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testing the crank trigger and TPS

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JL242

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I don't have the test harness. I do have a good electrical ohms meter. Could someone please ELI5 and walk me through each procedure of testing the crank trigger and TPS. I have been having issues with warm re-restarts, excessive smoke and poor fuel consumption. I have a 2001 Challenger 1800 with a 240 EFI. I have replaced the port side temperature sender. I would also like to know the procedure for testing coil packs too. I have an electronic copy of the shop manual. I had a Mercury mechanic tell me that he tested my TPS and its fine. However he's the same guy that destroyed my VST gasket and caused VST to leak, so he's done working on my boat. Thanks for any assistance.
 
1st, does your warning system operate correctly as described? The reason is, if warning system isn't functioning, there may be a fault code and you'd never know some problem exists.

"Controls Power-Up Sequence – 1/2 second after ignition key is turned to
“ON”, and power is applied to ECM, warning lamps will illuminate for 1/2
second and horn will beep for 1/2 second."
 
If your crank sensor was bad it would not fire (recently been there). It should read ~ 300 Ω. Mine was 900KΩ or so. Easy to verify with a meter, but unlikely to cause your issue IMHO.
 
1st, does your warning system operate correctly as described? The reason is, if warning system isn't functioning, there may be a fault code and you'd never know some problem exists.

"Controls Power-Up Sequence – 1/2 second after ignition key is turned to
“ON”, and power is applied to ECM, warning lamps will illuminate for 1/2
second and horn will beep for 1/2 second."

warning lamps illuminate and I hear an electronic beep, no horn though.
 
I don't have the test harness. I do have a good electrical ohms meter. Could someone please ELI5 and walk me through each procedure of testing the crank trigger and TPS. I have been having issues with warm re-restarts, excessive smoke and poor fuel consumption. I have a 2001 Challenger 1800 with a 240 EFI. I have replaced the port side temperature sender. I would also like to know the procedure for testing coil packs too. I have an electronic copy of the shop manual. I had a Mercury mechanic tell me that he tested my TPS and its fine. However he's the same guy that destroyed my VST gasket and caused VST to leak, so he's done working on my boat. Thanks for any assistance.

re: tps
I have the same engine in 20 footer.
Let's separate TEST from ADJUST.
For testing: disconnect the tps plug/harness (3 pin connector.)
Set meter to OHMS, 20K range. (might need to change range.) Actually an old analog (needle) meter works best, but digital will work. Use tiny jumper wires (the kind Radio Shack used to sell). Connect one lead to center pin of tps connector. Connect 2nd lead to either outer pin. Advance throttle from idle to WOT. Meter should change SMOOTHLY. Swap 2nd lead to other outer pin. Advance throttle from idle to WOT. Again, meter should change SMOOTHLY. Any jumping or erratic reading is a fail. TPS is dead. If tps is erratic, the ECU will default to safe mode, which is full rich on the fuel.

If tps is good, then adjust.
There is a test harness available that makes the procedure almost painless. I paid less than $20 for mine.
Connect tps back to harness. Disconnect head temp sensor on port side. Key on, engine off. Set meter to 20V DC. You need sewing pins to pierce the insulation on center and one outer wire. Use your little jumper wires. How do you know which outer wire? Pick one. You have the right one when voltage INCREASES from idle to WOT. Voltage should be about 0.3 at idle to about 7.5 at WOT. This is where you will need to loosen screws on tps in order to rotate it SLIGHTLY. Again, meter reading should not be erratic. Don't over-tighten screws- they are not very big.

Fingers crossed your tps is good. $500. I found old style ROUND connector TPS for $125. Swapped connector, it has been in service 4 years.
 
re:trigger coils.
There is a connector behind flywheel gear. It has 6 pins, in 3 pairs. If you are on your ORIGINAL trigger ass'y, you may be in trouble already. The old ones had insulation that would crumble from age and vibration. This crappy insulation, causes all sorts of grief. (speaking from experience.)

Testing: check the book. I can't remember the acceptable values. Using little jumper wires, pick the pairs and test resistance (OHMS setting). It may also be heat-sensitive. Run the boat (in the water, not on a hose) long enough to be up to temp. Pop the cover and check it again.
 
Thank you for the assistance. I will post results as soon as I can. Thanks again for the direction.
 
warning lamps illuminate and I hear an electronic beep, no horn though.

Sounds good, mercury calls the buzzer/beeper a horn signal. Tim's method is correct for testing and setting the TPS

I prefer an analog meter for testing, it's easier (IMO) to see dead spot and noise in the potentiometer. And as the manual (as Tim describes) states, a DVM is best for setting the position.

Good luck! :)
 
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