[Notyepcars]

I bought a used 2010 enclave not running with 190k on it. Replace the timing gears and chains, had the valves tested, and reassembled with new gaskets. Engine is very hard starting, fires right away, but barely stays running. After about 2 minutes, it comes out of it and runs and sounds fine. It has the P0087 and p0089 fuel pressure codes, and a P0449 evap code. If I delete these codes, they instantly reappear and dash says engine power reduced. Im going to replace the sensor in the fuel rail, but doubt anything will change. Any ideas? Thanks

 

[JayS]

Get a code scanner that can read real time info and log the two fuel pressures in real time. In ODB Fusion (the app I use on my phone with a $20 Veepeek dongle from Amazon) "Fuel Rail Pressure" was the pressure from the high pressure pump and "Fuel Rail Pressure (gauge)" was the fuel pressure from the low pressure pump in the tank. High should be 500-800, low should be around 60. High will fluctuate a bit at idle but should stay in that range. Low pressure side should jump to 60 as soon as you turn the key to on (before you crank). High pressure pump is driven off a cam on the engine so it won't fire until the engine is cranking.

 

[rbarrios]

When i got p0089 along with 2 other codes, i replaced the hpfp...
Codes never came back.

 

[Notyepcars]

.

 

[Notyepcars]

This is a screenshot of the pressures when it was warmed up. I’ll put the new rail pressure sensor in tomorrow and watch where the pressures are at when I first try to start.

 

[JayS]

Ok, but you said it runs fine once it's warmed up. What are the pressures when it first starts and it’s stumbling? My guess is either the low pressure pump isn’t getting fuel to the high pressure pump or the high pressure pump isn’t firing. My money is on the high pressure pump.

Codes P228c and P0089, had to replace the high pressure...

This happened a month ago but just getting around to making a post. My wife drove our 2013 Enclave with just under 100k miles home from work with no issues. Went to leave about 30 minutes later and it was hard to start, then misfiring badly and the the CEL came on. She called me and I told her...

www.enclaveforum.net

 

[kenphebus]

I bought a used 2010 enclave not running with 190k on it. Replace the timing gears and chains, had the valves tested, and reassembled with new gaskets. Engine is very hard starting, fires right away, but barely stays running. After about 2 minutes, it comes out of it and runs and sounds fine. It has the P0087 and p0089 fuel pressure codes, and a P0449 evap code. If I delete these codes, they instantly reappear and dash says engine power reduced. Im going to replace the sensor in the fuel rail, but doubt anything will change. Any ideas? Thanks

Did forget the plunger that rides on the cam that pushed the high pressure pump? I did pnce and had similar codes

 

[JayS]

I skipped replacing the cam that fires the pump when I did mine because it didn’t look worn at all.

 

[Notyepcars]

I replaced sensor in rail with no change, and low pressure is working and holding pressure. High pressure pump arrived today, so i install that tomorrow and see what happens.

 

[JayS]

It is worth the struggle to get that bottom bolt out without removing the coolant pipe. And it will be a struggle. Have a 10mm deep 1/4" drive on hand, plus a regular 10mm 1/4 drive with a short 1/4 drive extension. Avoid the temptation to remove the top one first because it's easier, because that will just put tension on the bottom one when the spring on the pump pushes against it. With the top one still snug once you break the bottom one loose you should be able to awkwardly spin it out mostly by hand, then remove the top one.

 

[Notyepcars]

Well I installed the new high pressure pump and now it won’t start. Fires a few times, but won’t run at all. Throwing P0122 and P0223 throttle body codes, with some misfire codes. Cleaned throttle bony connection with contact cleaner, cleared codes and disconnected battery for a hour with no change. What’s going on?

 

[rbarrios]

Just curious, did you use a GM pump or aftermarket?
Ive read that aftermarkets actually pump higher amounts of fuel than the gm spec pump.

 

[JayS]

You sure you didn’t leave something unplugged? Quite a bit gets disconnected to get to the high pressure pump.

 

[kennethphebus]

Not sure if you found the solution but commonly the purge valve sticks open sucking air making it hard to start. If you top off your gas tank it will be hard to start becuase it is sucking up fuel. Pull the cove off the motor by removing the oil cap, you will find the purge valve in center of motor. it has one hose and a screw holding it in. Pinching the hose at the push tabs will release the hose. Start the motor up, if air is sucking at the valve then replace it