OK...Need C4 help.
Thread Starter
Burning Brakes
Joined: Apr 2005
Posts: 1,227
Likes: 0
From: Atlanta Ga
OK...Need C4 help.
I have an 86 fuel injection system in my C3 thats been converted to speed density. It has ran PERFECT until tonight. On the way home tonight she just shut down (ended up flat bedded home)
Heres what i have discovered.
Fuel pump is running, but not sure how much PSI yet.
Engine is severely flooding...To the point of LOTS of raw fuel is leaking out of the exhaust pipe joint where the cat use to be. Even the collector area of the manifolds (81/82 corvette style) is wet with fuel.
I held pedal to floor once to shut off injectors and clear lines. It did run for few secs before it choked out.
My ??? is..where should i begin. Regulator? if it breaks/Sticks it wouldnt cause this kind of flooding would it?
What about the injectors...surely they wouldnt be stuck to allow this kind of flooding.
Would low pump pressure cause flooding since veh wouldnt crank.
which direction would you go.
Now heres a kicker. about 2 hours earlier i put a pretty strong concentration of SEAFOAM injector cleaner. Think this could have caused the issue?
Im gonna get a good nights rest and tomorrow morning im at it. Im hoping a golden trail of ideas and tech info will be here by 8am est
Heres what i have discovered.
Fuel pump is running, but not sure how much PSI yet.
Engine is severely flooding...To the point of LOTS of raw fuel is leaking out of the exhaust pipe joint where the cat use to be. Even the collector area of the manifolds (81/82 corvette style) is wet with fuel.
I held pedal to floor once to shut off injectors and clear lines. It did run for few secs before it choked out.
My ??? is..where should i begin. Regulator? if it breaks/Sticks it wouldnt cause this kind of flooding would it?
What about the injectors...surely they wouldnt be stuck to allow this kind of flooding.
Would low pump pressure cause flooding since veh wouldnt crank.
which direction would you go.
Now heres a kicker. about 2 hours earlier i put a pretty strong concentration of SEAFOAM injector cleaner. Think this could have caused the issue?
Im gonna get a good nights rest and tomorrow morning im at it. Im hoping a golden trail of ideas and tech info will be here by 8am est
Team Owner
Joined: Sep 2001
Posts: 62,143
Likes: 1,729
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
It almost sounds as if the injectors are all stuck open or the plugs are completely fouled.
I think I'd start by checking fuel pressures at the rail, while running and note what the pressure does immediately after shutdown.
I think I'd start by checking fuel pressures at the rail, while running and note what the pressure does immediately after shutdown.
Thread Starter
Burning Brakes
Joined: Apr 2005
Posts: 1,227
Likes: 0
From: Atlanta Ga
you know thats exactly what i was wondering, but man how in the world could all the injectors go bac at same time. Surely the seafoam cleaner couldnt/wouldnt cause this
What sensor (TPS) controls the injectors fiiring wide open.??
What sensor (TPS) controls the injectors fiiring wide open.??
Racer
Joined: Nov 2004
Posts: 445
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[QUOTE=JustForFun]you know thats exactly what i was wondering, but man how in the world could all the injectors go bac at same time. Surely the seafoam cleaner couldnt/wouldnt cause this
Don't know about Seafoam...Do know about ONE injector being stuck open enough that when I pulled the dipstick it had a strong fuel smell.
I suggest you check the oil before attempting to start again.
Mine happened after a rebuild, and all injectors being cleaned and checked. Turns out I did two oil changes before the car moved an inch...!
With a fp gauge connected turn ig. on for a few sec's, turn ig. off and watch the needle drop...if a stuck inj. is the problem.
Don't know about Seafoam...Do know about ONE injector being stuck open enough that when I pulled the dipstick it had a strong fuel smell.
I suggest you check the oil before attempting to start again.
Mine happened after a rebuild, and all injectors being cleaned and checked. Turns out I did two oil changes before the car moved an inch...!
With a fp gauge connected turn ig. on for a few sec's, turn ig. off and watch the needle drop...if a stuck inj. is the problem.
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Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
I would do as suggested and get a fuel pressure guage on and check the pressure when the pump primes, when the engine is running, and after shutdown for a quick drop in pressure. You need to also check the viscosity/smell of the oil because it probably has gas in it and needs to be changed. You can pull the vacuum off the FPR and look for gas inside. You wouldn't think all the injectors would be stuck open, but I've heard of stranger things happen. You can also ohm the injectors one at a time hot and cold and should be around 16 ohm +/- a ohm or two.
good point.
Thread Starter
Burning Brakes
Joined: Apr 2005
Posts: 1,227
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From: Atlanta Ga
heres what ive4 found thus far.
41lbs of psi during intial key on.
crank engine pressure drops to 35lbs
turn car off and pressure slowly bleeds to zero
crank car while pressure is fallinjg and psi is around 20
hold pedal to floor and crank engine 0-5 psi
41lbs of psi during intial key on.
crank engine pressure drops to 35lbs
turn car off and pressure slowly bleeds to zero
crank car while pressure is fallinjg and psi is around 20
hold pedal to floor and crank engine 0-5 psi
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Originally Posted by JustForFun
heres what ive4 found thus far.
41lbs of psi during intial key on.
crank engine pressure drops to 35lbs
turn car off and pressure slowly bleeds to zero
crank car while pressure is fallinjg and psi is around 20
hold pedal to floor and crank engine 0-5 psi
41lbs of psi during intial key on.
crank engine pressure drops to 35lbs
turn car off and pressure slowly bleeds to zero
crank car while pressure is fallinjg and psi is around 20
hold pedal to floor and crank engine 0-5 psi
How long did it take for the pressure to bleed down to zero? If less than 30 minutes you have leaking injectors, blown diaghram in FPR, or check valve not holding. Since the is evidence of gas in the exhaust I believe you will have leaking injectors.
15 sec is mighty quick. If you checked the vacuum on the FPR for fuel inside and didn't find any I am going to say you are in need of new injectors ($200-$250/set).
Thread Starter
Burning Brakes
Joined: Apr 2005
Posts: 1,227
Likes: 0
From: Atlanta Ga
latest....
Now when turning on the key, the fuel PSI is about 20 as soon as the pump stops priming it falls to zero.
couple of times i heard a click under the hood, like a injector ckicking and when i turned the key pump psi went to 45 and held at 30 after prime.
Now when turning on the key, the fuel PSI is about 20 as soon as the pump stops priming it falls to zero.
couple of times i heard a click under the hood, like a injector ckicking and when i turned the key pump psi went to 45 and held at 30 after prime.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Originally Posted by JustForFun
latest....
Now when turning on the key, the fuel PSI is about 20 as soon as the pump stops priming it falls to zero.
couple of times i heard a click under the hood, like a injector ckicking and when i turned the key pump psi went to 45 and held at 30 after prime.
Now when turning on the key, the fuel PSI is about 20 as soon as the pump stops priming it falls to zero.
couple of times i heard a click under the hood, like a injector ckicking and when i turned the key pump psi went to 45 and held at 30 after prime.
Team Owner
Joined: Sep 2001
Posts: 62,143
Likes: 1,729
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
I would just go ahead and replace it all, injectors and FPR, if i had the money.
A new Holley adjustable regulator and new Ford injectors, and I dont think i'd ever be using Seafoam again.
A new Holley adjustable regulator and new Ford injectors, and I dont think i'd ever be using Seafoam again.
Thread Starter
Burning Brakes
Joined: Apr 2005
Posts: 1,227
Likes: 0
From: Atlanta Ga
Originally Posted by vader86
I would just go ahead and replace it all, injectors and FPR, if i had the money.
A new Holley adjustable regulator and new Ford injectors, and I dont think i'd ever be using Seafoam again.
A new Holley adjustable regulator and new Ford injectors, and I dont think i'd ever be using Seafoam again.