My Rolling Road Results
Discussion
Well, as close as I can get to them before I find a scanner...
Before I launch into a lengthy narrative I want to thank Charlie for his help, it was a good day out as last time. I'm looking forward to the next PH event!
So on to me. I got an interesting set of results.
As you know I was there mostly to assure myself that it wasn't about to blow up, having heard several horror stories about lean-running Blitz ECUs. My sparkplugs are showing signs of lean running and the car hesitates under gentle throttle movements.
Further evidence of light fuelling, were any needed, comes in the form of the steady 33mpg I'm getting, which from a hard-driven turbo is just plain silly.
The power figures were a distant second priority, far behind concerns about pistons escaping to seek a new life in a field somewhere.
It turns out that I'm not at risk of an engine blow out. Far from it, I'm actually running slightly rich at high revs and perfectly well at all others. That was a serious shocker...
With that out of the way attention turned to the level of boost I'm running. The Blitz is supposed to uprate boost 30-40% so I was expecting fireworks.
The measured figure was a steady 0.5bar, which is about as explosive as damp socks.
It also proves once and for all (as you've all told me repeatedly) that the standard gauge is utterly useless.
The power figures, as you'll now have realised, failed to sparkle. The car managed a pretty meagre 172bhp at the wheels (206 at the fly, 200lb-ft of torque).
So not great.
I'll put the scans up here ASAP.
Anyone got any good ideas where I should look for this missing boost?
I've checked over the car. Some hoses were pretty loose so I fixed those, I've checked and adjusted the throttle position sensor, making the car slower (doh!) and shortened the insanely long actuator vacuum hose (no longer goes from turbo to actuator via the spare tyre).
None of this has made the blindest bit of difference to the boost of course.
I checked the turbo itself. Zero axial play, free bearings but detectable radial play. Not enough to measure though (that said I'm only allowed 0.18mm, so maybe that's it?).
Any good ideas? The car is a '92 Rev 2 GT Turbo. Blitz decat pipe, Blitz Access ECU, ARC induction kit & cold box.
Right - got to go, I'm due at a training course accross town.
Later guys.
Before I launch into a lengthy narrative I want to thank Charlie for his help, it was a good day out as last time. I'm looking forward to the next PH event!
So on to me. I got an interesting set of results.
As you know I was there mostly to assure myself that it wasn't about to blow up, having heard several horror stories about lean-running Blitz ECUs. My sparkplugs are showing signs of lean running and the car hesitates under gentle throttle movements.
Further evidence of light fuelling, were any needed, comes in the form of the steady 33mpg I'm getting, which from a hard-driven turbo is just plain silly.
The power figures were a distant second priority, far behind concerns about pistons escaping to seek a new life in a field somewhere.
It turns out that I'm not at risk of an engine blow out. Far from it, I'm actually running slightly rich at high revs and perfectly well at all others. That was a serious shocker...
With that out of the way attention turned to the level of boost I'm running. The Blitz is supposed to uprate boost 30-40% so I was expecting fireworks.
The measured figure was a steady 0.5bar, which is about as explosive as damp socks.
It also proves once and for all (as you've all told me repeatedly) that the standard gauge is utterly useless.
The power figures, as you'll now have realised, failed to sparkle. The car managed a pretty meagre 172bhp at the wheels (206 at the fly, 200lb-ft of torque).
So not great.
I'll put the scans up here ASAP.
Anyone got any good ideas where I should look for this missing boost?
I've checked over the car. Some hoses were pretty loose so I fixed those, I've checked and adjusted the throttle position sensor, making the car slower (doh!) and shortened the insanely long actuator vacuum hose (no longer goes from turbo to actuator via the spare tyre).
None of this has made the blindest bit of difference to the boost of course.
I checked the turbo itself. Zero axial play, free bearings but detectable radial play. Not enough to measure though (that said I'm only allowed 0.18mm, so maybe that's it?).
Any good ideas? The car is a '92 Rev 2 GT Turbo. Blitz decat pipe, Blitz Access ECU, ARC induction kit & cold box.
Right - got to go, I'm due at a training course accross town.
Later guys.
_Al_ said:
Well, as close as I can get to them before I find a scanner...
Before I launch into a lengthy narrative I want to thank Charlie for his help, it was a good day out as last time. I'm looking forward to the next PH event!
So on to me. I got an interesting set of results.
As you know I was there mostly to assure myself that it wasn't about to blow up, having heard several horror stories about lean-running Blitz ECUs. My sparkplugs are showing signs of lean running and the car hesitates under gentle throttle movements.
Further evidence of light fuelling, were any needed, comes in the form of the steady 33mpg I'm getting, which from a hard-driven turbo is just plain silly.
The power figures were a distant second priority, far behind concerns about pistons escaping to seek a new life in a field somewhere.
It turns out that I'm not at risk of an engine blow out. Far from it, I'm actually running slightly rich at high revs and perfectly well at all others. That was a serious shocker...
With that out of the way attention turned to the level of boost I'm running. The Blitz is supposed to uprate boost 30-40% so I was expecting fireworks.
The measured figure was a steady 0.5bar, which is about as explosive as damp socks.
It also proves once and for all (as you've all told me repeatedly) that the standard gauge is utterly useless.
The power figures, as you'll now have realised, failed to sparkle. The car managed a pretty meagre 172bhp at the wheels (206 at the fly, 200lb-ft of torque).
So not great.
I'll put the scans up here ASAP.
Anyone got any good ideas where I should look for this missing boost?
I've checked over the car. Some hoses were pretty loose so I fixed those, I've checked and adjusted the throttle position sensor, making the car slower (doh!) and shortened the insanely long actuator vacuum hose (no longer goes from turbo to actuator via the spare tyre).
None of this has made the blindest bit of difference to the boost of course.
I checked the turbo itself. Zero axial play, free bearings but detectable radial play. Not enough to measure though (that said I'm only allowed 0.18mm, so maybe that's it?).
Any good ideas? The car is a '92 Rev 2 GT Turbo. Blitz decat pipe, Blitz Access ECU, ARC induction kit & cold box.
Right - got to go, I'm due at a training course accross town.
Later guys.
Two MR2 turbo's and two of them without boost!
Soz Al, still 200bhp is more than mine
I'd check to see that your factory blow off valve, which will be a plumb-back, isn't leaking. If it DOES leak, it might feed back after the AFM which means that you'll be feeding more air to the engine than there is fuel for, giving you a lean burn. It would also explain the low boost pressure. It sounds silly now that I type it out but worth checking eh? Normally a leaky BOV gives you a rich burn but thats when they're externally vented. I'm taking a punt that a leaking plumb-back could give you a lean burn... some how...
The other thing may be a sticking waste-gate actuator which would result in your exhaust being leaked from the housing when it should be boosting instead. Maybe its time for a decent size turbo and external wastegate!
The other thing may be a sticking waste-gate actuator which would result in your exhaust being leaked from the housing when it should be boosting instead. Maybe its time for a decent size turbo and external wastegate!
All the info above.
Glad you had a reasuring visit to the RR.
You can relax a bit & enjoy hunting down extra power.
Will your turbo hold vacuum consistantly? or will it drop off after a sec or 2? Even a tiny hole in tubing will cause inefficient turbo.
What is the Blitz ecu boost level supposed to be? & does it have a hi & lo level?
Assuming there are no probs it may be worth investing in an electric boost controller.
Glad you had a reasuring visit to the RR.
You can relax a bit & enjoy hunting down extra power.
Will your turbo hold vacuum consistantly? or will it drop off after a sec or 2? Even a tiny hole in tubing will cause inefficient turbo.
What is the Blitz ecu boost level supposed to be? & does it have a hi & lo level?
Assuming there are no probs it may be worth investing in an electric boost controller.
_Al_ said:
I checked the turbo itself. Zero axial play, free bearings but detectable radial play. Not enough to measure though (that said I'm only allowed 0.18mm, so maybe that's it?).
To add my two penneth on that bit. That sounds fine to me. There should be a very slight "side to side" movement (the shaft is on an oil bearing), its "in and out" play that signifies a dead turbo (incidentally, my old "dead" turbo seems fine to me, so I could be talking boswelox)
What did Charlie suggest you try next?
we need another Jap chat RR day!Charlie said it may be a sensor, making the ECU play it safe. The boost is within Toyota spec, it's just sat right at the bottom of the range.
I wondered about the wastegate myself, but as mentioned above I'd be getting lean burn and it's actually running rich on boost.
I really need to study up on how this car sets its boost level. How does the ECU control it? I know the actuator hose had a dodgy seal, but fixing that didn't improve matters.
Thing is there was just a hose from the turbo itself to the actuator and then a short one (presumably) drawing a reference vac off the engine. How does the ECU have any say in that setup?
The Blitz ECU I've got claims a 30-40% boost increase, so I should have between 0.65 and 1.16 bar. At least two people on the MR2 owners clubs have got the same Blitz ECU I have, both are happy with it.
One of them only installed it last week and says the car is much better as a result (and looking at his other posts I think he knows what he's talking about).
I'm thinking that the pointlessly long actuator hose and the other blanked-off hoses around the engine bay could be evidence that they didn't put it back together right when they removed the Greddy EBC it used to have? (Good use of grammar Al!
)
In that case, maybe the ECU isn't connected to the turbo system, causing it to run at the base 0.5 bar and no higher?
I'm guessing; but it's sort-of an educated guess.
I've gone around all of the hoses now and checked thoroughly for boost leaks. I haven't checked the intercooler itself, so I'll do that tonight if I get home in time. None of the other tubes had signs of anything that could cause a blockage, but you never know.
I understand what you're saying about electronic boost controllers, but I'd much rather trace and fix the problem - hence restoring normal power, before I go hunting for extra...
I really need to pick up that boost gauge (the one that works!).
Russ - you aren't kidding about the RR day mate! I'm hoping I'll need one pretty soon to verify she's back to full health.
Then another to see what the EBC does.
Keep the suggestions coming guys! I can't afford to have MR T go at it so I need your support!
Cheers!
I wondered about the wastegate myself, but as mentioned above I'd be getting lean burn and it's actually running rich on boost.
I really need to study up on how this car sets its boost level. How does the ECU control it? I know the actuator hose had a dodgy seal, but fixing that didn't improve matters.
Thing is there was just a hose from the turbo itself to the actuator and then a short one (presumably) drawing a reference vac off the engine. How does the ECU have any say in that setup?
The Blitz ECU I've got claims a 30-40% boost increase, so I should have between 0.65 and 1.16 bar. At least two people on the MR2 owners clubs have got the same Blitz ECU I have, both are happy with it.
One of them only installed it last week and says the car is much better as a result (and looking at his other posts I think he knows what he's talking about).
I'm thinking that the pointlessly long actuator hose and the other blanked-off hoses around the engine bay could be evidence that they didn't put it back together right when they removed the Greddy EBC it used to have? (Good use of grammar Al!
) In that case, maybe the ECU isn't connected to the turbo system, causing it to run at the base 0.5 bar and no higher?
I'm guessing; but it's sort-of an educated guess.
I've gone around all of the hoses now and checked thoroughly for boost leaks. I haven't checked the intercooler itself, so I'll do that tonight if I get home in time. None of the other tubes had signs of anything that could cause a blockage, but you never know.
I understand what you're saying about electronic boost controllers, but I'd much rather trace and fix the problem - hence restoring normal power, before I go hunting for extra...
I really need to pick up that boost gauge (the one that works!).
Russ - you aren't kidding about the RR day mate! I'm hoping I'll need one pretty soon to verify she's back to full health.
Then another to see what the EBC does.
Keep the suggestions coming guys! I can't afford to have MR T go at it so I need your support!
Cheers!
Turbo T said:
But it must be bleeding the boost off somewhere no?
Thinking about it - I'd say the options are it's either loosing the boost somewhere or not making it in the first place.
I'm pretty sure that;
*The turbo itself is healthy
*There are no leaks in the pipes
*The wastegate is operating normally
*The car is fuelling pretty well and sparking fine
So either I'm loosing boost;
*via the intercooler
*somewhere else I can't think of
Or it simply isn't trying to boost over 0.5 bar.
The intercooler looks in good condition, and I'm wondering if the consistent figure of 0.5 bar (the base boost it's supposed to generate) is a coincidence.
It's just the way it comes on boost, heads straight to 0.5 bar and then sits there all the way through the rev range that's got me thinking...
This will all be much clearer tomorrow - I've got access to a scanner tonight so I'll be able to post the actual printouts for you guys.
Limp mode was my first thought, but Charlie wasn't convinced.
From what I've read the Blitz is basically a standard ECU, but Blitz insert an extra chip holding revised mappings.
I actually tried the codes, it's showing nothing - and I've covered well over 1,000 miles since the last reset.
>> Edited by _Al_ on Tuesday 4th October 11:48
From what I've read the Blitz is basically a standard ECU, but Blitz insert an extra chip holding revised mappings.
I actually tried the codes, it's showing nothing - and I've covered well over 1,000 miles since the last reset.
>> Edited by _Al_ on Tuesday 4th October 11:48
Al,The MR2OC thread info seems logical sense,esp as you seem to have some blanked off tubing.
All other rubber tubing,try to keep as short & unkinked as poss.Also check that existing tubing is stiff enough.Someone had fitted a short (2"
length off *soggy* tubing to the inlet manif on our car.Anyway, as soon as it was exposed to any decent amount of vacuum it was collapsing & so restricting flow.Took me ages & much head scratching(splinters!
)to work it out & trace.
I guess to be able to monitor, accurately, for vacuum/boost problems you are gonna have to bite the bullet & get a boost gauge tho.(highly reccomend one with memory/warning mode,as it'll yell at you if things are going pear shaped)
All other rubber tubing,try to keep as short & unkinked as poss.Also check that existing tubing is stiff enough.Someone had fitted a short (2"
length off *soggy* tubing to the inlet manif on our car.Anyway, as soon as it was exposed to any decent amount of vacuum it was collapsing & so restricting flow.Took me ages & much head scratching(splinters! )to work it out & trace. I guess to be able to monitor, accurately, for vacuum/boost problems you are gonna have to bite the bullet & get a boost gauge tho.(highly reccomend one with memory/warning mode,as it'll yell at you if things are going pear shaped)
tuttle said:
Al,The MR2OC thread info seems logical sense,esp as you seem to have some blanked off tubing.
All other rubber tubing,try to keep as short & unkinked as poss.Also check that existing tubing is stiff enough.Someone had fitted a short (2"
I guess to be able to monitor, accurately, for vacuum/boost problems you are gonna have to bite the bullet & get a boost gauge tho.(highly reccomend one with memory/warning mode,as it'll yell at you if things are going pear shaped)
is the 'liner operation now T?
my offer of help and the use of my pit still stands if you need a hand
...... Also don't discount the effect of heat soak, to be honest after market filters on MR2T's are often a way to loose power rather than gain.
But that's just an aside, as it seems low boost is the cause of lack of power.
You could try giving Millway a call, they are based in Basingstoke and they know quite a bit about MR2T's.
As Gazboy mentions have you checked over your intercooler?
But that's just an aside, as it seems low boost is the cause of lack of power.
You could try giving Millway a call, they are based in Basingstoke and they know quite a bit about MR2T's.
As Gazboy mentions have you checked over your intercooler?
Turbo T said:
what is the stock wastgate/actuator setting. That should be the minimum the car will boost to.
Is there any way I can check/adjust it?
I'm off home now so it'll be dark by the time I'm back, but I'll have a look round and try these suggestions.
I'm particularly interested in these blanked pipes but the wastegate is a strong second, followed by the intercooler.
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