Help With Beams Startup Problem

mr2nv · 02-29-2008, 01:02 PM

So I brought my car to my mechanic to finally fix the temp gauge. The car worked great, no problems, but the temp gauge would immediately spike to the top when the car turned on. My mechanic said he fixed the wiring for the temp gauge but now is having problems getting the car started. How do we isolate what the problem is? He says I might need a new temp sensor. Would the car not start if the temp sensor wasn't working correctly? The mechanic seems to think the ecu thinks the car is either too cold or too hot and is dumping too much fuel and that's why he can't get it started. What should I tell him to do to try and figure out what the problem is? Thanks.

Matt

94MR2 · 02-29-2008, 08:42 PM

Just thinking out loud here. If the motor that came in your car has the same temp sensor and reads the same parameters, you could swap them out and see if the ecu reads it and maybe that would solve your problem. Try unhooking the sensor and start the car??

mr2nv · 03-03-2008, 04:13 PM

I originally had a 5sfe engine but it's long gone so no parts to swap in. I asked my mechanic why he couldn't revert the wiring back to what it had been before I brought the car in and when it worked fine except for the gauge not working, and he said it didn't work. He ended up ordering from Japan two replacement temp sensors, one for the gauge, one for the ecu. Hopefully that will resolve the issue. Anyone know the part numbers for the beams temp sensors?

MANDALAY · 03-03-2008, 04:40 PM

Unless anyone can help you now , ill send info about 10 hrs at work need my home computer.But be specific .
The way l see it you want the sensor for the radiator for the gauge and the one on the engine for the ECU , correct ?
Personally i dont know whether the engine one is beams specific ?
Ild head down to Toyota if l was you and see if the plug output is the same.
It will save you time/money

94MR2 · 03-12-2008, 02:12 PM

Now I have the exact same problem. As soon as I start the car the gauge pegs to H and I know there is no way it is running that hot especially in this 30 degree weather.....So did you get it fixed? For the mr2 does the gauge read from the water neck or the radiator itself??

94MR2 · 03-12-2008, 02:27 PM

Ok after more searching it looks like I need to ground out the gauge? What exactly did your mechanic do?

Thanks

mr220v · 03-12-2008, 02:35 PM

The mr2 has wire that runs through the fuse box that needs to be grounded for the gauge to work properly. It's on the larger connector.

mr2nv · 03-12-2008, 02:49 PM

My car is still at the mechanic waiting on the sensors from Japan. They should be arriving soon and then hopefully that will fix the problem. From what my mechanic told me, once he got the gauge working correctly the car was then having problems starting. Can someone explain the logic behind this? When the gauge used to peg to H the car ran fine but after fixing the gauge now the car won't start.

94MR2 · 03-12-2008, 02:56 PM

Thank you, I found the wire. I unplugged the sensor to see if I got the same symptoms as you did(mr2nv) The car like choked when I went to start it. I pugged the sensor back in and reset the ecu and it purrs like a kitten with no cels. Now all I have to do it ground that out thank you mr220v.

sugarfree · 03-15-2009, 07:20 PM

hey guys,

were having the same problem. When we try to start the motor it wont turn, its not firing. When we take the key out the radiator fan just stays on like its over heated and the temp gauage shoots up to H, but the car hasnt even been on.

What exactly are you doing 94mr2?

puretone · 03-17-2009, 01:31 AM

mine runs with the temp sensor disconnect...sure it runs a little rough, like limp-mode-ish, but otherwise it's fine. Make sure your temp sensor AND temp gauge are GROUNDED properly. If I disconnect my ground a the gauge, it freaks out.
You will need to reset the ECU, unplug all 4 plugs at the ECU, leave them out for at least 5 mins or more to clear everything out.

02-29-2008, 01:02 PM	#1 (permalink)
mr2nv Beams Owners Group Join Date: Mar 2007 Posts: 179 Thanks: 0 Thanked 10 Times in 8 Posts iTrader Rating: (1/100% )	Help With Beams Startup Problem So I brought my car to my mechanic to finally fix the temp gauge. The car worked great, no problems, but the temp gauge would immediately spike to the top when the car turned on. My mechanic said he fixed the wiring for the temp gauge but now is having problems getting the car started. How do we isolate what the problem is? He says I might need a new temp sensor. Would the car not start if the temp sensor wasn't working correctly? The mechanic seems to think the ecu thinks the car is either too cold or too hot and is dumping too much fuel and that's why he can't get it started. What should I tell him to do to try and figure out what the problem is? Thanks. Matt

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02-29-2008, 08:42 PM	#2 (permalink)
94MR2 Beams Owners Group Join Date: Nov 2005 Location: New Oxford, Pa Posts: 389 Thanks: 11 Thanked 7 Times in 7 Posts iTrader Rating: (12/100% )	Just thinking out loud here. If the motor that came in your car has the same temp sensor and reads the same parameters, you could swap them out and see if the ecu reads it and maybe that would solve your problem. Try unhooking the sensor and start the car??

03-03-2008, 04:13 PM	#3 (permalink)
mr2nv Beams Owners Group Join Date: Mar 2007 Posts: 179 Thanks: 0 Thanked 10 Times in 8 Posts iTrader Rating: (1/100% )	I originally had a 5sfe engine but it's long gone so no parts to swap in. I asked my mechanic why he couldn't revert the wiring back to what it had been before I brought the car in and when it worked fine except for the gauge not working, and he said it didn't work. He ended up ordering from Japan two replacement temp sensors, one for the gauge, one for the ecu. Hopefully that will resolve the issue. Anyone know the part numbers for the beams temp sensors?

03-03-2008, 04:40 PM	#4 (permalink)
MANDALAY Beams Owners Group Join Date: Feb 2007 Location: victoria AUSTRALIA Posts: 4,210 Thanks: 136 Thanked 112 Times in 107 Posts My Google Map iTrader Rating: (6/100% )	Unless anyone can help you now , ill send info about 10 hrs at work need my home computer.But be specific . The way l see it you want the sensor for the radiator for the gauge and the one on the engine for the ECU , correct ? Personally i dont know whether the engine one is beams specific ? Ild head down to Toyota if l was you and see if the plug output is the same. It will save you time/money

03-12-2008, 02:12 PM	#5 (permalink)
94MR2 Beams Owners Group Join Date: Nov 2005 Location: New Oxford, Pa Posts: 389 Thanks: 11 Thanked 7 Times in 7 Posts iTrader Rating: (12/100% )	Now I have the exact same problem. As soon as I start the car the gauge pegs to H and I know there is no way it is running that hot especially in this 30 degree weather.....So did you get it fixed? For the mr2 does the gauge read from the water neck or the radiator itself??

03-12-2008, 02:27 PM	#6 (permalink)
94MR2 Beams Owners Group Join Date: Nov 2005 Location: New Oxford, Pa Posts: 389 Thanks: 11 Thanked 7 Times in 7 Posts iTrader Rating: (12/100% )	Ok after more searching it looks like I need to ground out the gauge? What exactly did your mechanic do? Thanks

03-12-2008, 02:35 PM	#7 (permalink)
mr220v Beams Owners Group Join Date: Mar 2006 Posts: 2,529 Thanks: 13 Thanked 176 Times in 147 Posts iTrader Rating: (11/100% )	The mr2 has wire that runs through the fuse box that needs to be grounded for the gauge to work properly. It's on the larger connector.

03-12-2008, 02:49 PM	#8 (permalink)
mr2nv Beams Owners Group Join Date: Mar 2007 Posts: 179 Thanks: 0 Thanked 10 Times in 8 Posts iTrader Rating: (1/100% )	My car is still at the mechanic waiting on the sensors from Japan. They should be arriving soon and then hopefully that will fix the problem. From what my mechanic told me, once he got the gauge working correctly the car was then having problems starting. Can someone explain the logic behind this? When the gauge used to peg to H the car ran fine but after fixing the gauge now the car won't start.

03-12-2008, 02:56 PM	#9 (permalink)
94MR2 Beams Owners Group Join Date: Nov 2005 Location: New Oxford, Pa Posts: 389 Thanks: 11 Thanked 7 Times in 7 Posts iTrader Rating: (12/100% )	Thank you, I found the wire. I unplugged the sensor to see if I got the same symptoms as you did(mr2nv) The car like choked when I went to start it. I pugged the sensor back in and reset the ecu and it purrs like a kitten with no cels. Now all I have to do it ground that out thank you mr220v.

03-15-2009, 07:20 PM	#10 (permalink)
sugarfree Some Skills Join Date: May 2007 Posts: 63 Thanks: 12 Thanked 0 Times in 0 Posts iTrader Rating: (1/100% )	hey guys, were having the same problem. When we try to start the motor it wont turn, its not firing. When we take the key out the radiator fan just stays on like its over heated and the temp gauage shoots up to H, but the car hasnt even been on. What exactly are you doing 94mr2?

03-17-2009, 01:31 AM	#11 (permalink)
puretone Beams Owners Group Join Date: Aug 2006 Location: Aruba, #1 BEAMS Engine on the Island Posts: 2,339 Thanks: 28 Thanked 57 Times in 56 Posts My Google Map iTrader Rating: (1/100% )	mine runs with the temp sensor disconnect...sure it runs a little rough, like limp-mode-ish, but otherwise it's fine. Make sure your temp sensor AND temp gauge are GROUNDED properly. If I disconnect my ground a the gauge, it freaks out. You will need to reset the ECU, unplug all 4 plugs at the ECU, leave them out for at least 5 mins or more to clear everything out.