Discussion
Can anyone fully explain the difference between MAP and Throttle angle..Im aware there are two different ways or two different tunning settings..What are the advantages when deciding which one to use..Mine is currently on throttle angle..Ive heard that MAP is more econmical.I still have the intermittent hot start problem and the only cure is to push the throttle to the floor..is this a easy fix..Is there any one in the East Midlands who knows how to work these things.The other thing which is worrying is i tried to start the car from cold after about 10 seconds there was a large explosion ,the loudest bang ive ever heard..now happened twice..Im wondering if its to much fuel or not enough..Ive not touched anything on the megasquirt..
Edited by SILICONEKID340HP on Sunday 17th July 16:36
Edited by SILICONEKID340HP on Sunday 17th July 16:37
Think about it Daz, TPS only tells the ECU what angle the throttle butterfly is at.
MAP actually tells the ECU what the load on the engine is, the TPS way assumes this.
That is how I see it anyway, I believe MAP can take longer to map with.
Sure someone with far more knowledge will be along to correct me.....
MAP actually tells the ECU what the load on the engine is, the TPS way assumes this.
That is how I see it anyway, I believe MAP can take longer to map with.
Sure someone with far more knowledge will be along to correct me.....
So what are the advantages with MAP?Noticed the EGO correction sticks within 5% from 95% to 105%(hard acceleration) a which is good but on cruise it can be up to 15% each way, does that mean thhe VE table is not close enough to the AFR table or is 15% acceptable..The EGO correction guage turns red at 10% so that must me telling me something..
Edited by SILICONEKID340HP on Sunday 17th July 17:54
Hi Daz,
OK, this isnt an easy subject to explain and Im not particually good at explaining things clearly, but here goes:
I've always sworn by MAP until 2 weeks ago, its certainly more economical, if your decelerating and holding a fixed throttle position then the engine will draw a large vacuum (low KPa value) the ECU will see the lower KPa reading and run less fuel (if mapped to do this). Its also more forgiving for any changes in the intake. It also works better with the idle valve, for example if your valve increases the air coming into the plenum then the MAP will alter, therefore the fueling will alter. If using TPS you end up with a leaner mix as the ECU doesnt see any change.
MAP is much harder to tune, hence why a lot of tuners like to use TPS.
I've always used MAP until I fitted my 5.4 from V8D, I tuned it on MAP and it simply didnt respond as well as other V8D engines. So Shaun and Rob talked me into re-tuning it using TPS and I have to say I'm now converted to this method. Its far more responsive, as the fueling now follows the throttle. Looking through datalogs the TPS alters instantly when you accelerate(as youd expect), but the MAP is a good 50-100mS slower to respond. This means that the fueling is always lagging when you boot it. This causes a large lean HOLE in the fueling when you accelerate. The AFR is also much more constant using TPS than it is using MAP and it was so easy to tune!
Now it accelerates as I expected it to, I hardly need any accel enrichment as the fueling follows my throttle position. OK, I guess its not as economical, but I've never worried about that. I simply want it fueled correctly, if I want an economical drive I'll go out in the MX5.
So MAP is a better method as far as economy is concerned, but TPS is far more responsive.
Phil
OK, this isnt an easy subject to explain and Im not particually good at explaining things clearly, but here goes:
I've always sworn by MAP until 2 weeks ago, its certainly more economical, if your decelerating and holding a fixed throttle position then the engine will draw a large vacuum (low KPa value) the ECU will see the lower KPa reading and run less fuel (if mapped to do this). Its also more forgiving for any changes in the intake. It also works better with the idle valve, for example if your valve increases the air coming into the plenum then the MAP will alter, therefore the fueling will alter. If using TPS you end up with a leaner mix as the ECU doesnt see any change.
MAP is much harder to tune, hence why a lot of tuners like to use TPS.
I've always used MAP until I fitted my 5.4 from V8D, I tuned it on MAP and it simply didnt respond as well as other V8D engines. So Shaun and Rob talked me into re-tuning it using TPS and I have to say I'm now converted to this method. Its far more responsive, as the fueling now follows the throttle. Looking through datalogs the TPS alters instantly when you accelerate(as youd expect), but the MAP is a good 50-100mS slower to respond. This means that the fueling is always lagging when you boot it. This causes a large lean HOLE in the fueling when you accelerate. The AFR is also much more constant using TPS than it is using MAP and it was so easy to tune!
Now it accelerates as I expected it to, I hardly need any accel enrichment as the fueling follows my throttle position. OK, I guess its not as economical, but I've never worried about that. I simply want it fueled correctly, if I want an economical drive I'll go out in the MX5.
So MAP is a better method as far as economy is concerned, but TPS is far more responsive.
Phil
daxtojeiro said:
Hi Daz,
OK, this isnt an easy subject to explain and Im not particually good at explaining things clearly, but here goes:
I've always sworn by MAP until 2 weeks ago, its certainly more economical, if your decelerating and holding a fixed throttle position then the engine will draw a large vacuum (low KPa value) the ECU will see the lower KPa reading and run less fuel (if mapped to do this). Its also more forgiving for any changes in the intake. It also works better with the idle valve, for example if your valve increases the air coming into the plenum then the MAP will alter, therefore the fueling will alter. If using TPS you end up with a leaner mix as the ECU doesnt see any change.
MAP is much harder to tune, hence why a lot of tuners like to use TPS.
I've always used MAP until I fitted my 5.4 from V8D, I tuned it on MAP and it simply didnt respond as well as other V8D engines. So Shaun and Rob talked me into re-tuning it using TPS and I have to say I'm now converted to this method. Its far more responsive, as the fueling now follows the throttle. Looking through datalogs the TPS alters instantly when you accelerate(as youd expect), but the MAP is a good 50-100mS slower to respond. This means that the fueling is always lagging when you boot it. This causes a large lean HOLE in the fueling when you accelerate. The AFR is also much more constant using TPS than it is using MAP and it was so easy to tune!
Now it accelerates as I expected it to, I hardly need any accel enrichment as the fueling follows my throttle position. OK, I guess its not as economical, but I've never worried about that. I simply want it fueled correctly, if I want an economical drive I'll go out in the MX5.
So MAP is a better method as far as economy is concerned, but TPS is far more responsive.
Phil
Would you say 1 or 2 mpg less for normal driving..on TPS and what percentage EGO correction is with in the perameters.Mine goes past 15% on cruise and 5%each way on hard acceleration..i still have the hot start problem then i have to clear it by full throotle..Is there a easy way to reduce the fuel when cranking at the problem temp..OK, this isnt an easy subject to explain and Im not particually good at explaining things clearly, but here goes:
I've always sworn by MAP until 2 weeks ago, its certainly more economical, if your decelerating and holding a fixed throttle position then the engine will draw a large vacuum (low KPa value) the ECU will see the lower KPa reading and run less fuel (if mapped to do this). Its also more forgiving for any changes in the intake. It also works better with the idle valve, for example if your valve increases the air coming into the plenum then the MAP will alter, therefore the fueling will alter. If using TPS you end up with a leaner mix as the ECU doesnt see any change.
MAP is much harder to tune, hence why a lot of tuners like to use TPS.
I've always used MAP until I fitted my 5.4 from V8D, I tuned it on MAP and it simply didnt respond as well as other V8D engines. So Shaun and Rob talked me into re-tuning it using TPS and I have to say I'm now converted to this method. Its far more responsive, as the fueling now follows the throttle. Looking through datalogs the TPS alters instantly when you accelerate(as youd expect), but the MAP is a good 50-100mS slower to respond. This means that the fueling is always lagging when you boot it. This causes a large lean HOLE in the fueling when you accelerate. The AFR is also much more constant using TPS than it is using MAP and it was so easy to tune!
Now it accelerates as I expected it to, I hardly need any accel enrichment as the fueling follows my throttle position. OK, I guess its not as economical, but I've never worried about that. I simply want it fueled correctly, if I want an economical drive I'll go out in the MX5.
So MAP is a better method as far as economy is concerned, but TPS is far more responsive.
Phil
Edited by SILICONEKID340HP on Sunday 17th July 20:53
SILICONEKID340HP said:
daxtojeiro said:
Hi Daz,
OK, this isnt an easy subject to explain and Im not particually good at explaining things clearly, but here goes:
I've always sworn by MAP until 2 weeks ago, its certainly more economical, if your decelerating and holding a fixed throttle position then the engine will draw a large vacuum (low KPa value) the ECU will see the lower KPa reading and run less fuel (if mapped to do this). Its also more forgiving for any changes in the intake. It also works better with the idle valve, for example if your valve increases the air coming into the plenum then the MAP will alter, therefore the fueling will alter. If using TPS you end up with a leaner mix as the ECU doesnt see any change.
MAP is much harder to tune, hence why a lot of tuners like to use TPS.
I've always used MAP until I fitted my 5.4 from V8D, I tuned it on MAP and it simply didnt respond as well as other V8D engines. So Shaun and Rob talked me into re-tuning it using TPS and I have to say I'm now converted to this method. Its far more responsive, as the fueling now follows the throttle. Looking through datalogs the TPS alters instantly when you accelerate(as youd expect), but the MAP is a good 50-100mS slower to respond. This means that the fueling is always lagging when you boot it. This causes a large lean HOLE in the fueling when you accelerate. The AFR is also much more constant using TPS than it is using MAP and it was so easy to tune!
Now it accelerates as I expected it to, I hardly need any accel enrichment as the fueling follows my throttle position. OK, I guess its not as economical, but I've never worried about that. I simply want it fueled correctly, if I want an economical drive I'll go out in the MX5.
So MAP is a better method as far as economy is concerned, but TPS is far more responsive.
Phil
Would you say 1 or 2 mpg less for normal driving..on TPS and what percentage EGO correction is with in the perameters.Mine goes past 15% on cruise and 5%each way on hard acceleration..i still have the hot start problem then i have to clear it by full throotle..Is there a easy way to reduce the fuel when cranking at the problem temp..OK, this isnt an easy subject to explain and Im not particually good at explaining things clearly, but here goes:
I've always sworn by MAP until 2 weeks ago, its certainly more economical, if your decelerating and holding a fixed throttle position then the engine will draw a large vacuum (low KPa value) the ECU will see the lower KPa reading and run less fuel (if mapped to do this). Its also more forgiving for any changes in the intake. It also works better with the idle valve, for example if your valve increases the air coming into the plenum then the MAP will alter, therefore the fueling will alter. If using TPS you end up with a leaner mix as the ECU doesnt see any change.
MAP is much harder to tune, hence why a lot of tuners like to use TPS.
I've always used MAP until I fitted my 5.4 from V8D, I tuned it on MAP and it simply didnt respond as well as other V8D engines. So Shaun and Rob talked me into re-tuning it using TPS and I have to say I'm now converted to this method. Its far more responsive, as the fueling now follows the throttle. Looking through datalogs the TPS alters instantly when you accelerate(as youd expect), but the MAP is a good 50-100mS slower to respond. This means that the fueling is always lagging when you boot it. This causes a large lean HOLE in the fueling when you accelerate. The AFR is also much more constant using TPS than it is using MAP and it was so easy to tune!
Now it accelerates as I expected it to, I hardly need any accel enrichment as the fueling follows my throttle position. OK, I guess its not as economical, but I've never worried about that. I simply want it fueled correctly, if I want an economical drive I'll go out in the MX5.
So MAP is a better method as far as economy is concerned, but TPS is far more responsive.
Phil
Edited by SILICONEKID340HP on Sunday 17th July 20:53
Its not the starter motor ..The problem arises when the engine is at a certain temperature ..I have to push the thottle to the floor which clears it and then it starts.For a while the idle is all over the place and i get a smell of petrol..Its only happening within a small temp range so the way i look at it is to much fuel is going in ..Im not sure how to reduce the amount of fuel..Im not sure if its cranking pulse width or Priming pulse width..i can see the dot on the screen but im not conversant enough to start touching it..The other problem is i had a very loud bang after trying to start it from cold ,this has happened twice..like not enough fuel or to much..like a back fire..
SILICONEKID340HP said:
Its not the starter motor ..The problem arises when the engine is at a certain temperature ..I have to push the thottle to the floor which clears it and then it starts.For a while the idle is all over the place and i get a smell of petrol..Its only happening within a small temp range so the way i look at it is to much fuel is going in ..Im not sure how to reduce the amount of fuel..Im not sure if its cranking pulse width or Priming pulse width..i can see the dot on the screen but im not conversant enough to start touching it..The other problem is i had a very loud bang after trying to start it from cold ,this has happened twice..like not enough fuel or to much..like a back fire..
sounds to me like its over fueling! Putting your foot on the throttle is probably the cause, or are you flooring the throttle with the ignition off just to open the butterfly and clear its throat? the bang is probably unburnt fuel igniting in the exhaust manifoldYour probably right there regarding the bang..You can see with the ignition on the dot moveing up and down the AFR table thats why i suspected it is tuned TPS..
I just need to find out how to put a little less fuel in at the problem temperature.What i could do is wait for it not to start, connect the lap top and then the live dot will be at the problem temp..i can get that far but don`t know how to reduce the fuel slightly..
Im learning slowly but at this point not confident to touch it..Think some one should start a course up to learn how to Tune the megasquirt instaed of it being a long drawn out slog !
Hope the MPG is not effected to much being TPS..
I just need to find out how to put a little less fuel in at the problem temperature.What i could do is wait for it not to start, connect the lap top and then the live dot will be at the problem temp..i can get that far but don`t know how to reduce the fuel slightly..
Im learning slowly but at this point not confident to touch it..Think some one should start a course up to learn how to Tune the megasquirt instaed of it being a long drawn out slog !
Hope the MPG is not effected to much being TPS..
Edited by SILICONEKID340HP on Sunday 17th July 22:18
Darren why don't you learn to save a tune in software on the top right of the page under file "save tune as" name it like "Daz pre cock-up" for example 
then have a play in the start-up/idle tab then if you f
k up you can just reload the saved tune/MSQ you named previously and be back to square one 
get yourself familiar with this before plugging in your ECU & get yourself on the forums http://www.msefi.com/index.php the only way to learn is read always works for me as the spoken word never sunk in for me 
it may look daunting but you will find what you seek + I find reading the other stuff interesting anyways 
we all like reading on PH's that's why were here 
agree with Slideways on the possible overfueling thing though maybe to much "cranking pulse width" 
interesting concerning the throttle angle mapping on your car Phil 
then have a play in the start-up/idle tab then if you fk up you can just reload the saved tune/MSQ you named previously and be back to square one get yourself familiar with this before plugging in your ECU & get yourself on the forums http://www.msefi.com/index.php the only way to learn is read always works for me as the spoken word never sunk in for me it may look daunting but you will find what you seek + I find reading the other stuff interesting anyways we all like reading on PH's that's why were here agree with Slideways on the possible overfueling thing though maybe to much "cranking pulse width" interesting concerning the throttle angle mapping on your car Phil Edited by Simon says on Sunday 17th July 22:58
Darren,
send me your msq file and I will take a look at it. If your having to put your foot to the floor then your triggering flood clear which means it cuts fuel, therefore the ECU is adding far too much fuel or the priming pulse is too high around that temperature.
If you can't figure out how to save the msq file give me a ring and I will talk you through it, I think you have my number but if not give me a shout via email.
cheers,
Phil
send me your msq file and I will take a look at it. If your having to put your foot to the floor then your triggering flood clear which means it cuts fuel, therefore the ECU is adding far too much fuel or the priming pulse is too high around that temperature.
If you can't figure out how to save the msq file give me a ring and I will talk you through it, I think you have my number but if not give me a shout via email.
cheers,
Phil
Alexdaredevilz said:
Is there any one out there who is 100% happy with there mega squirt with out constant mapping tweeks?
It just seems that every one has a idle/overfueling/starting etc etc
To be honest it shouldnt be any difference from any other ECU, as starting is a simple fueling calculation that only looks at coolant temperature, so therefore very easy to tune. It just seems that every one has a idle/overfueling/starting etc etc
Mine starts at all temperatures without any throttle input, I can stand outside the car, turn it over and it just runs,
Phil
I'm also having a bit of a hot start issue with since installing the megasquirt system (fuel Only). Engine cranks over but won't start with no RPM indicated on the rev-counter during cranking. I think this is a different issue to Daz's and probably down to the ECU not picking up the revs from the coil and therefore not putting in any fuel. I'm guessing here but I think this might be caused by a bad connection to the coil or the wiring just behind it.
Also noticed that it seems to take a while for the heat to build up. For instancce yestertday when I stopped to fill up with fuel, the car was parked for <5 minutes and started fine. Later I stopped at a shop for about 15 minutes and it wouldn't start. Opened the bonnet for a about 5 minutes to get some cooler air in and it was fine.
Tried to replicate this once I got home; let it idle for a while to build up temperature and it started up again no problemm. left it for about 15 minutes and came back on it wouldn't start.
Also noticed that it seems to take a while for the heat to build up. For instancce yestertday when I stopped to fill up with fuel, the car was parked for <5 minutes and started fine. Later I stopped at a shop for about 15 minutes and it wouldn't start. Opened the bonnet for a about 5 minutes to get some cooler air in and it was fine.
Tried to replicate this once I got home; let it idle for a while to build up temperature and it started up again no problemm. left it for about 15 minutes and came back on it wouldn't start.
angus99 said:
I'm also having a bit of a hot start issue with since installing the megasquirt system (fuel Only). Engine cranks over but won't start with no RPM indicated on the rev-counter during cranking. I think this is a different issue to Daz's and probably down to the ECU not picking up the revs from the coil and therefore not putting in any fuel. I'm guessing here but I think this might be caused by a bad connection to the coil or the wiring just behind it.
Also noticed that it seems to take a while for the heat to build up. For instancce yestertday when I stopped to fill up with fuel, the car was parked for <5 minutes and started fine. Later I stopped at a shop for about 15 minutes and it wouldn't start. Opened the bonnet for a about 5 minutes to get some cooler air in and it was fine.
Tried to replicate this once I got home; let it idle for a while to build up temperature and it started up again no problemm. left it for about 15 minutes and came back on it wouldn't start.
You may need to move your cranking PW table over to allow for a hotter temp setting so you can fine tune starting if the engine gets saturated with heat. Im guessing you have the last position set to 70 or 80ish, set a few warmer and use these when its saturated. Also ensure you dont have any priming PW once its warm:Also noticed that it seems to take a while for the heat to build up. For instancce yestertday when I stopped to fill up with fuel, the car was parked for <5 minutes and started fine. Later I stopped at a shop for about 15 minutes and it wouldn't start. Opened the bonnet for a about 5 minutes to get some cooler air in and it was fine.
Tried to replicate this once I got home; let it idle for a while to build up temperature and it started up again no problemm. left it for about 15 minutes and came back on it wouldn't start.
Phil
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