PMAS intake w/tune stalling on warm start

[NGOT8R]

Someone correct me if I’m wrong, but is PMAS saying that their MAF sensor for the GT350 is supposed to replicate the factory MAF sensor when used with the factory GT350 air box? If so, I’m even more confused because if that‘s the case, why did my GT350 PMAS air intake kit come with the revised metal filter shroud/partial air box? Aside from that, I don’t think the PMAS would work with the factory GT350 air box without some sort of hack job. I would think that if the PMAS was supplied with the revised metal filter shroud/partial air box, their MAF sensor would be tuned for that specific setup. Nowhere in my instructions does it say to reuse the factory air box.

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[GregO]

Time for a phone call to sort this out ?

 

[NGOT8R]

Time for a phone call to sort this out ?

I actually don’t think that will do me any good. It sounds like PMAS is suggesting to install my factory MAF sensor, get the MAF data from their website and forward it to my tuner for a revision to avoid a possible mismatch (huh?)...SMH. I’m still in my free revision period, so I may ask Lund to update my tunes, just as they would a tune required PMAS air intake kit. I want to drive the car for at least 50 miles before doing anything though. I just filled up a few days ago with pump ethanol and transitioned to my Flex tune and I didn’t drive the car long enough to let it learn the new alcohol content yet. When I started it last to move it around at the house, it stumbled like it usually does when I fill up, but quickly recovered like it always does.

The weather has been rainy for the past three days and I just washed and waxed the car, so I need a break in the weather before I can get back out there.

 

[v8hgt]

I occasionally experience something similar with my gt350 im and TB combination on my 2017 GT (aed tune).
It only seems to occur if I am stuck in stop start traffic jams, then stop to fill up with fuel. Then on restarting it can occasionally suffer a stall. I suspect it’s being caused by heat soak. If I don’t shut the engine off it behaves perfectly in stop start traffic. If I stop for fuel in normal conditions with normal air flow then the restarting is fine.

There is one shell fuel station on the way out of Liverpool city centre which always gives me this problem in rush hour where the traffic is moving between 0-10 mph max for 30 mins of my life every day!

 

[NGOT8R]

I occasionally experience something similar with my gt350 im and TB combination on my 2017 GT (aed tune).
It only seems to occur if I am stuck in stop start traffic jams, then stop to fill up with fuel. Then on restarting it can occasionally suffer a stall. I suspect it’s being caused by heat soak. If I don’t shut the engine off it behaves perfectly in stop start traffic. If I stop for fuel in normal conditions with normal air flow then the restarting is fine.

There is one shell fuel station on the way out of Liverpool city centre which always gives me this problem in rush hour where the traffic is moving between 0-10 mph max for 30 mins of my life every day!

Are you also running the factory GT350 CAI kit with a factory MAF sensor, or another brand CAI?

 

[v8hgt]

Are you also running the factory GT350 CAI kit with a factory MAF sensor, or another brand CAI?

I’m using factory gt350 CAI and TB but stock GT MAF and steeda air filter. All Ford parts except the air filter and the AED tune. As I sat under all other circumstances it’s perfect and drives like a factory set up.

 

[NGOT8R]

I’m using factory gt350 CAI and TB but stock GT MAF and steeda air filter. All Ford parts except the air filter and the AED tune. As I sat under all other circumstances it’s perfect and drives like a factory set up.

Oh ok. Do you know if your tuner had to make changes to the MAF Transfer Function Table in your tune?

 

[WildHorse]

Oh ok. Do you know if your tuner had to make changes to the MAF Transfer Function Table in your tune?

Yep you need a slight revision too airflow vs voltage & MAF airflow vs Period cause his is a 15-17 with a smaller MAF housing as compared to the GT350 housing.

 

[kluke15]

i had some warm start issues on my 17 with the pmas no tune required on. put on mishimoto tube and never had the same issue. i also felt like the pmas had some drivability issues or was just way too touchy for my liking. drives much better with the mishi tube.

 

[NGOT8R]

Yep you need a slight revision too airflow vs voltage & MAF airflow vs Period cause his is a 15-17 with a smaller MAF housing as compared to the GT350 housing.

This might sound a little crazy, but I was just going through some old photos of when I was programming my ProMax nitrous controller. In the beginning, when I first powered up the ProMax, my TPS reading was at 26%. Needless to say, I adjusted the voltage to where it was reading 0% at closed throttle and 100% at WOT before the first drive and the idle has been hanging ever since. I wonder if this could have i diced the ha going idle? Should I try going back to the original voltage setting to see if that clears it up? Just trying to backtrack and see where I might have gone off-road here.

 

[K4fxd]

I reached out to Lund regarding this issue, I was told the issue is not tune related.

I can't count how many times I've heard this.

Unfortunatly without looking at the tune and logs there is no way to know.

 

[NGOT8R]

I can't count how many times I've heard this.

Unfortunatly without looking at the tune and logs there is no way to know.

When my tuner told me this, my first thought was that they had tried numerous times in the past and had exhausted all of their means to correct this issue, therefore gave the response that I posted. I wish they had done what you said and looked at the logs or had me do an idle, step rev and a slow climb though. Maybe there would have been something that stood out to him.

 

[GregO]

, when I first powered up the ProMax, my TPS reading was at 26%. Needless to say, I adjusted the voltage to where it was reading 0% at closed throttle and 100% at WOT

As a laymen that deals with 4-20mA signals used for flowcontrol valves, mass flowmeters, pressure transmitters etc. 0% = 4mA.
0% doesn’t = 0mA. Where as 100% open = 20mA unless of course I’m dealing with falling rate vs rising rate.

Off the cuff, the TPS @ idle shouldn’t read 0%.

Your reading of 26% is possibly the throttle blade home position which is typically 30 deg from full closed.
Keep in mind you have the 87mm General Motors S-style TB. The blade position angles at low speeds require more blade opening than a straight bore TB such as the FoMoCo 80mm

 

[K4fxd]

My throttle reads 10% at 650 RPM idle.

 

[NGOT8R]

My throttle reads 10% at 650 RPM idle.

Gotcha! What does it read at WOT (somewhere in the 90+% range)?

As a laymen that deals with 4-20mA signals used for flowcontrol valves, mass flowmeters, pressure transmitters etc. 0% = 4mA.
0% doesn’t = 0mA. Where as 100% open = 20mA unless of course I’m dealing with falling rate vs rising rate.

Off the cuff, the TPS @ idle shouldn’t read 0%.

Your reading of 26% is possibly the throttle blade home position which is typically 30 deg from full closed.
Keep in mind you have the 87mm General Motors S-style TB. The blade position angles at low speeds require more blade opening than a straight bore TB such as the FoMoCo 80mm

Thanks for posting the throttle chart; it’s very helpful. I’m going to adjust my throttle blade opening to see if that improves the condition. It’s super easy to adjust the voltage. I can see the actual position in real time. I’ll start at 10% and work my way back up to 26% where it was before I made any adjustments and see what happens.

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