SMT or clutch problems?

[Bosse]

Hello!

Ibought my MR2 with SMT in October 2010 and drove a few weeks before I parked it for 4-5 months. Started the car the day before yesterday, after charging the battery. The car jumps as if it misfires when I press the accelerator. It feels like a traction control operation. I have no anti-spin what I know of this car from 2001. It feels like the ignition misfires if you know what I mean. At idle, when I press the accelerator, it is no problem at all. Idle speed is constant. When I release the gas when I run I feel like it misfires or does not get any gasoline.

When I got up to speed, it is no fault on the acceleration at all. I can hear a humming noise at idle, which I think has to do with hydraulic pump that I do not recognize then when I bought the car. A humming recurring at regular intervals. Somebody said it was moist in the sparkplugs holes but there is no moist and I have cleaned everything anyway.

Help.

Google Translate helpt me translate from swedish to english...

[nelix]

Hi, your translation is fine.
Hopefully someone here can help but it is also worth posting on spyderchat as well, cap weir has a lot of knowledge on the smt.

[carl_evs]

I have had a similar problem when I had my car stored, i also have an SMT. Whilst i had mine stored we had removed and modded the throttle body as well.
Once i had it back working it ran very rough and was hunting and misfirng like you mentioned. I removed the MAF and cleaned that as well as ensuring there was no dirt in the throttle body at the butterfly valve. It still ran a little rough on start up but once the ECU had relearned the fuel trims this disappeared and hasn't been a problem since.

Search for 'How to clean the MAF' and this will get you started.

With the SMT when you open the drivers door after being away from the car you should hear the hydraulic pump priming the SMT system and you may occasionally hear it chargin whilst running - especially if you have been up and down the gears a fair bit (I know mine does at least). I don't think your problem is SMT specific as all that really entails is changing the gears and not the operation of the engine - for all intents and purposes they are separate from one another - if you were experiencing SMT or actuator difficulties I would expect you to be seeing problems with gear changes and such.

[nelix]

Maf clean,

http://www.spydermagazine.com/2002/Marc ... _clean.htm

[markiii]

if you rev in neutral doesit still do it?

[Bosse]

if you rev in neutral doesit still do it?

No problems at all then.

[markiii]

i doubt its a misfire then

[Bosse]

I have had a similar problem when I had my car stored, i also have an SMT. Whilst i had mine stored we had removed and modded the throttle body as well.
Once i had it back working it ran very rough and was hunting and misfirng like you mentioned. I removed the MAF and cleaned that as well as ensuring there was no dirt in the throttle body at the butterfly valve. It still ran a little rough on start up but once the ECU had relearned the fuel trims this disappeared and hasn't been a problem since.

Search for 'How to clean the MAF' and this will get you started.

With the SMT when you open the drivers door after being away from the car you should hear the hydraulic pump priming the SMT system and you may occasionally hear it chargin whilst running - especially if you have been up and down the gears a fair bit (I know mine does at least). I don't think your problem is SMT specific as all that really entails is changing the gears and not the operation of the engine - for all intents and purposes they are separate from one another - if you were experiencing SMT or actuator difficulties I would expect you to be seeing problems with gear changes and such.

Thanks!

I've notisted that sound when I open the drivers dorr as well and knew that that must be the hydralic pump. I really hope that the problem is as described. When i drow the car when i bought it everything just work just fine. I just love the SMT-gearbox! Never had a sportscar before and this is really a economic car to driv and i like that...

[Bosse]

i doubt its a misfire then

I don't think so. It was just a way to describe the symtom. Sorry for my english. I speak it better then i write it...

[Bosse]

The car i guestion: garage.php?mode=view_image&type=garage_gallery&image_id=285

[aaronjb]

i doubt its a misfire then

I don't think so. It was just a way to describe the symtom. Sorry for my english. I speak it better then i write it...

Don't worry, it's a lot better than anyone's Swedish is here, I'll bet

[Bosse]

The sensor in now shining but i still have my problem...

[mrzwei]

The sensor in now shining but i still have my problem...

Which one? Is it the engine one (picture of an engine) or the SMT one (picture of a gear wheel with an '!' in the middle)?

[nelix]

The sensor in now shining but i still have my problem...

Which one? Is it the engine one (picture of an engine) or the SMT one (picture of a gear wheel with an '!' in the middle)?

I think he means he has cleaned the maf sensor but this has not resolved the problem.

[mrzwei]

The sensor in now shining but i still have my problem...

Which one? Is it the engine one (picture of an engine) or the SMT one (picture of a gear wheel with an '!' in the middle)?

I think he means he has cleaned the maf sensor but this has not resolved the problem.

Got it!

[Bosse]

How can a car just standing still for 4-5 months behave like mine do? I scratch my head, google like a maniac and feel like just open the engine compartment isn't something i should be doing with a Toyota. The Toyotas I had so far has never had any problems. Not any MR2 but other Toyotas.

[Bosse]

I tried one thing just now. I started the engine, put in reverse and pulled the handbrake. (then i did the same thing in first gear with the same resault) When i just put the foot just a little on the accelerator it's like the car jerks and then realese and goes on like that. At the same time I can hear a (what I think is something with the hydralic clutch) bussing short sound in regular 1 sek intervalls. I've read something about a accutank or what it's called. Maybe the pressure is not building up properly? But it takes about 20 sek when i open the dorr untill the pump stops. Matbe it's not the same thing?

I'm thinking that the problem is that the clutch don't really gets full pressure when I hit the accelerator but it's enough pressure when driving at higher speeds. Well i'm just thinking out loud! I have always fixed my cars by my self with just the cost for the replacments parts so i don't want to leave the car at a shop and pay for the work.

[Fatbloater]

Hi,

This may be completely unrelated to the problem you are experiencing.
However, I used to own an Audi A4 with a CVT (Automatic) gearbox.

There is a common fault with those vehicles whereby the vehicle can start jerking when accelerating and it is caused by one of 3 problems.
1. CVT Fluid (Transmission fuid) needs changing very regularly as it gets tiny metal filings in it over time.
2. Transmission control unit fault.
3. Clutch failure.

Now I know we're dealing with a completely different vehicle here and I'm no mechanic but I just thought I'd mention it.
Someone who knows these gearboxes will be along to comment soon hopefully but maybe its worth replacing the transmission fluid ?

Cheers
Fatbloater

[mrzwei]

My pump takes about 20 seconds to build up pressure after opening the door and you can also hear it at times when driving so this is normal.
The short buzzing sound at one second intervals usually means that either a gear has not engaged properly (usually when trying to put it into reverse so you have to try again or when you are trying to drive in too high a gear so you have to change down. Also if you leave it in 'S' when stopped for over 90 seconds without putting your foot on the brake).

Does the SMT warning light come on when you turn the key and then off go and stay off after about 5 seconds?
Also you may want to check the hydraulic fluid level but you have to take the air filter housing off to do it. If you can change gear normally when driving then I doubt that this is the problem.
Very low outside temperatures will also affect the gear change.

[Bosse]

Can low level of hydralic fluid cause my problem? is there a way to reset any DCU or computer fjust for the gearbox or is pulling of the negativ cable on the battery reseting all computers?

[Bosse]

My pump takes about 20 seconds to build up pressure after opening the door and you can also hear it at times when driving so this is normal.
The short buzzing sound at one second intervals usually means that either a gear has not engaged properly (usually when trying to put it into reverse so you have to try again or when you are trying to drive in too high a gear so you have to change down. Also if you leave it in 'S' when stopped for over 90 seconds without putting your foot on the brake).

Does the SMT warning light come on when you turn the key and then off go and stay off after about 5 seconds?
Also you may want to check the hydraulic fluid level but you have to take the air filter housing off to do it. If you can change gear normally when driving then I doubt that this is the problem.
Very low outside temperatures will also affect the gear change.

I recognize everything you'r saying about warning light and they do come of after starting the engine. Also the pump starting when open the drivers door. 20 sek and the pump stops. When I'm talking abaout a buzzing sound I don't mean the sound that comes from leaving in gear for more than 90 seconds or when in reverse.

It's a buzzing sound coming from the engine compartment in regular intervalls when hiting the accelerator. My english is not that good. Buzzing is maybe the wrong word to describe it. The car behaves like if you have anti spin on a car standing on ice and the system is at work. The tyres trying to get a grip, releases and trying again. But as I think I've written: If I hit the accelerator some more the car accelerates just fine.

[SteveJ]

If the car has been sitting for 5 months with a flat battery the SMT ECU needs to be told to re-learn the clutch bite point.

The process is documented somewhere (used to be on the old MR2ROC site but it's not here any more) but I wouldn't do it on a car with an old clutch as it is rather hard on it!

[Bosse]

If the car has been sitting for 5 months with a flat battery the SMT ECU needs to be told to re-learn the clutch bite point.

The process is documented somewhere (used to be on the old MR2ROC site but it's not here any more) but I wouldn't do it on a car with an old clutch as it is rather hard on it!

That was some news! The clutch bite point? Just what i don't have! I'm gonna google some more...

[mrzwei]

Details of the relearn procedure for the SMT are here, around page 20):
http://www.ariclim.com/files/mr2spyder/SMT.pdf

[SteveJ]

Nope - that one isn't what the dealers use now (it was the original document which resulted in the clutch not disengaging properly). It was superceded by a service bulletin which involves chocking the wheels and attempting to drive the car forward until the buzzer sounds. I dont recall the exact details of the process though.

[mrzwei]

My apologies

[Bosse]

Nope - that one isn't what the dealers use now (it was the original document which resulted in the clutch not disengaging properly). It was superceded by a service bulletin which involves chocking the wheels and attempting to drive the car forward until the buzzer sounds. I dont recall the exact details of the process though.

I just hit the break and hit the accelerator until the buzzer sounded and the engine stopped (naturally it does) and turned of the ignition. Started the car again and it's better now when i hit the accelerator but not totally. I would like to know the whole process.

[Bosse]

My apologies

Not to worry mate. It's the effort to help me that counts!

[Bosse]

I haven't checked the hydralic fluid level. Because I have to disamble thing to do that. Can low fluid level cause my problem maybe?

[mikecobra427]

Imho it is unlikely to be the fluid level if the pump only runs for approx 20 seconds and the noise the pump makes has not changed to a higher pitched noise. ~The only way to find out though is to take the air filter off and have a look.

It is more likely to be a bit of surface rust of the flywheel and clutch face (it has metal embeded into the friction material). I have another car with an old rover 3.5 V8 engine in it and after it was stood for a long time the clutch and flywheel became stuck together and had to be rocked in gearto get them to part. Initially after this the clutch would bind a little and jump into gear until this was worn off. In a manual car this is possible by just slipping the clutch a bit to clean off the crap but in the smt this is not possible. This is likely to improve with time as the clutch beds back in.

Hope this is all that is wrong with it.

Mike