Thread: Car starts then rpm gauge drops immediately

I need help I replaced both 02 sensors, map, maf and iac sensor, also the fuel pump and filter. Now car won't stay on what did I do wrong

Sent from my SM-N910T using Tapatalk

Do you still have pressure in the fuel rail after the car shuts down? Almost sounds like it's not feeding it fuel after the initial prime when you turn the key on.

Yea fuel is getting to it do you think it could be the Ignition control module

Sent from my SM-N910T using Tapatalk

Originally Posted by SubwayBrat

Will it stay running at all? Or does it drop low and shoot back up?

No it start and dies right after start up

Sent from my SM-N910T using Tapatalk

Originally Posted by Fivefingerdeathpunch

I'd even unplug the new maf sensor and see if it can run.

Thanks I unplugged the new maf sensor and it works so I guess my wire harness is damaged?

Sent from my SM-N910T using Tapatalk

^this^ The aftermarket MAF's for these cars can suck. I'd rather go to a JY and get a MAF than hassle with trying to get a new one to work out of the box from what I've seen. Or get a genuine Delco MAF as FFDP said.

Originally Posted by mguzzo

why won't it run? Air, fuel, spark
diagnose instead of throwing parts at it.

fuel: you've replaced the filter and pump. Was it an OEM pump or aftermarket?
Get under the car, disconnect the line from the pump into the filter. Put a container under the end of the hose.
Key on without starting, listen for the pump to run and shut off. Did any fuel come out? if not your new pump is f*cked. I had two new airtex pumps crap out in one week because the check valve stuck closed and the system would not prime.

OK so if fuel came out leave the line disconnected. Unscrew the filter. Go the the front of the engine and use an air line through the to purge the fuel lines from front to back. reconnect the filter and fuel line from the tank.

Reprime a couple times, press the fuel needle valve and make sure gas comes out. Better yet use a pressure gage to check. You should have at least 50 psi at the rail and the pressure should not drop after prime.

Find the diagram for bypassing the fuel pump resistor by bending the relay tab and do that.

Next remove a spark plug then reconnect the wire from the coil. Crank the engine. If you have spark then your ICM and crank position sensor are good. If no spark you need to investigate further.

It started running after I unplugged the maf connector so what could be the problem

Sent from my SM-N910T using Tapatalk

Originally Posted by ScottyDoggs

why did you change all those parts in the first place? theres more going on i bet.

Because I thought the sensors went bad because the engine would die on me while I'm driving

Sent from my SM-N910T using Tapatalk

Originally Posted by ScottyDoggs

thats the crank sensor 99% of the time. the tach ever just quit working? then stall?

The rpm gauge would drop to 0 and the car would stop moving

Sent from my SM-N910T using Tapatalk

I replaced the crankshaft position sensor before do you think that could cause the engine to die at idle?

Sent from my SM-N910T using Tapatalk

Originally Posted by ScottyDoggs

the harness to the crank sensor maybe bad. mine was. it ever set a code?

My check engine light never been on

Sent from my SM-N910T using Tapatalk