Ok guys I have had this car for 3 years bought it not running. Had to install a new engine harness and replace ecm due to water damage. Installed parts and car starts and runs beautifully for 30-45 seconds then dies setting a p0191 code. Replaced filter, pump, and fuel pressure sensor and car still will not run. What am I missing here?

 

Hi Erik,
Did you replace the entire fuel pump assembly or just the motor?

 

I replaced the entire assembly with the very expensive Delphi replacement.

 

Code refers to fuel pressure sensor located on the fuel rail.

Check vacuum connection to this since it may be cracked and leaking.

 

Everything on this fuel system is new within a week. I'm testing voltage to fuel pump and have voltage when key on for priming then once car starts there is no voltage to it

 

You need to measure the fuel rail pressure with a mechanical gauge and also the value from the fuel rail pressure sensor (OBD II reading) and let us know what it is. Do you have a scanner tool? You are looking for ~ 55 PSI at idle.

I would like to know the pressure when you are priming, and what it does after you start it.

 

Fuel pressure is 53 at prime once car is started then falls off to almost nothing. I'm starting to wonder if the ecm is not commanding the pump to run once started.

 

I am wondering that as well. Someone with more knowledge than me will hopefully chime in, but it might be an anti-theft issue with changing the ECU.

 

I was wondering that. The company I sent it to claimed everything would be plug and play when I received the parts back. I had to send the ecm instrument cluster and key fob for the programming

 

As I understand it, the VIN code in the ECM has to match that of the vehicle.

 

Yes and what my scanner is showing it does

 

Hmmm. I'll think more about it, but hopefully someone else has some better ideas.

 

Do you know someone that has a SDD, or access to one?
Maybe it could program things to work together, & play nice?
Worth a try if you do, really don't know if it would work

 

Did you measure that with a mechanical gauge or from the OBD II (FRP sensor)?

When you first activate the ignition, the ECM will transmit a brief compulsory (I think) signal to prime the pump for a short duration. So, there might be some token signal that is triggering the ECM to shut off the fuel pump, and the engine running for a brief time is merely a result of the initial prime signal.

The good news is that the pump is working and receiving the signal. I am not sure if the fuel cutoff switch interrupts the priming signal, but I imagine it does. However, I think it is worthwhile to check the cutoff switch anyway.
-j

 

What do you mean everything has been programmed already to work together. Everything ive read if it was not soon as the car is turned on it would lock it up in security.. Ive gone through the diagnostics for this code and seem to have 4.2 volt on my signal wire and manual doesnt want to see over 3 so im wondering if i have a bad sensor now.

 

You should have a PATS sensor mounted in the center of the defroster panel at the base of the windshield.
What is the red light doing when you turn the key on? When you attempt to crank the car?

The GIANT red flag I see is the instrument cluster and key. I would never replace those and simply program one or more keys to your car. I hope this is fixable. Do you still have the original parts??
Why did you replace everything?
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The ecm instrument cluster and key was all programmed together.

 

What company did you use?

 

Would it throw a P0191 if the anti theft is triggered?

 

Sos diagnostics