MAP clamp, can I still effectively tune via load?

[plasticknives]

I recently installed the E-Manage into my 96 Civic DX along with the GReddy 15g turbo kit (5.5psi stock). I am going to need to clamp the MAP voltage at 2.9 (2.93 is 0vac). My question is can I still effectively tune above 2.9 volts via the 'pressure sensor (v) x RPM' rather than 'throttle % x RPM'?

Also, I was planning on using the greddy pretuned map on my d16y7 (the map is for a 92-95 d16z6). The car pulls fine during partial throttle with mid 12 a/f according to my wideband. However, when I go WOT, the a/f instantly pegs 10 a/f (probably lower), regardless of RPM or load, and the car bogs down.

I downloaded the stock 15g civic map from the emanage yahoo group, and it has the boost clamp at 3.00. I am not entirely sure, but is the throttle position directly related to the MAP voltage? If this is true, I would think this would be the reason for the car to go into a sort of 'limp mode' at higher throttle points.

I should also mention I am using the the EX 240cc injectors instead of my DX 190cc injectors. The car idles well at stoich, is it still necessary to input the correction factor?


I don't have the support cable yet, just ordered one from giff-tech. Wish I knew this site before I bought it, could have saved 5 bucks!

Thanks.
Brian

[Dzaster]

You have the Emanage Blue? Do you also have the Greddy MAP sensor? You'll definitely want the Greddy MAP sensor if you are clamping your stock map. And generally you want to clamp you stock map before it goes to 0 vac so it's operating correctly all the way until clamped. There is a thread about clamping HERE (http://www.diytuning.com/forums/showthread.php?t=72). However, I would not be tuning with that pressure sensor once its clamped. ONce clamped you should be tuning with Greddy MAP sensor.

The flooding you are experiencing is you ECU going into "Open Loop"--from reading off sensors to a preprogrammed map within your ECU that is tailored to have you run rich and thus safe. Going from "close loop" to "open loop" is based off of throttle position not RPM or MAP. However, if your map sensor is not clamped before it is allowed to send a gnarly voltage reading to the ECU(boost), the ECU goes into limp mode. This usually puts you rich and in some cars throws a CEL.

As for the Injector Correction. When you input that values it makes the correction across the board regarding fueling. You get stoich AFR's at idle prolly because, if you are runnning a narrowband O2 signal to teh ECU still, the ECU is correcting fuel to the ECU's pre-programmed target of stoich. However, you should use teh correction factor. I don't think it'll lean you out at idle or cruise (closed loop). It might change things for you in open loop Perhaps not be so rich. Give the injector correction a try but just go easy and watch that wideband(AFR's).

[plasticknives]

I'm not entirely sure about the clamp, this is just what I saw from the map on the yahoo group (which I'm not entirely trusting to be the real locked 15g kit map). I know for obd2a Civics, the clamp is 2.93, but I'm not sure what it is for obd1 Civics.

So what you're saying is, since I haven't corrected the injectors yet, the ecu is still giving the same pulse width to the 240s as it would with the 180s, right? Which would cause my richness. Do you think the 25% increased uncorrected injector size is enough to cause the extremely rich bogging? It does make a lot of sense. 25% on top of the increased injector duty from the emanage could very well be the culprit.

I won't know anything until my cable arrives, but thats going to be the first place I look!

Thanks for your help.

[Dzaster]

I'm not entirely sure about the clamp, this is just what I saw from the map on the yahoo group (which I'm not entirely trusting to be the real locked 15g kit map). I know for obd2a Civics, the clamp is 2.93, but I'm not sure what it is for obd1 Civics.

So what you're saying is, since I haven't corrected the injectors yet, the ecu is still giving the same pulse width to the 240s as it would with the 180s, right? Which would cause my richness. Do you think the 25% increased uncorrected injector size is enough to cause the extremely rich bogging? It does make a lot of sense. 25% on top of the increased injector duty from the emanage could very well be the culprit.

I won't know anything until my cable arrives, but thats going to be the first place I look!

Thanks for your help.
Map clamp, is really just holding voltage so the ECU is thinking this much air is coming in so it will flow this much fuel. So if its a steady voltage then the fuel being disperesed by the ECU is pretty much fixed until you add/trim with the Emanage or until it just goes open-loop(rich).

And for sure, 25% is plenty over fueling especially when it is WOT and overfueling even more. So the open loop richness is compounded with the unfixec injector correction differences.

Unless I missed it, I don't think you mentioned if you have the Greddy MAP sensor, or modified GM MAP sensor installed. Do you?

[plasticknives]

No I am not running any aftermarket MAP sensor. Just the emanage with injector wires. I am planning on using the d16z6 fuel map which should be pretty close for my y7. I don't think I will have to do much finetuning, if at all considering the greddy pretunes are pretty conservative. I think all I need to do is scale back the injectors to get it to run properly.

[Dzaster]

So your stock map sensor is made for boost. IMO, if the MAP ain't meant for boost reading then its best to go with the Greddy or GM MAP sensor. Sounds like you got it though.

[plasticknives]

You know I'm not sure anymore. I'm reading that the stock MAP sensor can handle 1.75 bar absolute pressure (so around 11psi). But I'm also reading that boost cut is at 2.93 volts for obd2 cars, and 3 volts for obd1 cars, which is just about 0 vac. So these two things contradict themselves. I'm going to need to do some further research.

[CG10DET]

you will need to clamp the voltage, but then use the additional injection map based on MAF voltage, as the e-manage SHOULD still see the input voltage.

Going into open loop isn't "directly" related to throttle position, it's actually based on Transient Load, which is a combination of MAF and TPS.

[plasticknives]

So from what I am reading, the stock sensor can handle up to 11psi, but the ecu doesn't have a fuel table for it.

Now the fuel map in the emanage has values for 2.00-5.00 volts for the stock sensor (pressure sensor (V))

With a conversion chart for the stock sensor
2.00v = -8.8in/hg
2.87v = 0
4.01v = 5.8 psi
4.87v = 10.1 psi

The 15g kit is set to 5.5psi at the actuator. Does this mean that between 4.00v and 5.00v, the emanage fuel table is unused?

[Dzaster]

It is if you have values in the fuel table to be used.

[plasticknives]

so theoretically, if I upgrade my injectors to 450s (to handle more boost) and scale them back, I should have a decent basetune already for 10psi.

[Dzaster]

Sure. The main thing is that the MAP is reading boost effectively/accurately. If so, you can tune for sure. But, the Blue is limited in that it is not meant to run such large injectors. I had 440cc and was originally 185cc. It was hard to scale them back while off boost and idle. It ran a bit rich. I also got a surging idle and lots of popping out the exhaust from being so rich when letting off the throttle.

What are your duty cycles now? You might just go for something not quite so overkill. I went with 330cc from a Mazda GTX. All the problems went with the 440cc injectors.

[CG10DET]

I think the realistic limit is a 50% increase in injector size.

[Accord2nrz]

(Take your factory injector size / 2) + factory injector size = maximum allowable injector size for optimal emb usage

[plasticknives]

I guess if I'm going to up the boost I'll have to convert to OBD1 and run a chipped ecu.

Technically couldn't you correct AND scale back the airflow quite a bit, then retard the timing a lot to compensate?

[Dzaster]

You can do some scaling back in the airflow map, but should do so only to the off-boost mapping.

[plasticknives]

So I received my cable today and scaled the injectors from 190 to 240 and that didn't really help the problem. The car still has problems at WOT and hesitates for a while at 5000ish rpm. I was sure that was the problem but it doesn't seem to be.

[Dzaster]

Another member was having a very similar issue at around the same RPM. Once he clamped his stock MAP sensor voltage(@ 3.6v) he was good to boost above and beyond.

[plasticknives]

I was just testing some things and I may be making some progress to this issue.

I ended up zeroing out the entire fuel map and then from 50%-100% throttle, I added 10 for up to 3k, 3-5k i added 20, and 5-7k I added 40 and the car acts like it is supposed to. The A/F's are still really rich, but the car pulls without any hesistation or bucking (so I'm guessing the a/f is right around 10 now, not under 10 like it was before).

With such low correction numbers, this leads me to believe that even though I inputted the injector correction (190 > 240), my injectors still aren't being corrected. Even If I left the entire map zeroed out, I would still get rich A/F's (which makes no sense considering the stock ecu has NO fuel map for boost).

[Dzaster]

Are those injectors high or low impedence? if low, than maybe you need to get some resistors inline.

[plasticknives]

They're high imp. They came out of a 2000 Civic EX. I just talked to greddy and they said to have the injectors tested to see if they're stuck open. It makes sense except the car runs perfect in closed loop. If they were stuck open, I would think even the o2 sensor wouldn't be able to correct for that.

[plasticknives]

I installed my 190cc injectors back and the car still has really low a/f at WOT, but, it pulls hard. the A/f at WOT is 10, but now I know it's actually around 10 since in the upper rpm's it rises to around 10.8. With these injectors, I should be running lean. Partial throttle is lean, but I can up the % on that.


total injector duty cycle is at 100% and normal injector duty cycle is at 80% at 6500rpm.

I've messed around with the 80-100% throttle values and it doesn't seem to change much. It's almost as if my duty cycle is stuck at 100% at WOT. I had the table set at 10 to 40 depending on RPM, which with the stock 190cc's, the car should run extremely lean, but I'm still getting 100% duty.

[CG10DET]

Are the injectors from the same manufacturers? It may be caused by injector latency?

[Accord2nrz]

If an injector is failing it can actually get stuck open this would send a signal to your EMB showing 100% meaning its stuck. That's why a lower injector would show up as super rich.

This typically happens when injectors get overloaded. They either don't flow or flow all the time 100%

Hope this helps.

[plasticknives]

Ok how about this.

The only thing the emanage is doing is boost cut at 3.00v and injectors scaled from 180 to 240 (fuel is zeroed out)

6000rpm, 100% throttle, 73% duty cycle, 11.5-12 a/f

Shouldn't the car run lean as hell with no fuel map?

[Dzaster]

It should. You said like 10psi you were boosting right? f so, then that certainly requires additional fueling.

[plasticknives]

It should. You said like 10psi you were boosting right? f so, then that certainly requires additional fueling.

no no, it's only 6psi.

Someone on another forum said this, tell me if it makes sense to you.

Since the stock honda ecu doesn't have any fuel map for boost, once the car enters boost, it goes back to the original pulse width and duty cycle for the 180s.

From my understanding, the injector scaling is only for the stock ecu fuel map.

If this is true, then I will need to manually scale back my boost settings via the airflow map by -25% since the emanages built in scaling is only for the stock ecu map?

[Accord2nrz]

It makes some sense but No.

the emanage is altering the signal in no way reverts to an original map. since your injectors 240 are scaled for OEM they act as if they were factory. This gives you a good idle. The best way to see this is to look at you inj duty cycles.

Your new injectors are not having to work as hard becuase they're bigger than ur OEM's

when you hit boost cut at 3v the map is still sending the signal but the ecu is only seeing 3v. At some point you should lean out only momentarily.

When you hit boost on a honda ecu it throws into open loop. this means it refers to a fuel table built into the ecu that does not adjust it just an influx of fuel. Since your injectors are larger it will push more fuel in open loop than the factory injectors.

The result is severe richness 10.0 and lower when you hit boost and it can cause the car to shutter and bog down because you're flooding the firing chamber.

Hope this helps more ;)

[plasticknives]

When you hit boost on a honda ecu it throws into open loop. this means it refers to a fuel table built into the ecu that does not adjust it just an influx of fuel. Since your injectors are larger it will push more fuel in open loop than the factory injectors.

The result is severe richness 10.0 and lower when you hit boost and it can cause the car to shutter and bog down because you're flooding the firing chamber.

But since the injectors are scaled back, shouldn't the open loop map be scaled back as well, allowing for the emanage fuel map designed for 240s to be used properly?

[Accord2nrz]

No becuase in open loop the table is based on RPM. its like this.

In closed loop mode
adjust fuel based on map sensor input. example: 3v = spit this much fuel in.

In open loop mode:
For RPM = x% of injector duty cycle.

this means that for any given rpm the injectors are pushing that percentage of duty cycle.

In the case of your injectors the emb knows the difference between 20% of the oem injector and 20% of you new injectors. the ecu is calling for 20% of injectors period. So it is pushing 20% of the new injectors. Which in fuel flow terms is significantly more than the old injectors. That causes you to flow super rich in open loop.

[plasticknives]

No becuase in open loop the table is based on RPM. its like this.

In closed loop mode
adjust fuel based on map sensor input. example: 3v = spit this much fuel in.

In open loop mode:
For RPM = x% of injector duty cycle.

this means that for any given rpm the injectors are pushing that percentage of duty cycle.

In the case of your injectors the emb knows the difference between 20% of the oem injector and 20% of you new injectors. the ecu is calling for 20% of injectors period. So it is pushing 20% of the new injectors. Which in fuel flow terms is significantly more than the old injectors. That causes you to flow super rich in open loop.

So from my understanding, if my MAP is clamped at 3v, anything above vacuum (3v and more) will not be corrected via the injector correction because the injector correction is done by reducing map voltage

So really I need to subtract roughly -25 (180 to 240cc is a 25% jump) from the airflow MAP from around 70% throttle to 100% (WOT range).

This will have effect on my timing though, so I would be better off lowering the fuel map parameters so I don't have to subtract as much from the airflow, right?

Is there any conversion that can be made to determine how much timing is advanced per % of airflow taken away? I don't have access to a dyno so checking the timing while the car is in open loop isn't quite feasible.

[Accord2nrz]

So from my understanding, if my MAP is clamped at 3v, anything above vacuum (3v and more) will not be corrected via the injector correction because the injector correction is done by reducing map voltage

So really I need to subtract roughly -25 (180 to 240cc is a 25% jump) from the airflow MAP from around 70% throttle to 100% (WOT range).

This will have effect on my timing though, so I would be better off lowering the fuel map parameters so I don't have to subtract as much from the airflow, right?

Is there any conversion that can be made to determine how much timing is advanced per % of airflow taken away? I don't have access to a dyno so checking the timing while the car is in open loop isn't quite feasible.

If you mean you initial correction via the parameter settings no. That correction applies across the board regardless of what your emb is sending to the ecu. Now, if you mean once you peg out at boost cut. Then also no. What happens is when your map hits 3v. then even if it goes higher then your EMB will continue to send 3v to the OEM ECU no matter how much higher your boost pushes.

depending on the type of MAP you have it should overload. (5v) right at 0atmosphere. The moment you go into positive pressure(boost). When that happens your car should be going into open loop if it isn't already. For most older hondas this happens at 80% engine load. If your car is an auto this happens in D3 right about 4k rpm at 50% throttle.

If your car is going super rich I reccomending zeroing out your airflow map. and your injector map. Set your boost cut to 2V. this should (on a normal setup) cause you to run majorly lean and should happen before you go into boost.

If your car is OBD2 you have a fight on your hands becuase you consistently dealing with the closed loop mode. The solution to this is to purchase an o2 sensor adapter and wire it into the vtec crossover point. This way you can trigger open loop and tune from whatever rpm you desire(normally when your car goes into boost...around 3k is the norm depending on the size of turbine.)

Your other solution is to take the signal wire from the o2 sensor and wire it into a switch. this way you can switch it off and on whenever you want. Most OEM ECUs don't like it but it does work.

Back on subject. Judging from what you've said at 70% throttle your really giving the motor some juice anyhow so you're likely into open loop when it happens causing you to go rich. Stick the zeroing out plan and set your map for 2v and try tuning from there in closed loop first. then push it til open loop. with everything zeroed out you should find that your slightly right but close to being right on the money.

The general rule of thumb for timing is 1.2 degrees or 2 degrees for every 1lb. of boost.

hope this helps ;)

[plasticknives]

By "switching" the o2 sensor off, wouldn't that make the car go into limp mode, or would it just cause the car to run open loop all the time?

Also, by setting the clamp at 2v, the ECU will only provide as much fuel on its own as 2v allows? So even when the map sensor is reading 4v @ 6000rpm, the oem ecu is only giving fuel for 2v @ 6000rpm?

[Accord2nrz]

It depends on the car but on most honda ecus i have seen it runs in open loop without throwing a code. Mine does not throw a code.

In response to your second question i forgot to ask you if you have a secondary map sensor installed on your system. greddy pressure sensor or GM 3 Bar map conversion?

If dont have either then clamp your map at 4.9v. From there you will have no other means then reducing fuel via the airflow unless you want to set it for 2v and tune up from there. It's much easier to add fuel than it is to take it away with the emb.

[Accord2nrz]

And in case you were wondering, yes carblitz from the e-manage mailing list is right on the heated wire part.
<O:p
Since your o2 sensor is a 4 or 3 wire heated you're only stopping the signal flow to the ecu. Not the power input this is what keeps you from throwing a code. <O:p

[plasticknives]

Ill have to try the o2 wiring. For the time being, I just have it unplugged.

The oem map sensor can handle up to 10psi, so 5v is not 0 vac, 0 vac is around 2.9v. The stock ecu doesn't have any values past 2.9v, so in an NA situation, the map sensor is only being used from 0-2.9v.

My question is, for everything in boost, is the stock ecu just giving the values from 2.9v (providing the clamp is at 2.9)

If I hypothetically set the clamp at lets say 1v, everything from 1v onward will only get the timing and fuel values of 1v (lean and advanced timing)?

[plasticknives]

Here's a visual example of my question:

http://img21.imageshack.us/img21/6851/maphzv.gif


In this picture, the clamp is set at 2.9v
Everything in green is pre 2.9v and everything in red is post 2.9v.

Is everything in red given the values in yellow (2.9v)?

[Accord2nrz]

Ill have to try the o2 wiring. For the time being, I just have it unplugged.

The oem map sensor can handle up to 10psi, so 5v is not 0 vac, 0 vac is around 2.9v. The stock ecu doesn't have any values past 2.9v, so in an NA situation, the map sensor is only being used from 0-2.9v.

My question is, for everything in boost, is the stock ecu just giving the values from 2.9v (providing the clamp is at 2.9)

If I hypothetically set the clamp at lets say 1v, everything from 1v onward will only get the timing and fuel values of 1v (lean and advanced timing)?

The OEM map sensor does in fact handle up to 10PSI. BUT that includes normal atmosphere. The pressure of normal atmosphere at 14.7PSI. That is what is meant by handling 10psi. I had trouble grasping that myself. I had to actually call honda corporate and talk to them on that one.

[plasticknives]

The OEM map sensor does in fact handle up to 10PSI. BUT that includes normal atmosphere. The pressure of normal atmosphere at 14.7PSI. That is what is meant by handling 10psi. I had trouble grasping that myself. I had to actually call honda corporate and talk to them on that one.

You're mistaken ;)

The map sensor is a 1.7bar map sensor, so that 10psi includes the 14.7PSI of absolute pressure PLUS another .7 bar.

[CG10DET]

The OEM map sensor does in fact handle up to 10PSI. BUT that includes normal atmosphere. The pressure of normal atmosphere at 14.7PSI. That is what is meant by handling 10psi. I had trouble grasping that myself. I had to actually call honda corporate and talk to them on that one.

So if it can only handle 10psi, what does it do att full load?

[Accord2nrz]

I Don't know about yours, but mine goes into boost, runs lean and then after that the car will begin to shutter because the map signal is jacked up after that point. Then the only way to resolve it is to shut the car off and restart it.
Don't know about what kind of map sensor you have but every 10PSI OEM Honda map sensor i have read up on does this when you've gone into boost once. <O:p></O:p>
<O:p</O:p

::shrugs::<O:p</O:p
<O:p</O:p

I'm just going off of personal experience and what I’ve have seen Hondas do with my own eyes. <O:p></O:p>
<O:p</O:p

Can I be mistaken? Sure, but like i said before the advice I have been giving you is merely based on what I have experimented with across 4 or 5 different engine models all OBD 2 from the 4th era being 93 - 97.

In answer to your graph though, yes everything after 2.9V will push that value to the ecu. It's why many of us get a second MAP sensor, the emanage then reads the true boost value from that map sensor.

[Dzaster]

Here's a visual example of my question:

http://img21.imageshack.us/img21/6851/maphzv.gif


In this picture, the clamp is set at 2.9v
Everything in green is pre 2.9v and everything in red is post 2.9v.

Is everything in red given the values in yellow (2.9v)?
The output should be 2.9v, yes.

[plasticknives]

Yes the stock ECU can't handle more than 0 vac/2.9v and throws a code, BUT the MAP sensor can handle 10psi of relative pressure. So even if the ecu is clamped at 0 vac, the emanage can still read the full 5volts of the MAP sensor, it just reports 2.9v max to the ecu. So I can still tune off the oem map sensor.

[CG10DET]

I Don't know about yours, but mine goes into boost, runs lean and then after that the car will begin to shutter because the map signal is jacked up after that point. Then the only way to resolve it is to shut the car off and restart it.
Don't know about what kind of map sensor you have but every 10PSI OEM Honda map sensor i have read up on does this when you've gone into boost once. <O:p></O:p>
<O:p</O:p

::shrugs::<O:p</O:p
<O:p</O:p

I'm just going off of personal experience and what I’ve have seen Hondas do with my own eyes. <O:p></O:p>
<O:p</O:p

Can I be mistaken? Sure, but like i said before the advice I have been giving you is merely based on what I have experimented with across 4 or 5 different engine models all OBD 2 from the 4th era being 93 - 97.

In answer to your graph though, yes everything after 2.9V will push that value to the ecu. It's why many of us get a second MAP sensor, the emanage then reads the true boost value from that map sensor.


What I mean though, is if they only read to 10psi then even an a Naturally Aspirated car you will get atmospheric pressure(14.7psi) at full throttle, surely the stock sensor will read up to this?

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