Is she choking?

Ok good evening ladies and gents, moderators dont tell me off I am starting a new thread although related to another of mine (judder) its gone on a bit of a tangent and I would like to refocus the conversation and put a call out to your invaluable collective knowledge.

I have titled this thread "Is she choking" because one I know it will get your attention and two I think this MAY be what is going on?

I am a new owner of a under-cared for A2 1.4tdi 75 bhp 2004 reg 92000 miles on the clock.

The issue I am going to outline (hopefully better than I did previously here) I have since taking ownership of the A2, since then I have switched alloys to 15" pepperpots with 195/55 tyres (premium grade all weather NEW), new front discs and pads, replaced seized cylinders on rear drum brakes, oil level and temp sensor replaced, fuel temp cables replaced (sheared), loose bolts on drive shaft tightened up, engine bay checked no fuel leak etc and a small amount of play in engine mounts but not enough to have an effect or warrant replacing.

The issue is that in when I accelerate in a reasonable manner, ie not putting my foot through the floor, there is a hesitation almost like the engine as a cough and can take enough air in, this hesitation leads the the sympton I detected from the word go a "judder" or "shudder". Its soooo hard to explain in words but I can only describe it as after the hesitation the "judder" is mostly due to a sudden step in power to the wheels and the wheels are strugling to keep down to the road like skurrying squirrel.

This lurching/judder in not relative to road surface, incline of road or temperature. The only common thing is rate of acceleration, the ONLY way I can avoid it is to accelerate ever ever ever so gradually and slowly, and I know this is good for fuel economy it is painful to drive this way and like I said in my first post on this forum "I want to love this car" but I'm not feeling the love in my 120 miles a day at the moment!

So I am open to your thoughts, my thoughts are:

1. I hate EGR's and i have had issues with them on other cars, could this be the issue ? (hence the title of this thread)
2. The timing belt is 50000 miles and pushing 9 years old ( and I dont think the tensioners and water pump were changed then either), could it be this?
3. The clutch has not been replaced ever, so 15 years old and 92000 miles on it, could it be this?
4. When I took it for a little tune-up to see what happened when I drove it like I stole it, very aggressive acceleration up on the rpm in low gears at higher speeds, there is a definite and prolonged (seriously bad in 3rd at 30-40mph) LAG in acceleration like the turbo is working intermittently.... again I dont drive like this I was seeing how severly I could duplicate the issue I am having..... could it be this?

I'm sure some of you are rolling your eyes, I'm genuinely looking for your help to try and make driving the A2 pleasurable since I'm it for upto 3 hours a day!

Many thanks in advance.
 

Halduck

Member
Get that cambelt changed asap. I've spent 48hrs+ plus of tinkering time after mine snapped. It required a new head, so essentially a full rebuild.

Make sure you change the tensioner and idler and pump too, as the tensioner is what failed on mine as the previous tight arse owner only did the belt

Sent from my SM-G930F using Tapatalk
 
ok, taken on board, but do you think this is the route for what I am describing, or 'just' that you strongly recommend this based on your previous bad experience (similar to mine on a french car). cheers
 

audifan

A2OC Donor
Are your tyres directional and round the correct way? Does the ASR light come on on the dash? Any other warning lights? How old is the fuel filter? How old is the air filter?Are the wheel bolts torqued? Get the car scanned and post the results here.
 

Proghound

Admin Team
Watching this one. Not suffering from it myself (EGR mapped out for starters) but SWMBO's '05 Yaris diesel does very similar, more so with load in the car. We've had it from 3 years/under 10k miles and it used to have very linear power delivery.
 
"Are your tyres directional and round the correct way? "
> Im 99 percent sure directional and all correct way round, but Ill check in the morning.
"Does the ASR light come on on the dash?"
> It did on one occasion bu to be fair it was whilst cornering, not relative to acceleration, but Ill keep an eye on it and test on my commute tomorrow.
"Any other warning lights?"
> No, none.
"How old is the fuel filter? How old is the air filter?"
> from the service record and service history oil and air filter were done in 2017 at 80000 miles (12000 miles ago)
"Are the wheel bolts torqued? "
> i presume you mean fitted at the correct torque setting, I can only presume so by the mechanic.
"Get the car scanned and post the results here. "
> I will but I was hoping for others to have had a similar experience to shortcut the troubleshooting, but the things I think it might be I THINK WOULD NOT COME UP ON A COMPUTER DIAGNOSTIC?

On a side note I just noticed that in 2016 the alternator pulley was replaced, cant think this has anything to with it though?

Cheers
 
Hi Proghound, in you saying " (EGR mapped out for starters) " do you mean you have kept the egr in the car but take out all the intenal compoents so it effectively a chamber (i think someone here has done this?) or have you had it capped off and then remapped to bypass it?

Does your Yaris have an EGR, and do you think that car might just be choking due in part to egr but just because its full of carbon?

I have done Terraclean before on other vehicles (de-carb process) with mixed results.
 

O07JESTER

Member
I had similar symptoms on my vw touran.in that case it was a worn control arm bush.Before I had it changed I was reluctant to accelerate hard as it made the nearside wheel bounce rapidly.might be worth a check anyway.Not sure about the hesitation,could be sticky intake valve?.
 
The "hesitation" feels very much like turbo lag, I'm presuming this little engine is quite dependent on the turbo to give it the guts when it needs it?
That said could it be the clutch, ie high revs equaling no acceleration then sudden kick on and then I think the wheels struggle with the sudden aggressive surge of force, like i said the clutch is 90k and 15 years old? Ill have the mechanic check all bush/link arms etc just in case.... I was really hoping for this to be a common A2 issue and it be glaring obvious what the solution is?
 

Proghound

Admin Team
Hi Proghound, in you saying " (EGR mapped out for starters) " do you mean you have kept the egr in the car but take out all the intenal compoents so it effectively a chamber (i think someone here has done this?) or have you had it capped off and then remapped to bypass it?

Does your Yaris have an EGR, and do you think that car might just be choking due in part to egr but just because its full of carbon?

I have done Terraclean before on other vehicles (de-carb process) with mixed results.
No, all the EGR hardware is still there on my car, but I'm running a non-OEM map that bypasses it, so it's not activating any more or getting any worse. I could now take it out and remove all the internals if I wanted to. I suspect SWMBO's Yaris EGR is indeed choked up with carbon, it's been a short-trip car for the last 11 years. It has the hesitation when you boot it but it doesn't have the shudder afterwards.

Looking at your other questions, I'd be inclined to discount the clutch. Even if there's judder on bite, it would connect firmly once in unless it's worn enough to slip. If that were the problem, you'd notice the revs increasing with no increase in your speed if it couldn't handle the torque on acceleration.

You didn't answer about the fuel filter (only oil and air filters). The fuel filter can get clogged up with black jelly that restricts the fuel pressure supplied to the injectors. Be VERY careful when doing the plastic drain screw back up, it's very fragile so it barely wants to be finger-tight - about 2nm. @depronman manufactures a very worthwhile replacement for it.

The other thing that springs to mind if you have a heavy vibration once the torque comes in, is a driveshaft.

Best of luck with it anyway, hope your mechanic finds something to work with :)
 
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good point on fuel filter cant see any evidence of it being replaced, and consider the lack of care in general and the fact I dont trust the service pre to sale from where I bought it from, I think when i have some money (fair wack already spent beyond my hope) ill replace all service items with decent new.

tell me if im wrong I know the remap bypasses the egr, but isnt it still a restriction, ie if its clogged up?

as a test for now how easy is it for me to get to the egr, take it out do a full clean and re-insert, I will probably go down the remap route but once I have some money.
 

depronman

A2OC Donor
not likely to be clutch I changed one at 272K miles because the release bearing let go, the spinner had another 100K miles left in it, so even if abused the clutch will be fine at 92K miles
 

depronman

A2OC Donor
fuel filter is likely cause, fuel starvation, but if you boot in in low gears does it keep the revs up once past the stutter ? if so less likely to be fuel filter, but still not impossible - the aluminium drain screw is £23 + £3 postage if you want one, the plastic screw nearly always breaks as brittle now and a crap design to boot

Cheers,
 

timmus

A2OC Donor
Upon reading the first post, my first thought was 'fuel filter'. It seems I'm not the only one to have had that thought. :)

Cheers,

Tom
 
Ok minor update. Tyres are directional and are in correct direction and NO ASR light come on dash when it happened again this morning a few times! Not even being that aggressive.
 

Halduck

Member
Change the fuel filter, and add a bottle of redex diesel treatment and a 200ml of two stroke oil with this spec API TC + ISO L-EGC + JASO FC to a full tank of cheap diesel.

The oil helps to lubricate the pd injectors and clean the injector tips. Noticeably smother running after running two tanks as above. Probably won't fix your problem but worth a punt as its inexpensive and good in the long run

Sent from my SM-G930F using Tapatalk
 
I have raised this in a seperate thread focussing on clutch but wonder if the two are related. Yesterday had an horrendous trip home with stop start traffic a lot of clutch work required. By the time I got home my leg was in bits sooooooo much resistance against me pushing the clutch pedal and getting increasingly difficult to get it to take gear without stalling it! This again leads me to think 2 things relevant to clutch 1 the slave cylinders are duff and the clutch is near end of life (15 years 90000 miles). I'm pointing this out on this thread and this might be contribute to the delay in power follow through ie foot to floor on accelerator revs climb acceleration does not until sudden shoot forward? Still wondering on the turbo and yes I am getting the fuel filter and tuning sorted. Honestly hated the a2 last night.
 

audifan

A2OC Donor
Try bleeding the slave clutch cylinder to see if that improves the pedal "weight". When was the brake fluid last replaced? worth flushing the whole system, just do not let the level go too low, if the ABS pump gets air in it you will need VCDS to prime the pump. The brake fluid is often not replaced when it should be. Go for the cheaper options first before you start thinking about the clutch, slave cylinder could be failing due to lack of maintenance.
 
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