Challenger 2000 240 runs well without TPS??

[svtjoe98]

Hey guys,

Merry Christmas! I purchased a very neglected 2000 Challenger 2000 last year and have completely restored it. It showed almost zero salt water use ( I live and purchased it in Florida). I had to reinstall intake manifold, fuel pump (replaced pump in vapor separator). The engine has compression of 121psi on all cylinders (different gauge showed a little higher).

I had everything back together and it started great and idled perfectly for miles on the water, however it was covering the plugs with black oil / soot. I converted this engine to premix while I had everything apart and ran it a 50:1.

After the engine warmed up, I gave it throttle and as soon as the butterfly valves on the manifold opened, it would bog and die unless I closed the throttle back to zero.

I replaced the trigger as the wires were frayed and made sure the stator was in working order. As mentioned earlier, it starts very fast and will idle nicely (even though the tach is running about 3-4k rpms too high??) The voltage regulators are showing 14.2 at fast idle.

I then tested the TPS after unhooking the working port sensor and I was able to get the voltage to .15-.20 volts. WOT voltage on the sensor was only 3.3v.

Just for kicks I unplugged the throttle sensor and the boat would run very rich at idle but it was able to accelerate ( I didn't open it up very much)..The boat now runs with the throttle plates partially open. The TPS disconnected make a immediate difference in allowing the boat to take SOME throttle (smoky but no surging). Also, I cleaned all filters and have 34psi when running. Port side cylinders seem to have a little less soot on them when reading plugs.

I'm going to purchase the Candoo Mercury Tool to help solve a lot of common issues that these boats have. I hope to offer insight to the forum as I learn more about how to use the tool.

While I wait for the tool, does anyone have any ideas on why disconnecting the TPS sensor allowed the boat to accelerate ( Tach is running very high for some reason so I don't know how many RPMS I was running at). I have attached some Pics of this boat transformation.. I previously had a 2003 Challenger X with the 250 opti. It ran great but had a weak hull (bad hull)... This boat is solid but needs some tweaking on the engine..


Thanks again!
Joe

 

[Tim75]

Wow!!! That is beautiful! I wish someone would do that to my Challenger. That is REALLY blue! Looks great!

Engine: Tps adjusts air/fuel from idle to about 3/4 throttle. If you are unable to adjust to proper values, tps may be dead. Have you tested it? Many thread here about testing.

What I suspect more than tps is the injectors. I have the same boat & engine. Face it. The injectors are 20 years old and have had there share of neglect. Take them out and have them serviced. Best thing I ever did for better performance and less fuel consumption. You may have leakers, or poor spray patterns. Injector cleaner liquids are worthless and potentially damaging. Yes, the intake manifold has to come off again.

Tach: important diagnostic tool. There are 2 voltage regulators on this engine. Tach signal is from the gray wire on a reg. Swap it to the other reg. Double check the ground at the gauge.

Comp.: 121 is a little low, but should run. Was it checked at WOT with all plugs out?

 

[svtjoe98]

Wow!!! That is beautiful! I wish someone would do that to my Challenger. That is REALLY blue! Looks great!

Engine: Tps adjusts air/fuel from idle to about 3/4 throttle. If you are unable to adjust to proper values, tps may be dead. Have you tested it? Many thread here about testing.

What I suspect more than tps is the injectors. I have the same boat & engine. Face it. The injectors are 20 years old and have had there share of neglect. Take them out and have them serviced. Best thing I ever did for better performance and less fuel consumption. You may have leakers, or poor spray patterns. Injector cleaner liquids are worthless and potentially damaging. Yes, the intake manifold has to come off again.

Tach: important diagnostic tool. There are 2 voltage regulators on this engine. Tach signal is from the gray wire on a reg. Swap it to the other reg. Double check the ground at the gauge.

Comp.: 121 is a little low, but should run. Was it checked at WOT with all plugs out?

Thanks! It was a bunch of work to clean it up cosmetically. It has a cool look.

Yep 121 is what it read with the throttle plates open. This was before I had it running..so it sat for a few years.

The previous owner said he had the injectors cleaned just before I bought it (he turned out to be a pretty honest guy).

My Candoo scan tool just arrived. I should be able to test the TPS with that tool. In addition, I have tried switching the tach to the other voltage regulator. It still shows very very high. Have you timed one of these engines yet? I believe I need to adjust the timing too as I have played with the throttle arm and spark adjust screws...

Thanks,
Joe

 

[svtjoe98]

I tested the tps today with a analog meter (ohms) It was very smooth throughout the entire range. I believe it’s still low on voltage though. I’ll hook it up to the Candoo tomorrow and see what type of info I get from it.

Happy New Year!

Joe

 

[Tim75]

I tested the tps today with a analog meter (ohms) It was very smooth throughout the entire range. I believe it’s still low on voltage though. I’ll hook it up to the Candoo tomorrow and see what type of info I get from it.

Happy New Year!

Joe

Did you disconnect temp sensor, port side head when testing tps?

 

[svtjoe98]

Did you disconnect temp sensor, port side head when testing tps?

Yep I sure did before I used the diagnostic system. The boat fires up and runs right away without TPS with a lot of 2 stroke premix smoke.

I set it to .25 volts at idle and it will start but then die. The only way to set this to .25v at idle was to install it outside of where the holes line up. When WOT I get nearly 5v. The boat is idling high (but steady) with the throttle plates completely closed and the idles screws turned all the way in.

Here’s the info from Candoo:

 

[Tim75]

When you checked the tps by resistance (ohms), did you check both sides? That is, center pin and left pin, then center pin and right pin. They work in opposite directions. Both sides need to work smoothly, no jumping.

Looking at the wire diagram, it shows that the voltage for tps comes from the ecu. Have you checked the round connector, starboard side, clipped to the engine? Looking for bright shiny pins and sockets. There are lots of wires there, Be careful. Frequently, the plastic nut that holds both halves of that connector together will break. You can use zip-ties to hold the whole thing together if you need to. Also check all the ground wires. There is one at the top of the ecu to the intake manifold. All these need to be clean. A ground issue could also cause your tach problems. It does not take much salt water use to cause electrical problems.

On your Candoo, it show the tps as INACTIVE. Further down it shows 4.95 volts. Not familiar with that tool. It seems that tps is either ACTIVE with a voltage or INACTIVE with no voltage. A bit of confusion here.

Still concerned about injectors. Were they actually removed and tested/adjusted on a flow bench?

 

[Tim75]

When you put the intake manifold back on, did you have to re-install the fuel rail?

If you did, it is VERY easy to cut one or more of the o-rings on the top of the injector. This would definitely lead to a rich, smokey, and leaky condition.

Those o-rings are hard to find. Odd size. The only place I found them was.............. the injector service center.

 

[svtjoe98]

When you put the intake manifold back on, did you have to re-install the fuel rail?

If you did, it is VERY easy to cut one or more of the o-rings on the top of the injector. This would definitely lead to a rich, smokey, and leaky condition.

Those o-rings are hard to find. Odd size. The only place I found them was.............. the injector service center.

I just wanted to update you on my 240 issue. I pulled off the pulse pump and found it was all gel’d up. I rebuilt it and then cranked it up. It was better but it still didn’t want to stay running. I then looked at spin on fuel filter and figured I would look at the line running to it. It was completely blocked.. I think the hose is falling apart along with ethanol debris. I’m replacing all fuel lines today and will give it another go. The vapor tank drained with clean fuel in it with no water. I’m certain I have a fuel flow issue.

Next fix will be to pull injectors and send them out to be cleaned. I didn’t remove them when I assembled everything so I’d assume the o rings are still there. That same debris was also completely clogging the line that runs to the inlet of the spin on filter!

 

[Tim75]

I have actually seen worse that that.

Be careful of those little flapper valves.

Your fuel lines-- Any chance they were grey? Some boats left the factory with grey hose that was quickly found to be junk. Ethanol attacked the hose and made it delaminate and collapse. Turned brittle to the point it could break.

 

[svtjoe98]

I have actually seen worse that that.

Be careful of those little flapper valves.

Your fuel lines-- Any chance they were grey? Some boats left the factory with grey hose that was quickly found to be junk. Ethanol attacked the hose and made it delaminate and collapse. Turned brittle to the point it could break.

Making progress! The hoses are a lighter shade of black but I was able to bypass spin on filter and bypass primer pump. I hooked a new line w/ primer bulb right from the tank directly to the inlet of the newly rebuild pulse pump.

The boat started right away with TPS hooked up. It then died. I started messing with the Vapor Separator (I installed new electric pump in VST a while back). In hind sight, I should go through it again and use the correct gasket (I used gasket maker where the top and bottom meet). During this time I switched to premix and removed most of the oil injection.

I noticed I was able to get the boat running strong when I removed the oil line from the very bottom of the VST and put my finger over it. When converting to premix, what do I do with the oil injection port on the bottom of the VST? With the hose removed (no oil flowing to
It) it drips fuel. With the engine running, I removed my finger from covering this hole and the engine eventually dies. With my finger over hole it revved up and sounded great.

I have the VST just bolted on with one bolt as I’ve been chasing this fuel issue..

I noticed sediment in bottom of clear glass when I drained VST. I assume that little filter is probably blocked now.

 

[Tim75]

Making progress! The hoses are a lighter shade of black but I was able to bypass spin on filter and bypass primer pump. I hooked a new line w/ primer bulb right from the tank directly to the inlet of the newly rebuild pulse pump.

The boat started right away with TPS hooked up. It then died. I started messing with the Vapor Separator (I installed new electric pump in VST a while back). In hind sight, I should go through it again and use the correct gasket (I used gasket maker where the top and bottom meet). During this time I switched to premix and removed most of the oil injection.

I noticed I was able to get the boat running strong when I removed the oil line from the very bottom of the VST and put my finger over it. When converting to premix, what do I do with the oil injection port on the bottom of the VST? With the hose removed (no oil flowing to
It) it drips fuel. With the engine running, I removed my finger from covering this hole and the engine eventually dies. With my finger over hole it revved up and sounded great.

I have the VST just bolted on with one bolt as I’ve been chasing this fuel issue..

I noticed sediment in bottom of clear glass when I drained VST. I assume that little filter is probably blocked now.



View attachment 46129

Making progress! The hoses are a lighter shade of black but I was able to bypass spin on filter and bypass primer pump. I hooked a new line w/ primer bulb right from the tank directly to the inlet of the newly rebuild pulse pump.

The boat started right away with TPS hooked up. It then died. I started messing with the Vapor Separator (I installed new electric pump in VST a while back). In hind sight, I should go through it again and use the correct gasket (I used gasket maker where the top and bottom meet). During this time I switched to premix and removed most of the oil injection.

I noticed I was able to get the boat running strong when I removed the oil line from the very bottom of the VST and put my finger over it. When converting to premix, what do I do with the oil injection port on the bottom of the VST? With the hose removed (no oil flowing to
It) it drips fuel. With the engine running, I removed my finger from covering this hole and the engine eventually dies. With my finger over hole it revved up and sounded great.

I have the VST just bolted on with one bolt as I’ve been chasing this fuel issue..

I noticed sediment in bottom of clear glass when I drained VST. I assume that little filter is probably blocked now.



View attachment 46129

If you are running pre-mix-
The fitting on the bottom of the vst appears to thread in (Merc manual). Can you unscrew that and replace it with a pipe plug? That fitting is probably installed with red locktite, Pretty tight. Use the perfect size wrench. Match the threads to each other to be sure they are the same. In the vst, the tank is only pressurized to about 5psi. The higher pressure is inside the pump body. That pump can go to about 85 psi. (My regulator failed and that is what my injectors saw. Yeh, it was a little smokey.)

TPS- any chance it is installed backward? No too hard for you to check at this point. Don't lose the little sleeve that helps align the shaft.

Ground wires- I believe there are at least 3. One at the ECU, one on the plate holding the ignition coils, and the neg. battery cable. All need clean, tight connections.

 

[svtjoe98]

I’ll see what size that metric plug is and get it sealed. I’ll take apart the VST tomorrow and install new gaskets and clean it all up with air tight fittings. I know for a fact I don’t have a ground connected to the ECU. From my service manual I only see a ground going from one of the bolts on the injector plate cover to the ecu mounting bolt on top. I haven’t made up a new wire for that yet. I didn’t see a ground coming from the ecu chassis or anything. Is there one? Or is the top mounting bracket the actual ground?

The fuel that came out of the VST was so dirty looking. I have nearly a full tank of fresh premixed fuel and it was cloudy as heck when coming out of the VST. I’ll replace all hoses tomorrow along with checking the TPS again. I’ll keep you posted. Thanks so much for your help!

 

[Tim75]

Does your gas have ethanol in it? If you have an empty tank (no gas) but has some water in it, when you add new gas with ethanol, it will be cloudy as the ethanol absorbs water into the mix.

There are some threads here about gas/ethanol/water and none of them are good news.

 

[svtjoe98]

It may have had 4 gallons of old
Gas in it. I’ve since put 30 gallons of fresh and looked for separation. No water so far on bottom of clear jug. I saw more black flakes than anything. I just picked up the VST gasket from local Merc Indy. Crazy to think that mess would make it all the way to the VST..

Btw. I had some gas out of spin on filter and VST drain put into a clear jar. That jar sat outside for 2 days and it was nearly evaporated. No doubt bad gas. Can you let me know who bench tested and calibrated your injectors?

 

[Tim75]

I used HAVOC SPEED in West Palm. Great service. I sent them in Weds. afternoon, got them back Friday afternoon. With a preservice and post service report. $20 each plus shipping. Including new o-rings and strainers (in the end of each inj.). Best money I have spent for any kind of maintainence. havocspeed.com

Every big city should have a similar shop.

There is another strainer on the bottom of fuel pickup tube.

 

[svtjoe98]

Perfect. I live in Lighthouse point. If my rebuild of the VST tank doesn’t work I’ll drive the injectors up!! Thanks!!

 

[svtjoe98]

I used HAVOC SPEED in West Palm. Great service. I sent them in Weds. afternoon, got them back Friday afternoon. With a preservice and post service report. $20 each plus shipping. Including new o-rings and strainers (in the end of each inj.). Best money I have spent for any kind of maintainence. havocspeed.com

Every big city should have a similar shop.

There is another strainer on the bottom of fuel pickup tube.

I checked that pick up and it was perfect. The hoses have been falling apart I think.

 

[svtjoe98]

Well..I rebuilt and cleaned out the vapor separator. Cleaned screens. Regulator screen clean. Sealed it up with OEM gasket. Started perfect and then wanted to die. Replaced all fuel lines with new ones. No leaks. Boat will start and die within 5 seconds now. I pulled off tps while running to increase voltage and it would run and run.

Last thing to check... injectors? I’m at a loss with this one. It will rev up better than it did after I cleaned vst. VST was dirty dirty. I’ll get it to rev to 3k or so with tps disconnected. I’ll pull injectors and keep you posted. I really believe this is a fuel issue and not a spark issue.

 

[Tim75]

Well..I rebuilt and cleaned out the vapor separator. Cleaned screens. Regulator screen clean. Sealed it up with OEM gasket. Started perfect and then wanted to die. Replaced all fuel lines with new ones. No leaks. Boat will start and die within 5 seconds now. I pulled off tps while running to increase voltage and it would run and run.

Last thing to check... injectors? I’m at a loss with this one. It will rev up better than it did after I cleaned vst. VST was dirty dirty. I’ll get it to rev to 3k or so with tps disconnected. I’ll pull injectors and keep you posted. I really believe this is a fuel issue and not a spark issue.

Have you checked the ignition trigger coil? 6 wire connector aft of flywheel. Can cause myriad problems.

 

[svtjoe98]

Well.. I was able to solve some of the issues. I had a bad connection on the bullet connector. It caused a air temp fault and maybe a trigger fault. The trigger is new.

I secured those bullet connections and started the engine. It ran and didn’t die, but it was smoky. No faults on the scanner.

I tested the fuel pressure at the valve and had 35psi with key on. Maybe 33-35 while boat was running. As soon as the high pressure pump stopped running, pressure started dropping. It dropped to around 20 psi.

Are we thinking regulator? The fuel pump is a new aftermarket unit. The pulse pump was just rebuilt. There are no leaks in the line. I Eliminated the check valve in the line from the tank to simplify trouble shooting.

Thanks!

I’m told I can try clear tubing from the pulse pump to the VST to ensure I don’t have any air entering the fuel line.

 

[svtjoe98]

I just found a post that mentioned the fuel rail can leak due to bad o rings. This may be the reason why I have excessive smoke after it dies. Fuel coming out the exhaust..

It could be puddling up and obviously the fuel rail is not holding pressure. I’ll take the induction manifold off tonight and see what the deal is.

Thanks again for all your help!

 

[Tim75]

About your injectors-
Just in case you cut an o-ring at reassembly, SAVE THE OLD ONES! This also gives a chance to examine the old ones for damage. On the top of each inj. is the last chance for clean gas. Small green strainer. Check those for dirt. Havoc will replace them anyway. Use toothpicks to remove o-rings. Metal tools can scratch the o-ring groove and make a leak. Vaseline on the new o-rings at assembly.

Clear hose for gas is only for testing. There is no clear hose rated for gas.

Regulator- about $300 from Merc. Rock Auto has similar looking units, but no spec on the pressure set. My reg. seems to be stuck. My system pressure was 85psi. I found a high performance reg. on ebay for about $50 and plumbed that in. Now running at 36psi. Runs great!

Have you checked all the small black hoses that run all over the block? These pull pooled gas into the air flow to be burned. Missing/broken hoses could cause vacuum leaks and stalling. Could also cause a lean condition and meltdown. I used weedeater fuel line to replace that old black hose. Be careful of those small brass hose nipples. They are easy to break.

 

[nenikol23]

svtjoe98 Were you able to resolve this issue? Was it the injectors? Or something else?
I have similar troubles and looking for info.