AEM Infinity / RIFE 3 Bar Map Sensor

Little stumped with this one so figured I would post up to the group. I have a 454 Big Block running a 250 blower with a AEM infinity 308 running things and a RIFE 3 bar MAP sensor wired up and configured with scaling set up properly. Issue I am having is on quick blips of the throttle the engine would cut out and found it was a boost cut as the MAP was reporting over 18psi which is the boost cut. The blower should not be near 18psi on this engine especially at 2500-3000RPM, should be closer to 10-12psi @6000. Checking the sensor with a hand pressure pump checks out and matches RIFEs calibration data and Infinity sees the same. The MAP also reads OK if I slowly increase throttle. Could this just be a spike in the manifold pressure with the blip of the throttle ? vac line routing ? The MAP is remotely mounted and using a vac line that is plumbed directly into manifold with a T, one line going to map, one line going to FPR. Thanks in advance.

-Nick

Nicholas,

It's possible you're getting a hiccup of combustion coming back into the intake that's causing a valid high intake manifold pressure. Accel enrichment may need tweaked.

The sensor not having a great pressure source may also be the issue, so please send us some pics of where the MAP sensor pressure source is located.Getting it in a large unobstructed plenum area helps avoid dirty signal which MIGHT be a factor here.

Teeing that source into something with a significant diaphragm can present issues, so I wouldn't share it with FPR, bypass valve, etc.

Ill get some pics of the routing tomorrow but it is Td right off the manifold using the stock location that is used for fpr, MAP sensor granted that was with a GM map and stock fpr. I may also just switch over to push lock vac lines with dedicated lines to FPR and MAP.

Sounds good! When you say push lock if you're referring to synthetic rubber hose plus push lock AN fittings great, if you mean the plastic type, just be aware that "hard" lines tend to increase noise since the material itself doesn't damp pulses like rubber does.

I was thinking hard line but good call with the rubber damping some of the pulses. Took a pic of the current vac line in the boat and wasn't too proud of how I left it so I ordered a nice billet vac block and going to run a dedicated line to each the MAP sensor and FPR. But as promised here is a pic of the current set up, it certainly was a use what I had to avoid another trip to the parts store situation :).

Gotcha, also if you're sharing 5v, sensor ground with the fuel pressure sensor I see in the pic, those with that connector are prone to intermittent faults which can impact other sensors, so keep an eye out.