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I got a CEL with DTC 3 Map Sensor Circuit problem.
The last time I got this, I found the connector to the Fuel Enrichment relay was bad, so I replaced it with a soldered joint. This time, the connection seems to be okay but I've been getting a stuttering engine at low speeds (< 5 mph) or accelerating slowly from a stop. It stalled once when trying to accelerate hard out from a low speed.

I suspect the Fuel Enrichment Relay has gone bad but I don't know how to troubleshoot it. Any one know what tests I can subject it to in order to verify its operation? I've considered getting the MAP controller to replace it but I don't think if it will fit under my Neuspeed Strut bar since the sensor connector is already tight under the bar.

BTW, I'm running a D16Y8 with the stock 6psi boost, Walbro fuel pump, and Cartech FMU. I've been running this setup for almost 2 years now.

On another note. I don't konw if my fuel pump is going because I hear a lot of vibration from the tank and pump when the tank it's less than half full, and especially when under braking. Anyone have any experience with their pump going bad?
 

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I would suggest getting the Map Controller. I would trust solid-state devices for reliability way before a relay and a switch. I have been working with military spec electronics for years and I have lots of experience with flakey switches and relays. However, I am not sure what is causing your problem. Just some food for thought. Good luck.

Edit: You could try jumping the contacts on the Boost Pressure Switch and listen for the audible click of the relay engaging. I am not sure when the circuit has power but the key may need to be in the ON position...or it may need to be running. I am not sure.
 

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johnlude85 said:
most of the time you cant boost with a stock map sensor because of the added manifold pressures.
you can, but the check engine light will be on and the car runs in safe mode. honda MAP sensors arent designed to read positive MAP, hence cel on FI applications. the map sensor doesnt know how much fuel to add, thats why we need FMUs or chipped ECUs, or aftermarket MAP sensors so we dont blow motors. im using a MAP bypass, called missing link/obx fmu. OT, you might wanna check out that rattling..it might not necessarily be a bad pump, but perhaps something is loose?
 

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johnlude85 said:
most of the time you cant boost with a stock map sensor because of the added manifold pressures.
ksniperfox said:
you can, but the check engine light will be on and the car runs in safe mode. honda MAP sensors arent designed to read positive MAP, hence cel on FI applications. the map sensor doesnt know how much fuel to add, thats why we need FMUs or chipped ECUs, or aftermarket MAP sensors so we dont blow motors. im using a MAP bypass, called missing link/obx fmu. OT, you might wanna check out that rattling..it might not necessarily be a bad pump, but perhaps something is loose?

Wow, lots of bad information here. Let me set the record straight. First, the JRSC, while offering positive manifold pressure, is aft of the map sensor so the map sensor never sees the boost. It uses, in stock kit form, a relay to trick the ECU into dumping more fuel during boost. Kludgy at best, but a better alternative is the JR map controller, and better than that, a standalone ECU.
Secondly, honda map sensors ARE designed to read positive manifold pressures, but not much over 1 bar, IIRC. It is the ECU that doesn't know what to do with boost signals received by the map sensor. However, the placement of the map sensor on the manifold of a stock or JRSC'd engine is will always see vacuum and never boost. The only time it will ever see boost is if it is on a turbo'd or centrifugal SC'd car, or the map sensor is moved to the intake manifold on a JRSC'd engine, or by using the JR Map Controller which combines a vacuum hose from the IM to a block-off plate with an air nozzle to the map sensor so that it will see both vac and boost. Associated with the map controller is solid state electronics that will prevent the CEL and trick the ECU to dump more fuel during boost conditions. Missing links aren't used on JRSC'd vehicles. Neither a chipped ECU nor an aftermarket map sensor is necessary nor recommended.
 
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