R34 GTT on Haltech ECU No MAP Input

[tsyk3s]

Hello all.

I have recently put a Haltech Platiunum Pro ECU in my R34 GTT but I have 1 problem.

I am not receiving any input from the MAP sensor as it just sits at -1.3 PSI no matter what.

Does anyone know why this is happening?

Do I just have a busted MAP or is there something else going on. 

Any help would be greatly appreciated.

-T3

 

Edit: I have also tried the other MAP inputs in the haltech software but they also don't change anything.

Edited August 11, 2022 by tsyk3s
Clarification

[Duncan]

Can I ask if you have a vacuum/boost source connected to the nipple on the ECU? If so, where is the source?

[tsyk3s]

On 8/11/2022 at 10:39 AM, Duncan said:

Can I ask if you have a vacuum/boost source connected to the nipple on the ECU? If so, where is the source?

No man. I haven't connected a vacuum to the internal sensor, I thought it should be handled via the factory harness. 

Should I connect a vacuum instead? And where would be best?

[Duncan]

Someone more Haltech friendly than me could answer, noting Plat Pro is pretty old software. I believe R34 had a MAP sensor from factory and the Haltech could be configured to use the External Map instead of the Internal/Onboard sensor.

In my R32 the factory MAP was removed long ago (it only runs the boost gauge and doesn't go to ECU), so I had to connect a vacuum source to the internal sensor nipple. The vacuum source has to be after the throttle(s)

[robbo_rb180]

On 8/11/2022 at 10:43 AM, tsyk3s said:

No man. I haven't connected a vacuum to the internal sensor, I thought it should be handled via the factory harness. 

Should I connect a vacuum instead? And where would be best?

You 100% need to connect to the nipple on the haltech. 
Any where after the Throttle body is fine, T off the fuel reg reference.

If you have no experience with ecu setup happy to help if near by


 

Edited August 11, 2022 by robbo_rb180

[GTSBoy]

The R34 does not have a MAP sensor. It does have a sensor (where all previous RBs had none), and it is a MAP sensor, but it is not used by the factory ECU for MAP. It is called the "boost sensor" and it is only really used for effecting what amounts to a boost cut. There is no way that Haltech would have attempted to use it instead of their ECU's on board MAP.

[tsyk3s]

Thabks for all the responses.

So T off the boost sensor should be fine then?

Thanks for all of this again guys

[GTSBoy]

See this thread and my posted images. You have several choices, including the connection for the stock ECU's boost sensor, the BOV, the dash gauge.

 

[joshuaho96]

On 8/10/2022 at 6:17 PM, robbo_rb180 said:

You 100% need to connect to the nipple on the haltech. 
Any where after the Throttle body is fine, T off the fuel reg reference.

If you have no experience with ecu setup happy to help if near by


 

Do not T off the fuel pressure regulator. I hate this practice. With the OEM setup there are two points of failure where the hose can slip and cause a catastrophic lean-out. If you T the hose you have added 4 additional points of failure. If you have to use a boost/vacuum reference, it's best to tee off the same line that the OEM boost gauge runs off of.

[robbo_rb180]

On 8/11/2022 at 2:41 PM, joshuaho96 said:

Do not T off the fuel pressure regulator. I hate this practice. With the OEM setup there are two points of failure where the hose can slip and cause a catastrophic lean-out. If you T the hose you have added 4 additional points of failure. If you have to use a boost/vacuum reference, it's best to tee off the same line that the OEM boost gauge runs off of.

95% of cars its fine and if done correctly with the right sized hose, fittings and a ziptie never have an issue.
 

Edited August 11, 2022 by robbo_rb180

[joshuaho96]

On 8/10/2022 at 9:58 PM, robbo_rb180 said:

95% of cars its fine and if done correctly with the right sized hose, fittings and a ziptie never have an issue.
 

It will work when it works, the problem is what happens when it doesn't work. The failure mode of the FPR hose popping off is bad news if you get into boost. If you tee it off the factory boost gauge instead in most RBs it's just a gauge instead of being used in the ECU. Even in the turbo NEOs the failure mode is not as bad as it would otherwise be, the ECU uses MAFs primarily and the MAP sensor is mostly for transient handling and overboost protection.

[GTSBoy]

On 8/11/2022 at 2:57 PM, joshuaho96 said:

It will work when it works, the problem is what happens when it doesn't work. The failure mode of the FPR hose popping off is bad news if you get into boost. If you tee it off the factory boost gauge instead in most RBs it's just a gauge instead of being used in the ECU. Even in the turbo NEOs the failure mode is not as bad as it would otherwise be, the ECU uses MAFs primarily and the MAP sensor is mostly for transient handling and overboost protection.

That's somewhat of a mixed message or confabulation of two different things.

Point 1. Yes, it is generally a bad idea to tap anything into the FPR connection because when it goes wrong the lean condition is very destructive. No, it doesn't go wrong often, but when it does, it is usually because the ignorance of the failure mode is combined with sufficient general ignorance that the failure becomes more likely through ineptitude. Thus, it is generally easier to simply say "don't do it" than try to have a nuanced discussion.

Point 2. The Neo's boost sensor "failure mode" should you tap into its connection and have that connection fail is not severe at all. But this is where the confabulation occurs, because you made it sound like tapping into the FPR on a Neo was not as bad. There wasn't any need to bring the Neo's boost sensor up as it was lacking in relevance, even with its previous mention in this thread.

/pedant mode.

[joshuaho96]

On 8/11/2022 at 12:18 AM, GTSBoy said:

That's somewhat of a mixed message or confabulation of two different things.

Point 1. Yes, it is generally a bad idea to tap anything into the FPR connection because when it goes wrong the lean condition is very destructive. No, it doesn't go wrong often, but when it does, it is usually because the ignorance of the failure mode is combined with sufficient general ignorance that the failure becomes more likely through ineptitude. Thus, it is generally easier to simply say "don't do it" than try to have a nuanced discussion.

Point 2. The Neo's boost sensor "failure mode" should you tap into its connection and have that connection fail is not severe at all. But this is where the confabulation occurs, because you made it sound like tapping into the FPR on a Neo was not as bad. There wasn't any need to bring the Neo's boost sensor up as it was lacking in relevance, even with its previous mention in this thread.

/pedant mode.

Yeah it was a little confusing as stream of consciousness. To be clear I’m referring to a failure in a NEO turbo where you have another MAP sensor or something similar teed with the OEM MAP sensor for whatever reason. 

[kevboost7]

I have a question, lets say hypothetically, i tried driving the car without a vacuum source/hose connected to the haltech internal map sensor. What is happening to the internals of the car?

I'm asking that because i did the same thing and tried to go for a 20 minute drive to mess with the tuning software and i could never rev past 4000 rpm. 

I switched the haltech ecu back to the factory ecu until i take the car to a dyno/tuner, but i lay in bed at night wondering if i caused any damage by doing that. 

[GTSBoy]

So, you disconnected the primary load sensor from the Haltech, and wonder why it doesn't work nice? You better not have put too much load on the engine. Could have been pinging its tits off.

[kevboost7]

1 hour ago, GTSBoy said:

So, you disconnected the primary load sensor from the Haltech, and wonder why it doesn't work nice? You better not have put too much load on the engine. Could have been pinging its tits off.

what does pinging its tits off mean

[Duncan]

Well, if the MAP is disconnected from the intake, the ECU will think it is getting exactly atmospheric pressure....no vacuum with open throttle off boost and no extra air on boost.

so yeah, it can probably idle and run OK at light throttle/low revs. But beyond that if you are pulling say 15psi vacuum (I know that is not valid BTW) at 2000 rpm with throttle wide open it will be running mega rich and might foul plugs, missfire or stall because it is getting way less air than it thinks. Conversely, if you manage to get it onto boost somehow it will be getting way more air than it knows and this is a big problem, like GTSBoy said you could ping it to death.

BTW, air flow meter cars are the same to some extent. An unplugged AFM will probably allow a car to start and idle but anything more than than very light throttle it will have too much air compared to ECU expectation and stall

[Murray_Calavera]

7 hours ago, kevboost7 said:

I have a question, lets say hypothetically, i tried driving the car without a vacuum source/hose connected to the haltech internal map sensor. What is happening to the internals of the car?

I'm asking that because i did the same thing and tried to go for a 20 minute drive to mess with the tuning software and i could never rev past 4000 rpm. 

I switched the haltech ecu back to the factory ecu until i take the car to a dyno/tuner, but i lay in bed at night wondering if i caused any damage by doing that. 

I have some bad news for you. What you experienced is a severe lean misfire. I imagine it felt like you were hitting the engine rev limiter. 

The reason why you couldn't increase the RPM further, is because at 4000 RPM, the mixture was so lean it was unable to ignite. An engine can still "run" while very lean, but to experience what happened to you, your mixture at that point would have been leaner then 19 AFR.

When an engine leans out, it is highly susceptible to detonation/pinging and is the quickest way to kill your engine. 

If you are worried, have your mechanic put a bore scope in the cylinders and check the tops of the pistons for pitting. But at the end of the day, if it still runs, just forget it ever happened and move on. 

[kevboost7]

20 hours ago, Murray_Calavera said:

I have some bad news for you. What you experienced is a severe lean misfire. I imagine it felt like you were hitting the engine rev limiter. 

The reason why you couldn't increase the RPM further, is because at 4000 RPM, the mixture was so lean it was unable to ignite. An engine can still "run" while very lean, but to experience what happened to you, your mixture at that point would have been leaner then 19 AFR.

When an engine leans out, it is highly susceptible to detonation/pinging and is the quickest way to kill your engine. 

If you are worried, have your mechanic put a bore scope in the cylinders and check the tops of the pistons for pitting. But at the end of the day, if it still runs, just forget it ever happened and move on. 

Thanks for the answer, although now i wish i never asked... this is one of those situations where ignorance is bliss.

 

But yes, that is exactly what was happening, it felt like a rev limiter. 

[joshuaho96]

On 12/9/2022 at 10:19 AM, kevboost7 said:

Thanks for the answer, although now i wish i never asked... this is one of those situations where ignorance is bliss.

 

But yes, that is exactly what was happening, it felt like a rev limiter. 

It’s probably fine unless you actively tried to get it deep into boost and hold it just short of where it started misfiring. The danger is when you get deep into boost and it’s rich enough to ignite reliably but lean enough to get dangerously hot and knock-happy. If you just floored it and let it sit at the misfire limit you probably didn’t blow up your engine. The stock Haltech base map has even less timing than the stock ECU tune.