

Good enough, I will use my dial indicator on #3 to find TDC.

Weird thing is, this ski supposedly had run great until the impeller locked up, followed by the loss of the flywheel. According to the P.O. anyway. I was starting to think maybe they overheated the starter, but I would think if the starter was bad, it would crank hard all the time, not just when its up to full operating temps.

 

[Sportster-2001-951C-Stock]

At this point I vote for a bad starter winding, based on the jet pump was seized. Unfortunately the damn things are expensive, and I hear aftermarket starters are hit and miss....

Is there an alternator shop around there that can maybe put that starter armature on their growler?

http://en.wikipedia.org/wiki/Growler_(electrical_device)

 

[68ragtop]

We used to have a Auto parts store here in GreenBay that had everything. It was an old school parts supplier & machine shop. They rebuilt starters, alternators, brake calipers, etc. I would always go to that that business to buy my auto parts. You walked through the door & it was like a time machine. They were in business for nearly a century. They even had parts on the shelf for the late 50's early 60's generators.

Sadly, Like so many independent small business's, they succumbed to the large automotive chain stores & eventually couldn't make a profit. It was a sad day for me when they closed their doors about 5 years ago. They would have tested that armature without question. Absolutely loved that place.


Back to the topic though, I would image if it had a shorted winding it would probably still have a heavy currently draw under load, just not the same output. If the starter did turn out to be the culprit, that would mean that its normal for these engine to meet resistance on a hot compression stroke, but the starter overcomes it quick enough so its not too noticeable.

Are there any pictures of a 4-tec piston crown from a properly running ski on this site? This engine does have a decent amount of carbon deposits on them. Not sure if they could be getting hot enough to cause early combustion? I can post some picts to compare.

Thanks for hanging in there with me

 

[68ragtop]

Checked the cam timing. It seems to be correct. Using my dial indicator, I found TDC on #3, Only had to turn the crank a smidge where the piston dropped -/+ .001" off TDC & the alignment pin slid in on on the cam. So I would say the cam is probably retarded less than 1 degree.

Going to have the armature tested for shorts tomorrow.

68RT

 

[68ragtop]

Armature tested good. Only suspect thing left is the carbon build up on the crowns of the Pistons. Not sure if that could be raising the compression, or getting hot enough to lite the compressed fuel mix. I sure wish I could just easily pull the head & manaully clean them up. All I can do is look at it through the spark plug holes....

 

[Sportster-2001-951C-Stock]

Well, that figures.........

 

[68ragtop]

Well, that figures.........

Pretty much....

Well, I decided to buy a used oem starter, even though mine checks out, & I don't think it needs one, At least I can officially rule it out. I also recoded some video from the borscope. I'll see if I can post it too see if you guys think if excessive carbon could be causing a preignition problem. No question it has a lot of carbon build up, Just not sure if it could cause a hot spot.

Can the head be pulled on these with the intake & exhaust manifolds still intact? Just curious.......

 

[Dennis]

You can leave the exhaust manifold on but the intake plenum must be removed.