ThePog Posted May 23, 2021 Share Posted May 23, 2021 My daughter tells me her Carib is using more fuel than expected, I seem to recall a recent discussion on OS about 4A-FE water temp sensor that if faulty will cause the ECU to dump more fuel in there. She seems to think having the heater on uses more fuel too but this seems unlikely, but there might be a link... Any thoughts or advice? Quote Link to comment Share on other sites More sharing options...
tortron Posted May 23, 2021 Share Posted May 23, 2021 you could test the sensor to see if its output is correct basic stuff like tyre pressure, air filter, plugs condition would be good to check first Quote Link to comment Share on other sites More sharing options...
sidewaysickness Posted May 23, 2021 Share Posted May 23, 2021 Its definitely viable that the ecu can have its own temp sensor (euros are good for it). So if the ecu temp sensor is reading wrong the ecu will think that the car is cold and run it on open loop, essentially dumping in more fuel to be "safe" 2 Quote Link to comment Share on other sites More sharing options...
ThePog Posted May 23, 2021 Author Share Posted May 23, 2021 We have a new set of plugs for it, just have not got around to putting them in. I should probably tell her to take it to the garage for an OBD check. Quote Link to comment Share on other sites More sharing options...
sidewaysickness Posted May 23, 2021 Share Posted May 23, 2021 If check engine light isn't up, the obd check wont do shit unless you are using it to monitor real time outputs, like what is engine temp reading vs actual engine temp Quote Link to comment Share on other sites More sharing options...
ThePog Posted May 23, 2021 Author Share Posted May 23, 2021 3 minutes ago, sidewaysickness said: If check engine light isn't up, the obd check wont do shit unless you are using it to monitor real time outputs, like what is engine temp reading vs actual engine temp What is the point of the OBD then? Just as I thought, a complete fucking waste of everyone's time. I will ask her some temperature related questions but when i tested it after the cam belt change it seemed completely normal. Quote Link to comment Share on other sites More sharing options...
sidewaysickness Posted May 23, 2021 Share Posted May 23, 2021 I wouldn't go that far, Its not a waste of time if one is not a complete muppet when it comes to electronics, but like I said with the Dynafari wiring, It aint no thing but a chicken wing. If it is the ecu temp sensor thats faulty then the average driver will not know any difference, temp gauge may be reading correctly but (for example) ecu sensor isn't reading over 70c and needs to get to say 86c before switching to closed loop fueling 5 Quote Link to comment Share on other sites More sharing options...
ThePog Posted May 23, 2021 Author Share Posted May 23, 2021 24 minutes ago, sidewaysickness said: I wouldn't go that far, Its not a waste of time if one is not a complete muppet when it comes to electronics, but like I said with the Dynafari wiring, It aint no thing but a chicken wing. If it is the ecu temp sensor thats faulty then the average driver will not know any difference, temp gauge may be reading correctly but (for example) ecu sensor isn't reading over 70c and needs to get to say 86c before switching to closed loop fueling I might just chuck a new sensor in there for shits and giggs 3 Quote Link to comment Share on other sites More sharing options...
sidewaysickness Posted May 23, 2021 Share Posted May 23, 2021 3 minutes ago, ThePog said: I might just chuck a new sensor in there for shits and giggs They are generally pretty cheap Quote Link to comment Share on other sites More sharing options...
ThePog Posted May 23, 2021 Author Share Posted May 23, 2021 $115 genuine Toyota, be here tomorrow. Quote Link to comment Share on other sites More sharing options...
Spencer Posted May 23, 2021 Share Posted May 23, 2021 Its a old ECU on a lower spec car, newer ones have better systems to pick up a faulty sensor. A shitty O2 sensor also is a go for fuel usage on 4ages sometimes. You should be able to find a manual (they are bundled with the 4AG ones which exist on the net) and trouble shoot the various ECU things pretty easy, if you find a factory manual it will have some flow charts on what to check first for excessive fuel usage. 1 Quote Link to comment Share on other sites More sharing options...
kyteler Posted May 23, 2021 Share Posted May 23, 2021 PM Inbound. Quote Link to comment Share on other sites More sharing options...
sidewaysickness Posted May 23, 2021 Share Posted May 23, 2021 53 minutes ago, ThePog said: $115 genuine Toyota, be here tomorrow. Fucking hell! why are genuine BMW ones like $16? 2 Quote Link to comment Share on other sites More sharing options...
ThePog Posted May 23, 2021 Author Share Posted May 23, 2021 6 minutes ago, sidewaysickness said: Fucking hell! why are genuine BMW ones like $16? Toyota tax. It will get her into the groove for spending money on sensors every 5 minutes when she buys a newer car.... Quote Link to comment Share on other sites More sharing options...
Valiant Posted May 24, 2021 Share Posted May 24, 2021 Is the thermostat working correctly? 1 Quote Link to comment Share on other sites More sharing options...
ThePog Posted May 24, 2021 Author Share Posted May 24, 2021 28 minutes ago, Valiant said: Is the thermostat working correctly? It's a Corolla, I just assumed everything was working adequately. 2 1 Quote Link to comment Share on other sites More sharing options...
Valiant Posted May 24, 2021 Share Posted May 24, 2021 Where does the temperature gauge needle sit when it's at operating temperature? Quote Link to comment Share on other sites More sharing options...
ThePog Posted May 24, 2021 Author Share Posted May 24, 2021 13 minutes ago, Valiant said: Where does the temperature gauge needle sit when it's at operating temperature? Smack in the middle of the gauge apparently. 1 Quote Link to comment Share on other sites More sharing options...
Valiant Posted May 24, 2021 Share Posted May 24, 2021 Not the problem then. Quote Link to comment Share on other sites More sharing options...
kws Posted May 24, 2021 Share Posted May 24, 2021 10 hours ago, ThePog said: What is the point of the OBD then? Just as I thought, a complete fucking waste of everyone's time. I will ask her some temperature related questions but when i tested it after the cam belt change it seemed completely normal. A 4AFE Carib wont be "OBD" it'll be toyotas old diagnostic protocol with a plug under the bonnet. You can short terminals and count flashes of the engine light to see if there are codes, otherwise there is/was an old diagnostic tool that Toyota might have that can give live data. Its nothing like OBD2 though. If its a similar sensor to a Blacktop 4AGE this is the procedure for testing it. Im 2 for 2 on Corollas with buggered thermostats too. Comes up to temp when sitting, but real slow to come up when driving and will start to drop on the gauge as you drive. First one was stuck open, I'll bet this one is too. 2 2 Quote Link to comment Share on other sites More sharing options...
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