Erratic Revs On Idle, Sometime Stalls

[wr1472]

hi all

this is my first post, I've just bought my first celica (7th Gen i think, 2001). It has a few probs with it. Mainly on idle the revs are all over the place, and sometimes it stalls. I'm a newbie when it comes to cars so not exactly sure what it could be.

I've booked it in at Mr T for a diagnostics test (gonna cost me 40 squid is that cheap?), I'd like some independent opinions from some seasoned celica owners.

I'm using redex fuel injection cleaner in the fuel, just a slight improvement I think - hard to tell cos I've only been driving the car a few days. Is it the fuel pump, injector, ecu...? If so any idea how much to replace or fix - ball park figure.

The guy I last bought it off says he had a non-toyota garage look at it and reckoned a full service by Mr T would fix the prob. Car was serviced in Jan, it was imported in 2004 by himself and its done 77000 miles.

I got a good price on the car I think, and these faults were also taken into consideration with the price. Other than that the cars great inside and out!

Any feedback will be welcome.

Cheers

[Bibbs]

You should be able to check the ECU for error codes .. and then re-set it. It's all Toyota will do and take £40 off you for the "honour" ..

Where in the UK are you, someone local could help?

[wr1472]

You should be able to check the ECU for error codes .. and then re-set it. It's all Toyota will do and take £40 off you for the "honour" ..

Where in the UK are you, someone local could help?

hi bibbs

I'm working in coventry during the week, upto west yorkshire at the weekend to get it serviced in bradford. How do I check for error codes/reset the ecu? I've also noticed my gearbox light comes on at highspeed driving but don't seem to notice any other difference.

[mikeb]

You should be able to check the ECU for error codes .. and then re-set it. It's all Toyota will do and take £40 off you for the "honour" ..

Where in the UK are you, someone local could help?

It's a gen7 - which needs diagnostics kit to check for ECU errors. ;)

I got a good price on the car I think, and these faults were also taken into consideration with the price. Other than that the cars great inside and out!

How do you know you got it for a good price, if you don't know what the fault is? If it's a sensor, then you might have a warning light on the dash (probably the one with an engine symbol). TBH it could be just about anything, but fueling is the last thing I would be suspecting. Possibilities include (in no particular order):

ignition fault (dodgy ht lead/plug)

idle control valve

crank position sensor

knackered engine internals (!) - do a compression check.

If Mr T will guarantee to identify the fault for £40, in your situation I would go that route.

[wr1472]

You should be able to check the ECU for error codes .. and then re-set it. It's all Toyota will do and take £40 off you for the "honour" ..

Where in the UK are you, someone local could help?

It's a gen7 - which needs diagnostics kit to check for ECU errors. ;)

I got a good price on the car I think, and these faults were also taken into consideration with the price. Other than that the cars great inside and out!

How do you know you got it for a good price, if you don't know what the fault is?

If it's a sensor, then you might have a warning light on the dash (probably the one with an engine symbol).

TBH it could be just about anything, but fueling is the last thing I would be suspecting. Possibilities include (in no particular order):

ignition fault (dodgy ht lead/plug)

idle control valve

crank position sensor

knackered engine internals (!) - do a compression check.

If Mr T will guarantee to identify the fault for £40, in your situation I would go that route.

4500 squid for 51 plate (140bhp), 77000 miles (majority of which are m'way miles) full service history here and Japan (imported in 2004), bodywork in good knick and interior??? Knocked few hundred off agreed price after seeing these faults.

I reckon whatever prob is hopefully a few hundred will solve it, which would still mean I got good price.

light does come on at high speed, if that is the engine fault light, which I thought might be gearbox light - manual's in Japanese so hard to tell!

Yeah I'm def going to do that unless by some miracle it gets sorted by the weekend.

[ozzy666]

lo,i had the same fault with a car i had but it was'nt a toyota,it was a peugeot 206. it kept erratically idling at any time and cutting out when stationary.i took it to 2 garages for diagnostic check and they found no error! so i took it to recommended garage my m8 goes to and the bloke found out that the temp sensor was not working correctly all the time .one minute it was ok then the next it would shoot up then shoot back down,the car did'nt know where it was, so it was forcing more petrol in when it should'nt be.hope this is all it is m8 cost me £45 for the test and £18 for new sensor.

i tried the top 3 suggestions mikeb has put,dint help the matter.

[wr1472]

lo,i had the same fault with a car i had but it was'nt a toyota,it was a peugeot 206. it kept erratically idling at any time and cutting out when stationary.i took it to 2 garages for diagnostic check and they found no error! so i took it to recommended garage my m8 goes to and the bloke found out that the temp sensor was not working correctly all the time .one minute it was ok then the next it would shoot up then shoot back down,the car did'nt know where it was, so it was forcing more petrol in when it should'nt be.hope this is all it is m8 cost me £45 for the test and £18 for new sensor.

thanks for the tip ozzy, I'll pass on all these suggestions when Mr T looks at it at the weekend, I'd be surprised if it is anything major cos once its moving its fine.

[mikeb]

lo,i had the same fault with a car i had but it was'nt a toyota,it was a peugeot 206. it kept erratically idling at any time and cutting out when stationary.i took it to 2 garages for diagnostic check and they found no error! so i took it to recommended garage my m8 goes to and the bloke found out that the temp sensor was not working correctly all the time .one minute it was ok then the next it would shoot up then shoot back down,the car did'nt know where it was, so it was forcing more petrol in when it should'nt be.hope this is all it is m8 cost me £45 for the test and £18 for new sensor.

thanks for the tip ozzy, I'll pass on all these suggestions when Mr T looks at it at the weekend, I'd be surprised if it is anything major cos once its moving its fine.

Like I said - it could be just about anything. But I would hope that the gen7 ECU can pick up most faulty sensors, even intermittent ones if they go out of range.

One of my previous cars had similar symptoms to yours (it wasn't a celica, or even a toyota), and it turned out that the piston rings had failed on at least one cylinder. When moving it ran fine - but it wouldn't idle. I don't mean to make you worry (the 1zz is a pretty strong engine and well protected from abuse), but it is a remote possibility that there is a mechanical problem with it. And then your bargain price isn't so much of a bargain anymore.

[wr1472]

lo,i had the same fault with a car i had but it was'nt a toyota,it was a peugeot 206. it kept erratically idling at any time and cutting out when stationary.i took it to 2 garages for diagnostic check and they found no error! so i took it to recommended garage my m8 goes to and the bloke found out that the temp sensor was not working correctly all the time .one minute it was ok then the next it would shoot up then shoot back down,the car did'nt know where it was, so it was forcing more petrol in when it should'nt be.hope this is all it is m8 cost me £45 for the test and £18 for new sensor.

thanks for the tip ozzy, I'll pass on all these suggestions when Mr T looks at it at the weekend, I'd be surprised if it is anything major cos once its moving its fine.

Like I said - it could be just about anything. But I would hope that the gen7 ECU can pick up most faulty sensors, even intermittent ones if they go out of range.

One of my previous cars had similar symptoms to yours (it wasn't a celica, or even a toyota), and it turned out that the piston rings had failed on at least one cylinder. When moving it ran fine - but it wouldn't idle. I don't mean to make you worry (the 1zz is a pretty strong engine and well protected from abuse), but it is a remote possibility that there is a mechanical problem with it. And then your bargain price isn't so much of a bargain anymore.

fingers crossed its not mechanical then! I will keep you guys posted on what Mr T says. thanks

[Bibbs]

You should be able to check the ECU for error codes .. and then re-set it. It's all Toyota will do and take £40 off you for the "honour" ..

Where in the UK are you, someone local could help?

It's a gen7 - which needs diagnostics kit to check for ECU errors. ;)

Doubt it. (But happy to be proved wrong).

It'll have a std OBD II system and a Toyota specific interface.

A part of the OBD II spec is that you ground one of the pins and the ECU error code will flash on the dash.

I heard exactly the same thing about the S2000 - "Can't be done" .. so I got out a paper clip and googled the specs, went and checked the car and get an error code that I then resolved.

No £40 to Honda, no being fobbed off and one car that then ran smooth as you like ..

[Bibbs]

Can someone with a Gen7 get a pic of the interface up on the forum?

One of the front, and then one of the back (unscrew it) so I can see the wires. I should then be able to assist.

It had to be clearly marked, assesable without tools and within 1m of the steering wheel (apparently).

Apparently on all US cars after '96 and all EU cars by '01.

Here for more info.

The port is about 1" long ..

[mikeb]

Can someone with a Gen7 get a pic of the interface up on the forum?

One of the front, and then one of the back (unscrew it) so I can see the wires. I should then be able to assist.

It had to be clearly marked, assesable without tools and within 1m of the steering wheel (apparently).

Apparently on all US cars after '96 and all EU cars by '01.

Here for more info.

The port is about 1" long ..

I don't think pin 9 is an official part of the OBD2 specs - it looks more like something honda put in as an optional extra. AFAIK toyota haven't done the same, and if they have I've never seen the codes published. The codes for standard OBD2 can be found here:

http://www.obdii.com/codes.html

But they can only be retrieved by connecting up some device that can read data off the interface. They are all 4 digit numbers with a 'P' prefixed.

[Bibbs]

The port may well be different .. that was just an example ..

But I believe that the ability to DIY error codes is something that is standard.

I'm happy to be "proved" wrong .. anyone wanna lend me their Gen7? 10mins, in Reading.

And it's the reason I want a pic of the front and the rear - to check the wiring setup ..

[wr1472]

Can someone with a Gen7 get a pic of the interface up on the forum?

One of the front, and then one of the back (unscrew it) so I can see the wires. I should then be able to assist.

It had to be clearly marked, assesable without tools and within 1m of the steering wheel (apparently).

Apparently on all US cars after '96 and all EU cars by '01.

Here for more info.

The port is about 1" long ..

I don't think pin 9 is an official part of the OBD2 specs - it looks more like something honda put in as an optional extra. AFAIK toyota haven't done the same, and if they have I've never seen the codes published. The codes for standard OBD2 can be found here:

http://www.obdii.com/codes.html

But they can only be retrieved by connecting up some device that can read data off the interface. They are all 4 digit numbers with a 'P' prefixed.

I tried stickin a paper clip in pin 9 - or what I think is pin 9 and earthing it on a nearby bolt but nothing happened so either it doesn't work or i'm doing it wrong. It was dark and freezing outside so I didn't really spend that long trying!

[Bibbs]

that's why I need a pic of the back of it .. to confirm it's wired up.

you earthed it and turned the ingition on full (not started the engine though)?

[wr1472]

that's why I need a pic of the back of it .. to confirm it's wired up.

you earthed it and turned the ingition on full (not started the engine though)?

yeah earth on bolt nearby

turned ignition full but not started it, all dash lights come up as normal but thats it. Maybe I didin't do it right, like I sed dark, cold and I'm stuck in a hotel this week so its difficult to do.

[mikeb]

that's why I need a pic of the back of it .. to confirm it's wired up.

you earthed it and turned the ingition on full (not started the engine though)?

yeah earth on bolt nearby

turned ignition full but not started it, all dash lights come up as normal but thats it. Maybe I didin't do it right, like I sed dark, cold and I'm stuck in a hotel this week so its difficult to do.

I am at least 95% sure that the paperclip trick and flashing MIL light won't work. It's a proprietary system that Honda used in some of their cars - it is NOT part of the OBD2 specification. Toyota may have their own way of achieving the same (although I've no idea why the would bother - they want you to take the car to them for diagnosis), but to my knowledge it's not publically documented.

On another note, the bonus of OBD2 is that it's an open standard for diagnostics - anyone can buy the plug in tool. For most DIYers it's an expensive option, but any semi decent garage should have the kit. So you don't have to got to a Mr T dealer, but other places might do the diagnostics for free and then make their money by selling you the parts to fix it.

[wr1472]

Just got car back from mr t.

they did a diagnostics check, error codes p0340 (camshaft position circuit sensor) and p1346 (vvt sensor) errors came up. guy there said they're located right inside the engine so it would take a while to get to it (about 5 hours), to exactly pin point problem.

He also said engine oil was quite low, the fault could be making it burn oil.

A service may solve the problem but not a guarantee.

Not sure what to do now, will an independent garage be able fix prob? mr T charge 80 odd squid an hour for labour.

[mikeb]

Just got car back from mr t.

they did a diagnostics check, error codes p0340 (camshaft position circuit sensor) and p1346 (vvt sensor) errors came up. guy there said they're located right inside the engine so it would take a while to get to it (about 5 hours), to exactly pin point problem.

He also said engine oil was quite low, the fault could be making it burn oil.

A service may solve the problem but not a guarantee.

Not sure what to do now, will an independent garage be able fix prob? mr T charge 80 odd squid an hour for labour.

I don't see how a standard service will fix either of those two? And I'd be sursprised if any electrical fault was making the engine burn oil. Whatever, it needs topping up.

Yes, an independent garage should be able to fix it, there may be some damaged wiring somewhere, it seems a bit odd that there are two faulty sensors (although they could be the same thing). A new sensor may well be expensive (available only from Mr T probably).

[wr1472]

yeah he did say it may be faulty wiring. TBH i reckon he wanted me to stump out for a full service, then if it didn't work fork out for the fault to be fixed.

I'll take it round some independent garages at the weekend, see what they can do. Are these VVTi engines difficult for an "average" mechanic to work on - especially the two faults that have come up on mine?

will think about what to do, I really like the car, and it may be that I just sell this get my money back and buy another celica. Like I said I got a good price on it and either fixing or selling I won't lose out - just the hassle really.

BTW anyone recommend any good garages in the west yorkshire area?