8.1 Vortex - Hard Starting

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Heli_av8tor

Heli_av8tor

Well-known member
Joined
Mar 3, 2017
Posts
1,088
Location
NW Illinois
Stopped for gas yesterday and took several tries to restart. Always popped right off before.
Have started 5 times or so since and has been reluctant to start. Haven?t hooked up code reader yet but no Check Engine light.
Runs great once started.
Any ideas?
 
70 degrees. Cranking normally.

Checked for code and none stored.

Will have to research fuel pressure regulator. Won?t be able to check while on the road.
 
Just a warning. There was a recall on the 8.1 over a "Fuel Rail Clip" that is the clip that holds the fuel regulator it turns out (Found out when my engine went BOOM, not related.. I just got to see it).

NOTE if that clip fails you won't start period.

If it does not happen again.. Do not worry

 
The first thing I would try is to turn the key to the "on" position and leave it of for a few seconds, maybe do this two or three times before you try and turn the engine over, then try starting the engine, if it fires right up, then you are either losing fuel pressure, or it is not building fuel pressure as it should. Another, possibility is the fuel filter, and thirdly the fuel pump.
 
Fuel filter was replaced 1800 miles ago. Plugs and wires 1500 ago.

Paul, will try your suggestions in the morning. Too bad there?s not a fuel pressure sensor that can be read by OBD.

SeaFoam wouldn?t hurt but I doubt it could help either. Engine just runs perfectly once started.
 
If it starts hard when the engine is warm, it could be a choke issue.

The choke is designed to engage for cold starts and then will disengage once the engine is running.

If you stop for fuel and then restart the engine, the choke won't be needed but if it does engage, hard starting will be the result.

Does the engine start hard when it is cold?

In the fuel injection age, changing the fuel to air mixture is typically done by the computer. It may be that a sensor is bad and giving a wrong signal or possibly a mechanical response failure.
 
so, engine spins but slow to fire?
Is that what we are talking?
Or is it turning over slower than usual before firing?

 
Fuel pump relay? That?s where I?d look first, especially if the key flip flopping helps. My experience with failing fuel pump relays is first hard starting, then progresses to (heart stopping) just randomly dies usually pulling away from stoplight or such.
 
No choke on these EFI engines. Spins fine just slow to fire.

Turning the key on for 10 seconds or so has mitigated but not cured the problem.

Glad to hear that this is a typical beginning failure mode for the relay. Definitely the simplest fix.
Arrive in Minot ND tomorrow for a week stay. May switch the relay out there.

 
If your problem is that the fuel pressure is not holding, then keeping the key in the "on" position for 2 or 3 seconds should work better as by keep the ignition in the "on" position for 10 seconds would probably result in the fuel pump running two or three seconds, then allowing the pressure to bleed off the rest of the ten seconds.
 
The fuel and air mixture is different when starting cold compared to starting hot.

Are you experiencing the same issue when cold starting?
 
Same hot or cold.

Shortened the ?on? time this morning and it seemed to catch a little quicker.

The leak-down? path would either have to be through an injector or backwards through the pressure regulator. (?)    Pretty sure it?s not dumping gas externally (no gas smell anyway).
 
I think the pressure regulator and the pump are one of the same and are commonly mounted in the gas tank. It does seem likely to be a pump/regulator problem. I read a thread somewhere that stated that the pump has a time limit when the ignition is turned to the on position. After reading, it seems that with the key in the on position before starting, the pump will shut down on either pressure or the timer. Which ever comes first. I couldn't verify that information but I am still looking. It could be that the pump is venting pressure back to the tank. It would seem unlikely that an injector would be leaking as I would think that would cause a problem while the engine is running.
 
Found this info for the 2004 workhorse chassis.

http://www.irv2.com/forums/f22/fuel-rail-pressure-regulator-on-8-1-workhorse-258736.html


One of the posts in the above thread reads as follows:


"If your chassis is a 2004 (4 is the 10th digit of the VIN) then you don't have a regulator at the rail, it is actually a dampener. The regulator is back at the pump. The part number for the dampener is 12575013."


The above may not apply to your 2004 Pace Arrow. It is possible that your 2004 Pace arrow was built on a 2003 chassis.



Here is another link to a repair of a pump not holding pressure

http://www.irv2.com/forums/f22/w22-2004-vortec-8-1-fuel-pump-pressure-193627.html

"I had these symptoms several years ago. It was caused by the failure of the internal fuel pump check valve . Instead of dropping the tank and replacing the pump, I found an external check valve that I installed on the fuel line between the tank and the fuel filter. This has proved to be a cost effective repair so far. The check valve cost about $15 back then."


Hope this helps and good luck.
 
Thanks Henry. I found both of those posts today. Mine is the ?04 so should have the regulator and check valve in the pump.

At this point I?ve learned to deal with it and will be ok until I get home if it doesn?t get worse.

Not looking forward to dropping the tank. Arg!
 
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