Fuel System-related hard start problem help needed

[PhoenixGTS]

Last weekend I finished the project of replacing serpentine belt and having the intake manifold and valve covers powder coated. Everything went well, but now I am having a hard start problem that I think is fuel related. Here are the facts:

1) car has never had hard start problem since I got it.
2) When I bled the fuel line with the pressure testing schrader valve above cylinder 10 before disassembling the fuel hose, nothing came out.
3) went I disconnected the quick release fitting of the fuel line down the firewall on the driver's side I got a little fuel spillage but not as much as I anticipated.
4) when I took the intake manifold off some fuel spilled out of the rails, but not as much as I anticipated.
5) before reassembly I thoroughly cleaned the intake manifold including submerging it in water and bubbling compressed air through the fuel rails.
6) the small o-ring that seals the main fuel line to the back of the intake manifold was injured so I replaced it.
7) corrected throttle-body sequencing as the passenger side was opening before and more than driver's side.
8) reassembled everything, plugged all hoses and plugs in and car started right up after maybe one crank revolution. No hint of any leaks either visibly or by fuel fumes.
9) car sat over night and started up immediately in the morning.
10) car sat all day while I was at work, and when I tried to start it, at first it turned over about a half a rev and then stopped like something was jammed between the starter and flywheel. Did it again of second try. I was worried that I managed to get something caught in the fan belt so I looked and everything was good. Tried 3rd time and it turned over for maybe 10 seconds before starting. Seemed as if the fuel rails were empty and took a while to fill them up, but then again, it seems to help when I cracked the throttle a bit (reminded me of the old carburetor days).
11) idle a little weak at first, but in 10 seconds of running cars seems to run fine.

So I am thinking that I am losing fuel pressure while the car sits, but with an electric pump, I cannot see this lasting 10 seconds. Is there a check ball valve or something to keep the fuels rails pressurized? I was really surprising that there is not fuel return line and that the fuel rails are dead ends.

Other idea is that closing up passenger side t-body slightly has changed idle air somehow and that is why opening the butterflies a bit seems to help.

With the odd starter problem, is it possible my battery is starting to go, is not pushing the fuel pump sufficiently at start up, but somehow having enough juice to crank?

I need some ideas of where to go.

 

[Qualitywires.com]

did you throw a code?

 

[PhoenixGTS]

did you throw a code?

I do not see a check engine light, but I do not have a scanner to pull real codes.

I forgot to mention that once it starts and runs smooth, if you turn it off then start it up again, its starts instantaneously. Totally normal. This indicates to me it is a fuel drain-down issue.

 

[Ulysses]

car sat all day while I was at work, and when I tried to start it, at first it turned over about a half a rev and then stopped like something was jammed between the starter and flywheel. Did it again of second try.

Low fuel pressure isn't going to keep your starter from turning the engine over. A low battery will.

Listen to your stereo much while you were working on it?

 

[PhoenixGTS]

Low fuel pressure isn't going to keep your starter from turning the engine over. A low battery will.

I gave the info thinking that maybe the two happenings were related since both the starter and fuel pump are electric powered. It is not doing the turn-over problem anymore, but after sitting for an hour at lunch it took about ten seconds and some throttle to start. But then when I got back to work I shut it off, then tried to start it and it lit right up like normal.

 

[Ulysses]

Just for comparison,

the day my battery died and left me stranded at a gas station, I started out from home with a hard to start car. First try at starting resulted in a half a rev, then nothing. Next attempt at a start resulted in maybe 3 or 4 revs with finally catching, then rough idle for a few seconds, then it smoothed out and ran fine. Took a short trip to the gas station before venturing out and shut her down at the pump. Filled up, got in and tried to start her up. Nothing but crank crank crank crank. Tried several times until I noticed that the cranks were starting to slow down. Right there I knew that the battery was giving up the ghost.

My trip to the gas station was short, but your trip to work may have been long enough to put a bit of charge on top of the battery.

 

[PRVT JET]

To see if it's fuel pressure related, you can try two things. First, cycle the key to the on position 4-5 times before starting. Always listen for the fuel pump. second, crank the car without starting, than try to start. If the car fires up normally both ways, than you don't have full pressure at start up. It could mean you need a new fuel pump or a new fuel pressure check valve.

Isaac

 

[PhoenixGTS]

To see if it's fuel pressure related, you can try two things. First, cycle the key to the on position 4-5 times before starting. Always listen for the fuel pump. second, crank the car without starting, than try to start. If the car fires up normally both ways, than you don't have full pressure at start up. It could mean you need a new fuel pump or a new fuel pressure check valve.

Isaac

Fuel Pressure Check Valve! That seems exactly like the kind of problem I have. Where is it and could I have done something to it during my disassembly and reassembly? Sorry I am at work so I don't have my service manual handy to look things up.

EDIT: I just called my dealer and their Viper tech and parts guy said there is no check valve and only the pump pressurizes the fuel rails.

 

[PRVT JET]

From my understanding, the fuel pressure check valve is the one you mentioned, on top of the intake(passenger side). My car started doing that when I had nos installed, I run the fuel line from there, I did order a new fuel pump just in case. Call sean roe, he was the one that told me to check for that.

 

[PhoenixGTS]

From my understanding, the fuel pressure check valve is the one you mentioned, on top of the intake(passenger side). My car started doing that when I had nos installed, I run the fuel line from there, I did order a new fuel pump just in case. Call sean roe, he was the one that told me to check for that.

Yeah that schrader on the intake manifold above cylinder 10 is the opening you use to check and make sure you have sufficient pressure, but it is nothing other than a port and does not help the system hold pressure. It is basically a valve stem like from a wheel in your fuel system. It is not leaking so it looks good.

 

[PhoenixGTS]

Just for comparison,

the day my battery died and left me stranded at a gas station, I started out from home with a hard to start car. First try at starting resulted in a half a rev, then nothing. Next attempt at a start resulted in maybe 3 or 4 revs with finally catching, then rough idle for a few seconds, then it smoothed out and ran fine. Took a short trip to the gas station before venturing out and shut her down at the pump. Filled up, got in and tried to start her up. Nothing but crank crank crank crank. Tried several times until I noticed that the cranks were starting to slow down. Right there I knew that the battery was giving up the ghost.

My trip to the gas station was short, but your trip to work may have been long enough to put a bit of charge on top of the battery.

The heat down here eats batteries (never had one last over two years) so maybe a new Optima would be a great place to start. I figure that if the fuel system is not leaking it must be fine since it is so simple.

 

[VPRVENM97]

EDIT: I just called my dealer and their Viper tech and parts guy said there is no check valve and only the pump pressurizes the fuel rails.

The check valve is in the fuel pump module. That check valve keeps the fuel system under pressure while the engine is off. If the check valve is malfunctioning, you'll lose fuel pressure while the engine is off. When you go to start the engine, it'll take several cycles of cranking before the engine turns on.

Cycle the ignition switch on and off about 5 times. If it starts normally, then your problem is most likely the check valve in the pump module. Mine did that at about 12K miles. Had to replace the entire fuel pump module at about $300 (with VCA discount). Replace the fuel filter while you're at it.

 

[Ulysses]

The check valve is in the fuel pump module.

I second that. Time to educate the dealer. Do you have a fuel pressure gauge? Pressure it up and check if it's within spec, note the reading. Let it sit over night and then check it again. That'll give the definite answer to the fuel pressure question.

 

[PhoenixGTS]

The check valve is in the fuel pump module. That check valve keeps the fuel system under pressure while the engine is off. If the check valve is malfunctioning, you'll lose fuel pressure while the engine is off. When you go to start the engine, it'll take several cycles of cranking before the engine turns on.

Cycle the ignition switch on and off about 5 times. If it starts normally, then your problem is most likely the check valve in the pump module.

I have another idea, and it is not pretty. What if the little o-rings on the spray end of the injectors are leaking? I would not see any leak since it would be into the engine and I would not smell any leak unless I stuck my nose in the airbox (which I will do now), but it would allow the rail pressure to bleed off. Reason I thought of this is that I noticed the coaters did not properly block off the injector holes and a little bit of blasting material got in there. I don't think it reached down into the little hole for the little o-ring, and the top ring seem to be sealing fine, but who knows.

 

[pullshard]

Is your car smoking (black) when it finally fires up? If that is the case you may have injectors which are leaking down. Or it could very well be powder coating which is causing this. That stuff goes on pretty thick.
Your car does have a check valve (maybe). Some tuners take it out so the car will crank over a few times, which in-turn lubricates internals before it fires up. Mine is that way, but it only takes about 3 to 4 revs before it catches.

 

[PhoenixGTS]

Identified the problem

Thought long and hard about what was going on, and figured it was way too much of a coincidence to have either the battery or check valve go at the same time I had the car apart. Remembering that I did not replace the o-rings on the injectors, and that it was very hard to get them re-intalled, I figured I must have hurt one or more o-rings and the system was leaking into the engine. No black smoke on start up, but recall my starter turn-over problem. Could that possibly have been hydro-lock in one cylinder due to it being full of leaking gas? As a precaution I will change the oil once I solve this problem. Anyhow, I removed injector #9 this morning so I could take it to the o-ring store (Dodge tells me you cannot buy them separately) and buy replacement o-rings. Sure enough the lower small ring was severly injured. Hopefully once I put all new o-rings on the injectors I will be good to go. The service manual does not have any sizing or specs for the o-rings, so if anyone happens to know the specs please shout out.

 

[Ulysses]

Re: Identified the problem

Don't know the specs, but if you bring it to a place that sells orings (usually they sell plastic tubing as well) they'll take a caliper to it and get you the correct size on the spot. Sounds like you are on the right track. You definitely could have had hydro lock, but you would think that after that event you would have ignited some blow by or had dark smoke or something.

 

[PhoenixGTS]

Re: Identified the problem

Don't know the specs, but if you bring it to a place that sells orings (usually they sell plastic tubing as well) they'll take a caliper to it and get you the correct size on the spot. Sounds like you are on the right track. You definitely could have had hydro lock, but you would think that after that event you would have ignited some blow by or had dark smoke or something.

I agree that if there was enough fuel in a cylinder to cause a physical impediment that it would have ben beyond pig rich and blown black smoke. But not only did it not do that, it did not even smell funny. Plus, after sitting all night, when I went to release pressure through the pressure checking port it hissed and released some pressure, so the leak must be tiny.

 

[PhoenixGTS]

Problem solved

Solved the fuel pressure leak down problem. When I re-assembled the injectors into the manifold, apparently the little o-ring on the bottom had swelled slightly and the oil I applied to help lube them (per the service manual) was insufficient to let them slip into place so I really had to force them. Upon removing the injectors I found that I had injured each and every lower little o-ring. Replaced all the o-rings and greased them with assembly lube for installation. They went right into place which tells me that the old ring must have swollen somehow. Fuel pressure is not leaking down so hard start problem is gone. Only $60 for injector o-rings overnighted so not too bad for a Viper problem.