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  #21  
Old 09-29-2014, 01:46 PM
SenselessSteve SenselessSteve is offline
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Boat: 1995 Mastercraft Pro Star 190 LT1
Location: Northern Ireland
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I tested the voltage on the TPS (engine off). It ranges from about 0.7 to 4.2 at WOT.

I removed the MAP sensor to check the rubber gasket where the MAP vacuum pipe inserts at top of the intake manifold was was making a good seal - all appears fine.

I noticed that the plate with 6 screws on top of the throttle body appears to have a very distorted gasket underneath. I opened it up to reveal a very distorted rubber gasket that seems to be heat damaged. I'll need to replace this anyway as it's a mess. Have you ever had this cause trouble with mixture?

Thanks again
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  #22  
Old 09-29-2014, 03:46 PM
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JimN JimN is offline
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Originally Posted by SenselessSteve View Post
I tested the voltage on the TPS (engine off). It ranges from about 0.7 to 4.2 at WOT.

I removed the MAP sensor to check the rubber gasket where the MAP vacuum pipe inserts at top of the intake manifold was was making a good seal - all appears fine.

I noticed that the plate with 6 screws on top of the throttle body appears to have a very distorted gasket underneath. I opened it up to reveal a very distorted rubber gasket that seems to be heat damaged. I'll need to replace this anyway as it's a mess. Have you ever had this cause trouble with mixture?

Thanks again
I never needed to remove the cover, so, no.

.7VDC-4.2VDC is fine but the code still bothers me. Disconnect the battery for a half hour, reconnect and check for codes again. If you see none, start it and see if it's any better.

Did you disconnect/reconnect any of the sensors while the key was on or the engine running? That can cause a code situation.
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  #23  
Old 09-29-2014, 04:27 PM
SenselessSteve SenselessSteve is offline
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Boat: 1995 Mastercraft Pro Star 190 LT1
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Hi Jim. I disconnected the battery for an hour while I had dinner. Came back and reconnected (all sensors in place).

I started the boat and let it idle while I measured the voltages.

TPS at idle was around 0.72 and increased steadily when I applied throttle.

Checked MAP. Steady 5V at the grey control but when I measured the green return it was bouncing around 1.6 (at idle). Applying throttle made the Voltage decrease (to around 0.9V at 3500rpm)

Still strong smell of gas and I could actually see it slick in the water gathering on the ground below the flaps.

Tried the paperclip exercise and again I had codes 14 and 21.

Also felt that the riser on the port side was a lot cooler in comparison to other.
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  #24  
Old 09-29-2014, 05:54 PM
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JimN JimN is offline
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Quote:
Originally Posted by SenselessSteve View Post
Hi Jim. I disconnected the battery for an hour while I had dinner. Came back and reconnected (all sensors in place).

I started the boat and let it idle while I measured the voltages.

TPS at idle was around 0.72 and increased steadily when I applied throttle.

Checked MAP. Steady 5V at the grey control but when I measured the green return it was bouncing around 1.6 (at idle). Applying throttle made the Voltage decrease (to around 0.9V at 3500rpm)

Still strong smell of gas and I could actually see it slick in the water gathering on the ground below the flaps.

Tried the paperclip exercise and again I had codes 14 and 21.

Also felt that the riser on the port side was a lot cooler in comparison to other.
If one riser was warmer, it's fairly normal at idle, but at higher RPM, it indicates a problem. If it was on the trailer, don't run it at high RPM- the water supply usually can't keep up with the raw water pump.

What is the resistance of the ECT? (the one with one yellow and one black wire). If it's 20C/68F, the resistance should be about 3520 Ohms. If it's significantly lower, it's bad. If it's higher, it would indicate low temperature, which would cause a 15 code.
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  #25  
Old 09-29-2014, 06:23 PM
SenselessSteve SenselessSteve is offline
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I went to check the resistance (boat still Luke warm from earlier testing) and it was reading 1240
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  #26  
Old 09-29-2014, 06:35 PM
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JimN JimN is offline
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I went to check the resistance (boat still Luke warm from earlier testing) and it was reading 1240
Here's a list of resistance values-

http://www.hptuners.com/forum/showth...istance-values

Measure it again after it cools completely.

Next time, feel the manifold next to the ECT- if it's noticeably hot, measure the resistance and compare it to the table in the link. You'll need to scroll down a bit, but copy it to a Word (or other) document for future reference.
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  #27  
Old 09-30-2014, 08:43 AM
SenselessSteve SenselessSteve is offline
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Boat: 1995 Mastercraft Pro Star 190 LT1
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Thanks Jim. I measured the resistance as the engine ran from cold at idle.

It started off at around 3600 Ohms and fell steadily to around 1000 Ohms before I shut it off.

I ran for codes and again got 14 and 21.

Very strange indeed. I've also head the fuel pump starting to squeal quite a bit as it pressurises so I'm going to check fuel pressure again once I get my pressure tester back off a local borrower (damn I hate lending out tools)

Thanks again. The show goes on
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