Corvette Forum : DigitalCorvettes.com Corvette Forums banner

1 - 20 of 24 Posts

·
Registered
Joined
·
267 Posts
Discussion Starter #1
hi guys fortune definatly left me...had the trans rebuild but the car was stranded at the shop during the summer,no time for fun during the summer for me, i have a bar on the beach only lot of work...after 9 months had the car at home again,new 700r4 with some goodies on it...you know the beast,boost valve .50,wider band,had new headmann too and a paint job at the body shop,the day after i try to fire up my baby and she goes complitely flooded,removed all the plugs totaly wet,dryed cylinders blowing air trough plugs holes with my compressor,fire it up again,this time engine starts but a bad white smoke choked me...probably the guy at the shop messed with TPS,FP regulator not knowing what he was doing.... you know .54 volts at TPS using a voltmeter...:crazy: probably just a screw driver using his ear,the same for fuel pressure... a couple of turn at the screw...a pressure gauge at the rail? what is it for:thud:,but i'm worry may be leaking injectors due to long period stop,but every cylinders are plenty of gasoline i don't think all eight injectors goes bad at the same time after 2000 miles ... sorry i was too long... any idea
 

·
Premium Member
Joined
·
2,106 Posts
flooding on initial start is usually due to bad or disconnected temp sensor on front of engine.

What year?

The pressure regulator on fuel rail won't cause it to flood. unlikely you can get that much pressure from your system..
 

·
Registered
Joined
·
267 Posts
Discussion Starter #4
i dryed again all cylinders,dryed plugs too and wont'start,flooded again, but i noticed a fssssss-noise coming at fuel pump priming,it's like fuel drain out from fuel rail...i need first a gauge pressure test at the rail,may be pressure drop due to a leaking injectors,the noise is clear something is appening in fuel rail,i never heard this noise,just pump running noise

1)pump run in on and pump relais click
2)engine crank but don't start
3)after 2 attempts it's flooded,smell of gasoline unburned all around

Injectors are new,it had new ignition module,new cap/coil,new rotor,new IAC valve.

I'll try again with ceck list lots of thing may go wrong...but car run fine before entry the shop...yes she was stranded there for 9 months,from May,but what happend...
 

·
Registered
Joined
·
1,855 Posts
i noticed a fssssss-noise coming at fuel pump priming,it's like fuel drain out from fuel rail...
Maybe the cold start injector is leaking? ( not uncommon with age )
CSI is only supposed to spray when cranking cold engine.
If faulty it may be spraying fuel full time
Only real way to test on car is to disconnect the steel line to injector and cap the port feeding it at the rail so it gets no fuel.
 

·
Registered
Joined
·
267 Posts
Discussion Starter #6
Maybe the cold start injector is leaking? ( not uncommon with age )
CSI is only supposed to spray when cranking cold engine.
If faulty it may be spraying fuel full time
Only real way to test on car is to disconnect the steel line to injector and cap the port feeding it at the rail so it gets no fuel.
after one attempt the car is flooded,this is not a normal condition,a leaking CSI may be,but if I disconnect csi line and cap it at rail,without csi it don't start as well...:huh:
 

·
Registered
Joined
·
1,855 Posts
if I disconnect csi line and cap it at rail,without csi it don't start as well...:huh:
Worst case it takes a little longer to crank before firing
Idea was to prove if the CSI is leaking.
 

·
Registered
Joined
·
267 Posts
Discussion Starter #9
thanks guys i'll try all your advices,i hope to fix soon :thumbsup:
 

·
Registered
Joined
·
724 Posts
Unplug the mass air flow sensor - fire it up...and see if it runs.

It won't run well, but should at least run and not has as much smoke.

I'd put my money on that.
What exactly will this tell OP? Why do this if no DTC 34??? Is this even is diagnostic sequence for 34?

If he gets it running "not well", as you say, what does he do next?
 

·
Registered
Joined
·
267 Posts
Discussion Starter #11
totaly flooded again ,no way it fire up.i have unpluged all the plugs and wiped it and dryed blowing air into cylinders so many time i don't remember and now i can't look the engine bay anymore...:thud:today a take a pressure gauge from my shop guy and try to ceck again for pressure drops-leaking inj,correct spark-ignition module,timing ecc.
 

·
Registered
Joined
·
267 Posts
Discussion Starter #12
just a little better,unplugged CSI,dryed all cylinder, had set TPS to a perfect 0.54 volts,this time she fired up ,warmed up an take a little ride,much better but not enough,some backfire come in ,but i'm in the right way,not tested fuel pressure with a gauge, next ceck to do, car run very rich,probably to much pressure at regulator,had new 24 lb/h injs but prom not tuned for larger injectors...hope to have again on the road as soon as possible...:D

Thanks Vetteoz probably the CSI goes wrong,unplugged and engine fired up,some other test when i have a pressure gauge...
 

·
Registered
Joined
·
267 Posts
Discussion Starter #13
Today i had a fuel pressure test at rails,priming the pump, key in on, had 41-42 psi,but it drops in 2 minutes @ 30 psi, after 15 minutes had 20-19 psi,after 30 minutes had 10 PSI.Is it a normal pressure drop?If this pressure may be considered steady,then i exclude any leak issue,so why engine goes flooded,may be a ignition issue?bad firing at the plugs and fuel accumulates into clylinders...Inspected distributor,that had new ignition module ,cap/coil and rotor(Hey large cap dist),everything is in good condition,clean and dry, terminal at rotor is very clean,but try forcing a little bit the rotor i find a lash,is this normal?or this is a worn distributor gear evidence?May be too much retarded?,i lost the timing tab at dumper...at the moment i can't ceck timing with my inductive light gun:thud: sorry guys i know my 2011 starts good
 

·
Premium Member
Joined
·
2,106 Posts
Today i had a fuel pressure test at rails,priming the pump, key in on, had 41-42 psi,but it drops in 2 minutes @ 30 psi, after 15 minutes had 20-19 psi,after 30 minutes had 10 PSI.Is it a normal pressure drop?If this pressure may be considered steady,then i exclude any leak issue,so why engine goes flooded,may be a ignition issue?bad firing at the plugs and fuel accumulates into clylinders...Inspected distributor,that had new ignition module ,cap/coil and rotor(Hey large cap dist),everything is in good condition,clean and dry, terminal at rotor is very clean,but try forcing a little bit the rotor i find a lash,is this normal?or this is a worn distributor gear evidence?May be too much retarded?,i lost the timing tab at dumper...at the moment i can't ceck timing with my inductive light gun:thud: sorry guys i know my 2011 starts good

NOt sure what the book says.. but what you have isn't bad. You should hold the inital 40 a little longer but again.. not bad.
I wouldn't worry about pressure being your issue at this time.

Have you been able to test your temperature sensor? this isn't the same thing that sends a signal to your dash. it is a separate sensor on the front of your block and you need a scan tool to tell what it's reading.


a little lash in the dist is ok-- defined as maybe 1/16 to 1/8 inch play.. again not optimum but it would only cause a slight miss , bad mileage and a loss of upper end power. if your base idle is way out of specs then it wouldn't run or would run barely or with a super high idle-- it wouldn't cause flooding.
 

·
Registered
Joined
·
1,523 Posts
I'd look into the Temp sensor. Basically what this sensor does is tell the ECU what the temp is based on a voltage scale that increases/decreases with tempature, and the ECU will enrich for cold start and lean out as the temp increases. In sense this is the choke for a fuel injected engine. You can test without special tools but they make the job easier. I'll be out later tonight but when I get back I'll tell you the procedure of how to test and the specifications of sensor output.
 

·
Registered
Joined
·
267 Posts
Discussion Starter #16
Thanks 72sbvette i want to ceck CS thermo switch in the front,i have a digital voltmeter ,i hope this works,let me know something,thanks guy
 

·
Registered
Joined
·
1,855 Posts
Thanks 72sbvette i want to ceck CS thermo switch in the front,i have a digital voltmeter
72sbvette was talking about the coolant temperature switch ( CTS ) that send temp reference to the the ECM
Should meter out as below

Engine Coolant Temperature Sensor.
185 Ohms @ 210F,
3400 Ohms @ 68F,
7,500 Ohms @ 39 F.

Most common problem with Cold start thermo switch is it not closing and operating the CSI as it should.
As it is only powered up when cranking engine impossible for it to be activating CSI full time
If fuel coming from CSI when it shouldn't then injector is leaking
 

·
Registered
Joined
·
267 Posts
Discussion Starter #18
i had a 7,200 reading at CTS yesterday when i ceck it with my voltmeter,and it was coherent with outside temperature...my injectors are new,only 3000 miles on it ,i can belive i had to remove all that stuffs only to test for a leak...:thud:,Vetteoz what do you think about my pressure drops VS minutes i had reported?
pressure test

had 41-42 psi,but it drops in 2 minutes @ 30 psi, after 15 minutes had 20-19 psi,after 30 minutes had 10 PSI.

Is this a steady pressure,or a dropping pressure?
 

·
Premium Member
Joined
·
2,106 Posts
i had a 7,200 reading at CTS yesterday when i ceck it with my voltmeter,and it was coherent with outside temperature...my injectors are new,only 3000 miles on it ,i can belive i had to remove all that stuffs only to test for a leak...:thud:,Vetteoz what do you think about my pressure drops VS minutes i had reported?
pressure test

had 41-42 psi,but it drops in 2 minutes @ 30 psi, after 15 minutes had 20-19 psi,after 30 minutes had 10 PSI.

Is this a steady pressure,or a dropping pressure?
the temp sensor on the front of the engine is relative to engine operating temps not outside air temps. if your readings are high ohms your car is thinking it needs a lot of fuel. Did you check at the sensor or the wire at the ECM? check the sensor readings and then check the ECM wire readings at the connector. if there is a broken wire you'll get high OHMS and the car will flood.

Have you tried starting it with the CSI and MAF disconnected electrically?
 

·
Registered
Joined
·
267 Posts
Discussion Starter #20
the temp sensor on the front of the engine is relative to engine operating temps not outside air temps.
Have you tried starting it with the CSI and MAF disconnected electrically?
Yes BLKvette94 I know that sensor monitoring engine temperature...i tried in both way, engine fired just one time with MAF on and CSI off,after dried all cylinders by compress air...Car run and warmed,relatively good idle (had TPS cecked at 0,54 volts),runs very rich smelling in gasoline all around and a lot of smoke,but it stays at idle ,during the day i have fired engine 3-4 times and let it warm,the day after nothing flooded again at first attempt.
 
1 - 20 of 24 Posts
Top