[Z06] Hard starting issue 03 z06
Racer
Joined: Nov 2012
Posts: 376
Likes: 0
highly doubt its a fuel filter unless your having wot problems also
it takes more fuel to do a wot pull than it does to run your car and if it was clogged it would just make your fuel pump run even harder to keep the fuel pressure that the rail wants to see...
smell your oil.. if it smells like gas than your o-rings are leaking and washing past your cylinders into your oil..
definatly not a bad idea to change your fuel filter as it is a common maintanence item put i dont think its gonna help your issue.. i would believe a dying fuel pump over a filter
it takes more fuel to do a wot pull than it does to run your car and if it was clogged it would just make your fuel pump run even harder to keep the fuel pressure that the rail wants to see...
smell your oil.. if it smells like gas than your o-rings are leaking and washing past your cylinders into your oil..
definatly not a bad idea to change your fuel filter as it is a common maintanence item put i dont think its gonna help your issue.. i would believe a dying fuel pump over a filter
Thread Starter
Drifting
Joined: Oct 2008
Posts: 1,793
Likes: 63
From: Staten Island/NJ NY/NJ
highly doubt its a fuel filter unless your having wot problems also
it takes more fuel to do a wot pull than it does to run your car and if it was clogged it would just make your fuel pump run even harder to keep the fuel pressure that the rail wants to see...
smell your oil.. if it smells like gas than your o-rings are leaking and washing past your cylinders into your oil..
definatly not a bad idea to change your fuel filter as it is a common maintanence item put i dont think its gonna help your issue.. i would believe a dying fuel pump over a filter
it takes more fuel to do a wot pull than it does to run your car and if it was clogged it would just make your fuel pump run even harder to keep the fuel pressure that the rail wants to see...
smell your oil.. if it smells like gas than your o-rings are leaking and washing past your cylinders into your oil..
definatly not a bad idea to change your fuel filter as it is a common maintanence item put i dont think its gonna help your issue.. i would believe a dying fuel pump over a filter
injector o-rings can go bad from not using the car i assume?
only have that problem on startup?
Thread Starter
Drifting
Joined: Oct 2008
Posts: 1,793
Likes: 63
From: Staten Island/NJ NY/NJ
But I am just trying to figure out what else it could be in the meantime
Race Director
Joined: Jan 2008
Posts: 16,028
Likes: 170
From: oregon
you can kind of guess with fuel pressure. go out. turn the key to on so the fuel pump primes but not to start, turn off, back on, off, then start. if you cycle the pump a couple times and it fires right up you'll have a suspect and can confirm with the gauges.
injectors loose pressure overnight but injectors that aren't leaking build and hold pressure in an instant. leaky injectors won't always pressurize on the first crank and can be slow starting
the other cool thing is even if you do have the test pointing at injectors you don't have to replace them all. you can send yours in for cleaning and a flow bench test where they can identify which injector is the problem.
injectors loose pressure overnight but injectors that aren't leaking build and hold pressure in an instant. leaky injectors won't always pressurize on the first crank and can be slow starting
the other cool thing is even if you do have the test pointing at injectors you don't have to replace them all. you can send yours in for cleaning and a flow bench test where they can identify which injector is the problem.
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Thread Starter
Drifting
Joined: Oct 2008
Posts: 1,793
Likes: 63
From: Staten Island/NJ NY/NJ
Thread Starter
Drifting
Joined: Oct 2008
Posts: 1,793
Likes: 63
From: Staten Island/NJ NY/NJ
ok so I got the fuel pressure gauge on it. let it sit. the first time u turn and it starts harder (but not as hard as it has) the gauge builds pressure slowly. then turn it off turn it back on it builds pressure much faster.
got a DELCO fuel filter on the way gonna swap that anyway cause 11 years on a fuel filter on a car that only had 12,800
will keep you updated
got a DELCO fuel filter on the way gonna swap that anyway cause 11 years on a fuel filter on a car that only had 12,800
will keep you updated
Thread Starter
Drifting
Joined: Oct 2008
Posts: 1,793
Likes: 63
From: Staten Island/NJ NY/NJ
okay so changed the fuel filter and the air intake filter (unrelated) and cleaned the TB.
Still does the hard start with the gradual fuel pressure build but on 2nd crank it builds it much quicker.
what am I dealing with here? FP going bad? FP clogged? we dont think its the injector O-rings but it could be. we hooked the gauge up to the drivers side fuel rail adaptor.
when we shut the car down the pressure would drop to 0 is that correct??
Still does the hard start with the gradual fuel pressure build but on 2nd crank it builds it much quicker.
what am I dealing with here? FP going bad? FP clogged? we dont think its the injector O-rings but it could be. we hooked the gauge up to the drivers side fuel rail adaptor.
when we shut the car down the pressure would drop to 0 is that correct??
Thread Starter
Drifting
Joined: Oct 2008
Posts: 1,793
Likes: 63
From: Staten Island/NJ NY/NJ
also...
bought the column lock bypass module did not install it yet. is it possible the signal is fkd up coming from the column lock and not letting fuel pump to the motor right away??
Burning Brakes
Joined: Mar 2013
Posts: 1,131
Likes: 5
From: Illinois/Wisconsin Line
You also have to check it when its Hot and fully warmed up. I think you can unplug each Injector 1 by 1 to get to the ones that r bad but If they r leaking Try getting Injector Cleaner before replacing em all. It does work about 60 % of the time. GM will not replace an Injector under warranty until a Tech tries cleaning it first. At least thats the way it was several yrs ago.
The can of cleaner is nice to do Every yr. You disconnect the lines coming from the tank and the motor runs on the can at about 2500rpm until the hole can is used but it only works if some crap got in there anything smaller than a grain of fine salt will do it, but if the internal injector seals are rotted or damaged by corn in ur fuel. IE Alcohol Its done
Another thing is sometimes the problem is the gas winter additives or winter blend All gas staions do it and some get it into spring/Summer and in the Higher temps above 60 degrees causes alot of seal swelling. So it maybe just ur Fuel Try running all the gas up and go to a Shell or Mobil Station and see if it does O.K. AND DONT EVER GET GAS AT A sTATION THAT HAS A tANKER TRUCK THERE FILLING UP THE GAS STAION TANKS.
It stirs up all the crap when filling them up from the bottom and takes hrs to settle
The can of cleaner is nice to do Every yr. You disconnect the lines coming from the tank and the motor runs on the can at about 2500rpm until the hole can is used but it only works if some crap got in there anything smaller than a grain of fine salt will do it, but if the internal injector seals are rotted or damaged by corn in ur fuel. IE Alcohol Its done
Another thing is sometimes the problem is the gas winter additives or winter blend All gas staions do it and some get it into spring/Summer and in the Higher temps above 60 degrees causes alot of seal swelling. So it maybe just ur Fuel Try running all the gas up and go to a Shell or Mobil Station and see if it does O.K. AND DONT EVER GET GAS AT A sTATION THAT HAS A tANKER TRUCK THERE FILLING UP THE GAS STAION TANKS.
It stirs up all the crap when filling them up from the bottom and takes hrs to settle
Last edited by cudamax; Jun 8, 2013 at 04:12 PM.
Thread Starter
Drifting
Joined: Oct 2008
Posts: 1,793
Likes: 63
From: Staten Island/NJ NY/NJ
You also have to check it when its Hot and fully warmed up. I think you can unplug each Injector 1 by 1 to get to the ones that r bad but If they r leaking Try getting Injector Cleaner before replacing em all. It does work about 60 % of the time. GM will not replace an Injector under warranty until a Tech tries cleaning it first. At least thats the way it was several yrs ago.
The can of cleaner is nice to do Every yr. You disconnect the lines coming from the tank and the motor runs on the can at about 2500rpm until the hole can is used but it only works if some crap got in there anything smaller than a grain of fine salt will do it, but if the internal injector seals are rotted or damaged by corn in ur fuel. IE Alcohol Its done
Another thing is sometimes the problem is the gas winter additives or winter blend All gas staions do it and some get it into spring/Summer and in the Higher temps above 60 degrees causes alot of seal swelling. So it maybe just ur Fuel Try running all the gas up and go to a Shell or Mobil Station and see if it does O.K. AND DONT EVER GET GAS AT A sTATION THAT HAS A tANKER TRUCK THERE FILLING UP THE GAS STAION TANKS.
It stirs up all the crap when filling them up from the bottom and takes hrs to settle
The can of cleaner is nice to do Every yr. You disconnect the lines coming from the tank and the motor runs on the can at about 2500rpm until the hole can is used but it only works if some crap got in there anything smaller than a grain of fine salt will do it, but if the internal injector seals are rotted or damaged by corn in ur fuel. IE Alcohol Its done
Another thing is sometimes the problem is the gas winter additives or winter blend All gas staions do it and some get it into spring/Summer and in the Higher temps above 60 degrees causes alot of seal swelling. So it maybe just ur Fuel Try running all the gas up and go to a Shell or Mobil Station and see if it does O.K. AND DONT EVER GET GAS AT A sTATION THAT HAS A tANKER TRUCK THERE FILLING UP THE GAS STAION TANKS.
It stirs up all the crap when filling them up from the bottom and takes hrs to settle
the car was warm wen we did the test.
if I unplug one injector at a time how would that diagnose it? because the injector wouldn't be doing anything ? so it wouldn't allow the leak of pressure ? so the gauge would hold pressure?
Burning Brakes
Joined: Mar 2013
Posts: 1,131
Likes: 5
From: Illinois/Wisconsin Line
You got it. When u disconnect one injectors power to pulse It shouldnt bleed down as much on ur Gauge
The best way is to disconnect all of them and connect 1 by 1 checking for presure drop ON EACH 1.
http://www.youfixcars.com/testing-fuel-injectors.html
cHECK THE INTERNET YOU'LL FIND ALOT ON CHECKING PRESURE ON GM INJECTORS
The best way is to disconnect all of them and connect 1 by 1 checking for presure drop ON EACH 1.
http://www.youfixcars.com/testing-fuel-injectors.html
cHECK THE INTERNET YOU'LL FIND ALOT ON CHECKING PRESURE ON GM INJECTORS
Last edited by cudamax; Jun 8, 2013 at 05:11 PM.
Thread Starter
Drifting
Joined: Oct 2008
Posts: 1,793
Likes: 63
From: Staten Island/NJ NY/NJ
disconnect plug start it shut it. see if it bleeds down slower.
then reconnect and move down the line until i get to one that seems screwy?
then just replace that one?
Burning Brakes
Joined: Mar 2013
Posts: 1,131
Likes: 5
From: Illinois/Wisconsin Line
Their is alot on this forum too Everything u need even in the C4 section
http://forums.corvetteforum.com/c4-t...do-i-test.html
http://forums.corvetteforum.com/c4-t...do-i-test.html
Burning Brakes
Joined: Mar 2013
Posts: 1,131
Likes: 5
From: Illinois/Wisconsin Line