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View Full Version : 95 maristar vrs wont start hot


gr82bgreen
06-29-2011, 04:06 PM
Having trouble with my 200 vrs 350 tbi 275 hp. It starts and runs really well cold. IT runs perfect untill after about a half hour or more of skiing. It will be running fine, I shut it off and it will not restart. I remove the flame arester. there is fuel coming out of the throttle body. I have a spark when I pull the coil wire. there is loads of smoke coming from the exhaust and an awful smell. I have replaced the ignition module and coil. plugs, cap, rotor and wires are fairly new. If I let it sit and cool for 5 - 10 minutes it starts right up and runs perfect untillI shut it off again. Any Ideas. Thanks.

1redTA
06-29-2011, 05:23 PM
vapor lock? inlet air temp sensor?

gr82bgreen
06-29-2011, 06:19 PM
vapor lock? inlet air temp sensor?

everything I read says efi does not vapour lock. Does this engine have a inlet temp sensor?

JimN
06-29-2011, 06:42 PM
everything I read says efi does not vapour lock. Does this engine have a inlet temp sensor?

No IAT on early marine applications.

JimN
06-29-2011, 06:44 PM
Having trouble with my 200 vrs 350 tbi 275 hp. It starts and runs really well cold. IT runs perfect untill after about a half hour or more of skiing. It will be running fine, I shut it off and it will not restart. I remove the flame arester. there is fuel coming out of the throttle body. I have a spark when I pull the coil wire. there is loads of smoke coming from the exhaust and an awful smell. I have replaced the ignition module and coil. plugs, cap, rotor and wires are fairly new. If I let it sit and cool for 5 - 10 minutes it starts right up and runs perfect untillI shut it off again. Any Ideas. Thanks.

Look here for how to retrieve codes- you will need a paper clip. Open the throttle a little next time and see if it's better. If it is, I would say the coolant temperature sensor or IAC is have a problem.

Don't replace parts unless you know they're actually bad.

gr82bgreen
06-29-2011, 06:48 PM
Look here for how to retrieve codes- you will need a paper clip. Open the throttle a little next time and see if it's better. If it is, I would say the coolant temperature sensor or IAC is have a problem.

Don't replace parts unless you know they're actually bad.

I removed throttle linkage and it will not start at any position, not even WOT.

JimN
06-29-2011, 07:13 PM
I removed throttle linkage and it will not start at any position, not even WOT.

Do you see fuel coming from both injectors, or just one?

Check the codes first, then look at the safety switch and neutral safety switch. Also, do a wiggle test on the ground leads at the rear of the engine with the key ON. If you hear the fuel pump buzz, you found the area where the problem lies.

gr82bgreen
06-29-2011, 07:17 PM
Do you see fuel coming from both injectors, or just one?

Check the codes first, then look at the safety switch and neutral safety switch. Also, do a wiggle test on the ground leads at the rear of the engine with the key ON. If you hear the fuel pump buzz, you found the area where the problem lies.

Fuel at both injectors. Would I have spark and fuel if the safety switches were at fault. I will check and clean all grounds. thanks.

ahhudgins
06-29-2011, 08:24 PM
I had the exact same problem with my 95 200VRS after I changed the thermostat from the 143 degree to a 160. With the 143 degree thermostat, it seemed to run a little rich because I had a faint smell of gas out of the exhaust. I put in a 160 degree t-stat and the smell wasn't so obvious but I had the same problem that you did.

I noticed the problem when I was teaching some kids to ski. I would shut the boat off to give some instructions and it would crank but not fire up. After spending a few minutes checking the engine over it would finally start back up. After this happened a few times I decided to put the original 143 t-stat back in and the problem went away. I have swapped the stats a few times and it's definitely related to the engine temperature. I've since left the original stat in the engine and I have no problems. I was considering buying some diagnostic software to see what the ECM is seeing for the engine temperature. The temperature gauge runs off of another sending unit and it is reading correctly.

I installed one of the code readers and it shows no codes. I'm thinking the temperature sending unit or maybe the ignition coil getting too hot? I wish I could be more help, but I've kind of let the issue go since my engine runs with the 143 degree stat. My 95 manual does call for that temperature.

ahhudgins
06-29-2011, 08:33 PM
Forgot to mention that I also have fuel at the injectors. The neutral switch at the transmission keeps it from cranking at all. The lanyard kill switch will allow it to crank but not start (never checked if I had fuel with the lanyard pulled). See what your temperature gauge is reading before you shut it off too....make sure you don't have a cooling issue.

If no one has a solution, I'll mess around with mine this weekend by putting the 160 degree t-stat back in.

JimN
06-29-2011, 10:35 PM
Fuel at both injectors. Would I have spark and fuel if the safety switches were at fault. I will check and clean all grounds. thanks.

For whatever reason, I wrote that the neutral safety switch would keep it from starting but it will actually keep it from cranking. If you see fuel, you obviously have RPM info getting to the ECM, or it wouldn't allow the fuel pump to turn on.

If the sees overheat, the ECM will cut off fuel to alternate banks of cylinders and in the case of TBI, it will toggle between the two injectors.

Check for spark- you may find that you have it on the coil wire but not to the plugs, which could be caused by a loose/sagging harness to the distributor or coil.

gr82bgreen
06-30-2011, 12:55 AM
I had the exact same problem with my 95 200VRS after I changed the thermostat from the 143 degree to a 160. With the 143 degree thermostat, it seemed to run a little rich because I had a faint smell of gas out of the exhaust. I put in a 160 degree t-stat and the smell wasn't so obvious but I had the same problem that you did.

I noticed the problem when I was teaching some kids to ski. I would shut the boat off to give some instructions and it would crank but not fire up. After spending a few minutes checking the engine over it would finally start back up. After this happened a few times I decided to put the original 143 t-stat back in and the problem went away. I have swapped the stats a few times and it's definitely related to the engine temperature. I've since left the original stat in the engine and I have no problems. I was considering buying some diagnostic software to see what the ECM is seeing for the engine temperature. The temperature gauge runs off of another sending unit and it is reading correctly.

I installed one of the code readers and it shows no codes. I'm thinking the temperature sending unit or maybe the ignition coil getting too hot? I wish I could be more help, but I've kind of let the issue go since my engine runs with the 143 degree stat. My 95 manual does call for that temperature.

I don't seem to have a cooling issue. Impeller was new last year. I just pulled my thermostat and it is a 160. I noticed driving that my engine runs about 180 and likely climbs higher when shut off. I am going to try a 143 and am betting that fixes my problem as it is obviously heat related. FYI, I installed a new msd high output coil and it made no difference. IT always starts and runs perfect untill it reaches max opperating temp. Is the t/stat marine specific?

ahhudgins
06-30-2011, 02:10 PM
If you have a 160 degree t-stat and your gauge is showing 180 degrees, I would double check that impeller and check the screen for junk. I'm pretty sure skidim.com sells the 143 degree stat, but I'm not sure if it's marine specific.

If you can't get a 143 degree t-stat before your next lake trip, you could just take the 160 out and see if the starting issue goes away. This will make it run a little rich too.

I don't know if you remember, but I contacted you about the weird issue of my RPMs being limited to around 2500 in neutral and you and another 200VRS owner said yours does the same thing. Seems to be programmed into the ECM but my MC dealer just scratched his head! :rolleyes:

gr82bgreen
06-30-2011, 08:31 PM
The rpm issue may be due to limited throttle opening in neutral. Mine is far from WOT in neutral. I got a 140 t/stat today. My impeller is new and the old one was fine when I changed it.

ahhudgins
06-30-2011, 08:36 PM
The rpm issue may be due to limited throttle opening in neutral. Mine is far from WOT in neutral. I got a 140 t/stat today. My impeller is new and the old one was fine when I changed it.

Let us know how the new stat works. I know you say that the impeller is "new" but I would still check it. I never assume something is still perfect once it's been installed (crap happens). I'm taking a well deserved 5 day weekend for the 4th so I'm going to mess around with my thermostat. Good luck.

gr82bgreen
07-11-2011, 01:40 PM
Let us know how the new stat works. I know you say that the impeller is "new" but I would still check it. I never assume something is still perfect once it's been installed (crap happens). I'm taking a well deserved 5 day weekend for the 4th so I'm going to mess around with my thermostat. Good luck.

Ran it all day yesterday without any issues. Engine ran at 150 degrees. It would creep up to 180 or so when shut off before trying to start, but would start no problem. It seems to me that before it would be over 190 when it would not fire. Hopefully this was my issue. I may replace the ecu sending unit just to be safe.

JimN
07-11-2011, 03:10 PM
Ran it all day yesterday without any issues. Engine ran at 150 degrees. It would creep up to 180 or so when shut off before trying to start, but would start no problem. It seems to me that before it would be over 190 when it would not fire. Hopefully this was my issue. I may replace the ecu sending unit just to be safe.

ECU sending unit? You mean the coolant temperature sender, right? If you don't have black smoke on hot startup and it doesn't go into RPM reduction when it's cold or at normal operating temperature, the sender is fine.

If you want to service your own boat, buy a good manual and the proper test equipment instead of throwing parts at it, and money out the window..

gr82bgreen
07-11-2011, 03:51 PM
ECU sending unit? You mean the coolant temperature sender, right? If you don't have black smoke on hot startup and it doesn't go into RPM reduction when it's cold or at normal operating temperature, the sender is fine.

If you want to service your own boat, buy a good manual and the proper test equipment instead of throwing parts at it, and money out the window..

YEs I meant the temp sending unit that goes to the computer and not the gauge. So far I have thrown $58.00 dollars at it in the coil and thermostat. The coil was 17 years old and now upgraded to a performance coil. It had the wrong t/stat, so it needed to be changed. The temp sending unit is what maybe $25.00. 1 hr labour at a shop is over $100.00 plus parts and maybe a week wait. I get where your coming from as I am a ford auto tech. But my lack of familiarity with a marine GM engine is why I came to this forum. I apppreciate your input as well as others and am just looking at how to fix my concern.

JimN
07-11-2011, 04:18 PM
YEs I meant the temp sending unit that goes to the computer and not the gauge. So far I have thrown $58.00 dollars at it in the coil and thermostat. The coil was 17 years old and now upgraded to a performance coil. It had the wrong t/stat, so it needed to be changed. The temp sending unit is what maybe $25.00. 1 hr labour at a shop is over $100.00 plus parts and maybe a week wait. I get where your coming from as I am a ford auto tech. But my lack of familiarity with a marine GM engine is why I came to this forum. I apppreciate your input as well as others and am just looking at how to fix my concern.

If you work for a dealer or auto shop, ask the other guys about GM diagnostics- car/truck/boat- it's all the same. If you had hot start issues, it may have been heat soak that caused it. If it happens again, open the motor cover and turn the blower on- if it cools and starts, it's heat soak. Another way to test- if it won't start when hot, crack the throttle a bit- if it starts, it could be the ECT or the IAC isn't parking correctly. You can see the IAC pintle when the flame arrestor is off, it should open and settle in to set idle speed when you first start the engine and when you open the throttle, the pintle should open (it "follows" the throttle and this is called "IAC follower function". When you shut it down, the pintle should close, pause and then open a bit. When you start it again, you should see the pintle open and settle in at idle every time.

Any OBDI service manual will work for these- you just have to ignore the IAT (Intake Air Temperature), Catalytic, O2 sensor, oil pressure and MAF info because it doesn't apply.

The basic breakdown for these is as follows:

The TPS should show 2 or less at idle. If it shows more, the ECM changes so the MAP sensor's input has priority- the TPS is mainly used when the throttle position has a delta of 20 or more. If the delta is negative, it goes into deceleration enleanment (shuts the injectors down to reduce the RPM faster) and if it's a positive delta, it goes into acceleration enrichment. If the TPS fails, the ECM defaults to 12% throttle position and the engine's throttle response will be sluggish. It should also lose some top end.

If the MAP sensor is bad, it may have problems starting, maintaining smooth acceleration and it will be sluggish. It also may hunt for correct idle speed.

If the ECT is bad, it will do what I mentioned before. If the sensors test OK, you'll want to do continuity tests to the ECM terminals. The standard shop manuals won't help you with this but if you have the TBI or LT-1, I have the manuals and can post the terminals that correspond to the sensor wires.

The TPS, ECT and MAP sensor can be tested with a multi-meter and a manual will show the proper values for voltage and resistance.

A Haynes manual will be fine for this- I haven't been too impressed by Chilton's. If you have access to Mitchell Manuals, that's even better.

gr82bgreen
07-11-2011, 04:39 PM
If you work for a dealer or auto shop, ask the other guys about GM diagnostics- car/truck/boat- it's all the same. If you had hot start issues, it may have been heat soak that caused it. If it happens again, open the motor cover and turn the blower on- if it cools and starts, it's heat soak. Another way to test- if it won't start when hot, crack the throttle a bit- if it starts, it could be the ECT or the IAC isn't parking correctly. You can see the IAC pintle when the flame arrestor is off, it should open and settle in to set idle speed when you first start the engine and when you open the throttle, the pintle should open (it "follows" the throttle and this is called "IAC follower function". When you shut it down, the pintle should close, pause and then open a bit. When you start it again, you should see the pintle open and settle in at idle every time.

Any OBDI service manual will work for these- you just have to ignore the IAT (Intake Air Temperature), Catalytic, O2 sensor, oil pressure and MAF info because it doesn't apply.

The basic breakdown for these is as follows:

The TPS should show 2 or less at idle. If it shows more, the ECM changes so the MAP sensor's input has priority- the TPS is mainly used when the throttle position has a delta of 20 or more. If the delta is negative, it goes into deceleration enleanment (shuts the injectors down to reduce the RPM faster) and if it's a positive delta, it goes into acceleration enrichment. If the TPS fails, the ECM defaults to 12% throttle position and the engine's throttle response will be sluggish. It should also lose some top end.

If the MAP sensor is bad, it may have problems starting, maintaining smooth acceleration and it will be sluggish. It also may hunt for correct idle speed.

If the ECT is bad, it will do what I mentioned before. If the sensors test OK, you'll want to do continuity tests to the ECM terminals. The standard shop manuals won't help you with this but if you have the TBI or LT-1, I have the manuals and can post the terminals that correspond to the sensor wires.

The TPS, ECT and MAP sensor can be tested with a multi-meter and a manual will show the proper values for voltage and resistance.

A Haynes manual will be fine for this- I haven't been too impressed by Chilton's. If you have access to Mitchell Manuals, that's even better.

Thanks, all great info. I will persure if issue returns.