420A Car will idle but will die when giving gas

[Paradox_Z3RO]

I have a 1999 Mitsubishi Eclipse RS 420A non turbo. I had the engine replaced but now the car will idle but soon as i give it gas it just dies.

The mechanic told me the PCM is not getting enough volts to the throttle body so i wanna now if its the TPS or just the PCM cause i used the PCM that i had originally and the one i had bought and got programed, both are still doing the same thing.

The motor sounds fine.

 

[steve]

Any codes?

 

[Paradox_Z3RO]

They are saying the codes that show are showing for the throttle body and that the pcm is showing low voltage. The car will start but soon as you give it gas it just dies. I changed the Throttle Position Sensor and still same thing going on. I dont know what codes show they didnt give me any when they scanned it. I swapped the pcm from the one that i had with the car and the one i bought from Flagship1 and still doing it. It could be the distributor but i highly doubt it but im gonna change that one too.

 

[steve]

I don't remember there being a distributor on the 420A. I thought it also had a crank and cam angle sensor that told the ECU what the timing was. Checking the FSM I see that I remembered correctly.

If you don't have a scantool or can't borrow one from the local autoparts store you might want to try using the keydance procedure that the 420A ECUs provide .

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[Paradox_Z3RO]

thanks for the help i will go to the store and pick up a new crankshaft sensor and see if that will fix the problem they put the camshaft sensor i bought for the old engine on this one and i know that should work right cause its brand new being the old engine didnt run right and needed to be swapped due to the other shop screw up of not making sure the crankshaft was tighten down

 

[Paradox_Z3RO]

well by distributor i mean the ignition coil on top of the engine just missed named it

 

[BLACK'98DSM]

For the time being, assume the ECU is not the issue. Just because it is unlikely for 2 separate units to have the same issue.

Check for a short or broken connection in the wiring for the throttle position sensor.

Also, just because the camshaft position sensor is new does not mean it is good. What brand is it? Some off the shelf brands and most Ebay brands are truly garbage when it comes to sensors for the 420a.

 

[waltah]

With a 2G car that has a smack-you-in-the-face problem I would get a scan tool -- all the auto parts stores both sell and rent them, most will come out to your car and do the test for you, for nothing. I'll almost guarantee that there are useful codes -- your problem sounds like a disconnected (or maybe defective) sensor and all those failures give codes.

OBD II isn't perfect but it does a whole lot and for a sudden serious 'engine don't run right' problem it's really the first thing to check.

Bring the code(s) here. Someone will help you figure out the next step.

 

[Paradox_Z3RO]

I have a P0122 Throttle/Pedal/Position sensor/ Switch A circuit low, P0106 Manifold Absolute Pressure / Barometric Pressure Circuit Range / Performance, and P1496 Manufacturer control. P1496 code i have never seen before. I have already switched the TPS Sensor and still the same thing im gonna get a new MAP sensor and see if that will fix anything but idk what to do about the manufacturer control

 

[waltah]

Codes P1000-P1999 are manufacturer-specific -- Ford's meaning is probably different from Mitsubishi's. Doing a search for 'P1496 mitsubishi' I get hits for '+5V supply voltage low.' That sounds like either a wiring harness problem -- most likely a short -- or a bad ECM since the +5V supply is located there.

I would check the voltage to the TPS since one end of it gets +5V and you also have a TPS code. I'd do this first with it disconnected and ignition on, then with it connected.

Note that this is also what your mechanic said. You've now substituted both the TPS and PCM, right? So that suggests a harness problem (or possibly another sensor that gets +5V supply) and continuity/short circuit checks seem logical.

Power supply problems are 'root' problems -- they will cause symptoms in other and often multiple places. So when you get one that's a good place to start troubleshooting.

 

[Paradox_Z3RO]

i do notice a slight buzzing sound when the ignition is turn on but idk where its coming from