Car hard to start after sitting one day
08-20-2007, 02:58 PM
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Car hard to start after sitting one day Had the car for about a month now and pretty much drive it everyday, starts right up. However, when i drive another car for a day, the Formula is almost impossible to start the next day. Fuel pump primes when key turned to "ON", but car just cranks and cranks. Takes about 4-5 tries for it finally to start and when it does it hesitates until it gets fully running, then its perfect until i let it sit for a day without driving it. Anyone have any ideas??
08-20-2007, 03:12 PM
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08-20-2007, 04:11 PM
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How could the pump be going out? he says the car runs perfect after it warms up. Same fuel pump when he starts the car and when hes driving, no? 
and i had a hard start on my 94 formula, the 1-way check valve was shot in the fuel pump. But, the car always took forever to start, sitting or not. The fuel pressure went to 40, then when the pump stopped priming, shot way down to 0. so my story doesn't help him
I think it could be carbon deposits on the intake valves
why? because the carbon acts like a sponge to fuel.
When you let the car sit, the carbon loses all of the fuel, and it turns into a sponge. Now you go to start it up, the carbon sucks a lot of the fuel that the injector spits out, hence your car runs like **** at start up. When the carbon gets full of fuel and it cannot take in anymore, the car will run fine.
Thats just my 2 cents.
and i had a hard start on my 94 formula, the 1-way check valve was shot in the fuel pump. But, the car always took forever to start, sitting or not. The fuel pressure went to 40, then when the pump stopped priming, shot way down to 0. so my story doesn't help him
I think it could be carbon deposits on the intake valves
why? because the carbon acts like a sponge to fuel.
When you let the car sit, the carbon loses all of the fuel, and it turns into a sponge. Now you go to start it up, the carbon sucks a lot of the fuel that the injector spits out, hence your car runs like **** at start up. When the carbon gets full of fuel and it cannot take in anymore, the car will run fine.
Thats just my 2 cents.
08-20-2007, 04:34 PM
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Originally Posted by ThoR294
How could the pump be going out? he says the car runs perfect after it warms up. Same fuel pump when he starts the car and when hes driving, no?
and i had a hard start on my 94 formula, the 1-way check valve was shot in the fuel pump. But, the car always took forever to start, sitting or not. The fuel pressure went to 40, then when the pump stopped priming, shot way down to 0. so my story doesn't help him
I think it could be carbon deposits on the intake valves
why? because the carbon acts like a sponge to fuel.
When you let the car sit, the carbon loses all of the fuel, and it turns into a sponge. Now you go to start it up, the carbon sucks a lot of the fuel that the injector spits out, hence your car runs like **** at start up. When the carbon gets full of fuel and it cannot take in anymore, the car will run fine.
Thats just my 2 cents.
and i had a hard start on my 94 formula, the 1-way check valve was shot in the fuel pump. But, the car always took forever to start, sitting or not. The fuel pressure went to 40, then when the pump stopped priming, shot way down to 0. so my story doesn't help him
I think it could be carbon deposits on the intake valves
why? because the carbon acts like a sponge to fuel.
When you let the car sit, the carbon loses all of the fuel, and it turns into a sponge. Now you go to start it up, the carbon sucks a lot of the fuel that the injector spits out, hence your car runs like **** at start up. When the carbon gets full of fuel and it cannot take in anymore, the car will run fine.
Thats just my 2 cents.
Of course your story helps. It sounds pretty much exactly like his story. Except yours was just worse. His check valve might only stick so far, so the fuel drains back slowly.
As for the pump going out, it doesn't hurt to speculate.
08-20-2007, 05:15 PM
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I was leaning toward the check valve in the pump as well. Ive had a few go bad before, but usually it does it all the time, not just after sitting. Ill get a rail gauge tomorrow and see what its doing when it doesnt sit, and when it does. Rather check that first than go ripping out the fuel tank. thanks for the help guys
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08-20-2007, 08:21 PM
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While you've got a gauge on it and see if it holds pressure. That'll either be a leaky injector or a bad pressure reg. I'm sure you know that though.
My guess, if it WAS a leaky injector, it would have to be a few and then have too much fuel in more than just one cylinder. If it was one, then the other 7 would just fire and push out the flooded cyl :\
My guess, if it WAS a leaky injector, it would have to be a few and then have too much fuel in more than just one cylinder. If it was one, then the other 7 would just fire and push out the flooded cyl :\
08-20-2007, 09:45 PM
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Loss of immediate pressure can be leaky injector(s), regulator, or check valve. If i remember correctly, if i have someone turn the key and prime the pump, I can clamp the soft feed line at the tank and if it holds, the check valve is bad. If I clamp the return line and it holds, its a bad regulator. I think it would take more than one leaky injector in an 8 cylinder to cause this problem, but, I have seen stranger things. Ill check it out over the weekend and post back my findings, thansk again guys
08-21-2007, 03:06 PM
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it may not be nearly as big a problem as you think it is... I had this exact same problem, if i let the car sit for more than an hr or so it would be hard to start and then run weird and i'd shut it down and restart it and it'd be fine, or if i let it sit longer it would even stall 2-3 times right after i started it before i could get it to run at all...it also failed emissions due to high levels of Nox and HC
after doing a few small things like running fuel injector cleaner through it and getting the fuel filter changed i was thinking injectors but decided to just pay the $110 diagnostic fee to get it looked at....
it ended up being my intake elbow.. it was worn and leaking unfiltered air into the system while the car was sitting, and when i went to start it up, the computer thought it was leaning out so it would throw fuel at it and flood itself.....
After paying the $110 diag i told the shop to just leave the elbow how it was (they taped it up and said it was running good but needed a new one for a perminant fix) and rather than buying a new oem one i got a black powdercoated one from summitt. The car idles much better now, starts on a very short crank, and i took it today and had the emissions retested and my numbers which were 2.7 for Nox (allowed is 2.5) and 1.5 for HC (allowed is .80) were down to .30 and .13
They didnt even finish the whole test, they saw the numbers that low and immediatly passed it
after doing a few small things like running fuel injector cleaner through it and getting the fuel filter changed i was thinking injectors but decided to just pay the $110 diagnostic fee to get it looked at....
it ended up being my intake elbow.. it was worn and leaking unfiltered air into the system while the car was sitting, and when i went to start it up, the computer thought it was leaning out so it would throw fuel at it and flood itself.....
After paying the $110 diag i told the shop to just leave the elbow how it was (they taped it up and said it was running good but needed a new one for a perminant fix) and rather than buying a new oem one i got a black powdercoated one from summitt. The car idles much better now, starts on a very short crank, and i took it today and had the emissions retested and my numbers which were 2.7 for Nox (allowed is 2.5) and 1.5 for HC (allowed is .80) were down to .30 and .13
They didnt even finish the whole test, they saw the numbers that low and immediatly passed it
08-21-2007, 04:21 PM
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Wow, in all my years in cars, never heard of that. Guess anythings possible though, Ill check it out. Bad news, now the car seems to not want to start all of the time, guess thats what I get for looking into fixing it. Im going to hook up a gauge on the rail soon, if it turns out its the check valve, I really dont want to drop the tank in this car, looks like a PITA. Is there anyway to install an inline check valve to hold pressure in the line on startup? If the pump itself is fine, Id rather not get into dropping the tank....
08-21-2007, 05:02 PM
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Originally Posted by 87lc2
Wow, in all my years in cars, never heard of that. Guess anythings possible though, Ill check it out. Bad news, now the car seems to not want to start all of the time, guess thats what I get for looking into fixing it. Im going to hook up a gauge on the rail soon, if it turns out its the check valve, I really dont want to drop the tank in this car, looks like a PITA. Is there anyway to install an inline check valve to hold pressure in the line on startup? If the pump itself is fine, Id rather not get into dropping the tank....
08-21-2007, 05:09 PM
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Originally Posted by 1995blacktattop
it may not be nearly as big a problem as you think it is... I had this exact same problem, if i let the car sit for more than an hr or so it would be hard to start and then run weird and i'd shut it down and restart it and it'd be fine, or if i let it sit longer it would even stall 2-3 times right after i started it before i could get it to run at all...it also failed emissions due to high levels of Nox and HC
after doing a few small things like running fuel injector cleaner through it and getting the fuel filter changed i was thinking injectors but decided to just pay the $110 diagnostic fee to get it looked at....
it ended up being my intake elbow.. it was worn and leaking unfiltered air into the system while the car was sitting, and when i went to start it up, the computer thought it was leaning out so it would throw fuel at it and flood itself.....
After paying the $110 diag i told the shop to just leave the elbow how it was (they taped it up and said it was running good but needed a new one for a perminant fix) and rather than buying a new oem one i got a black powdercoated one from summitt. The car idles much better now, starts on a very short crank, and i took it today and had the emissions retested and my numbers which were 2.7 for Nox (allowed is 2.5) and 1.5 for HC (allowed is .80) were down to .30 and .13
They didnt even finish the whole test, they saw the numbers that low and immediatly passed it
after doing a few small things like running fuel injector cleaner through it and getting the fuel filter changed i was thinking injectors but decided to just pay the $110 diagnostic fee to get it looked at....
it ended up being my intake elbow.. it was worn and leaking unfiltered air into the system while the car was sitting, and when i went to start it up, the computer thought it was leaning out so it would throw fuel at it and flood itself.....
After paying the $110 diag i told the shop to just leave the elbow how it was (they taped it up and said it was running good but needed a new one for a perminant fix) and rather than buying a new oem one i got a black powdercoated one from summitt. The car idles much better now, starts on a very short crank, and i took it today and had the emissions retested and my numbers which were 2.7 for Nox (allowed is 2.5) and 1.5 for HC (allowed is .80) were down to .30 and .13
They didnt even finish the whole test, they saw the numbers that low and immediatly passed it
08-21-2007, 05:53 PM
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Originally Posted by 87lc2
I hope im that lucky! Where on the inlet elbow was it leaking?
on the bottom side, up by the throttle body i think... thats where all the duct tape was when i took the elbow off to replace it with the Trick Flow one
