fuel injection question
#1
Member
Thread Starter
Join Date: Apr 2003
Location: USA
Posts: 24
Upvotes: 0
Received 0 Upvotes
on
0 Posts
fuel injection question
Hey guys!
I have a problem with a 92 Lumina Sedan 3.1 multi port fuel injected when you try to start this car it just cranks if I floor it I can get it started then it backfires and black smoke poors out I saw that the throttle body was dumping out gas.
I assume it might be a leaking injector I took it to a garage and they had it two days but say they cant find anything ( I have no confidence in any of the garages around here) I took it to the garage because I dont have a way to check the injectors any advice?
I have a problem with a 92 Lumina Sedan 3.1 multi port fuel injected when you try to start this car it just cranks if I floor it I can get it started then it backfires and black smoke poors out I saw that the throttle body was dumping out gas.
I assume it might be a leaking injector I took it to a garage and they had it two days but say they cant find anything ( I have no confidence in any of the garages around here) I took it to the garage because I dont have a way to check the injectors any advice?
#2
Member
Join Date: Apr 2002
Location: Pittsburgh,Pa
Posts: 2,400
Upvotes: 0
Received 0 Upvotes
on
0 Posts
If it's dumping that much fuel remove the upper plenum and pull the fuel rail.Disconnect the electrical connection and crank the engine.Any injector that sprays,squirts or drips fuel is bad.You can do this in less than 1/2 hour if you take your time at it.Then let us know the outcome.
#4
Member
Join Date: Mar 2004
Location: Canada
Posts: 35
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Do a leak down test.
Put a fuel pressure gauge on. Turn the key on and pressurize the system. Turn off the key and clamp off the pressure line along with the return line. Wait and if the needle drops there is a leaking injector.
Put a fuel pressure gauge on. Turn the key on and pressurize the system. Turn off the key and clamp off the pressure line along with the return line. Wait and if the needle drops there is a leaking injector.
#5
Davo is telling you the only way to determine WHICH ONE is leaking. When you pull the fuel rail, the injectors stay with the rail. If they are unplugged, they won't open electrically and if any squirt, they are leaking.
Before doing that, try checking the vacuum line on the regulator for fuel in it and do the rest pressure leakdown test that Warn spoke of. Just remember, it can also leak down back to the tank through the fuel pump so you may have to pinch off both hoses after pressurizing them to be sure it's the injectors leaking.
Before doing that, try checking the vacuum line on the regulator for fuel in it and do the rest pressure leakdown test that Warn spoke of. Just remember, it can also leak down back to the tank through the fuel pump so you may have to pinch off both hoses after pressurizing them to be sure it's the injectors leaking.
#6
uh...
...it HAS to be something leaking at the engine...an injector stuck open or a bad pressure regulator...otherwise he wouldn't have black smoke. fuel coming out of the throttle body sound like a pressure regulator to me...after getting that upper plenum off...slip the vacuum line off of it and turn the key on to see if fuel shoots out of the regulator vacuum nipple...if so, you need one
#7
Re: uh...
Originally posted by carguyinva
...it HAS to be something leaking at the engine...an injector stuck open or a bad pressure regulator...otherwise he wouldn't have black smoke. fuel coming out of the throttle body
...it HAS to be something leaking at the engine...an injector stuck open or a bad pressure regulator...otherwise he wouldn't have black smoke. fuel coming out of the throttle body
#8
a matter of semantics perhaps...
...but i'd be surprised if you could get enough pressure with that gross leak and get clamps on the lines fast enough...fuel is going to go where it goes as soon as the pump runs. if fuel is running out of the throttle body...it's getting into the upper plenum area...the injectors are way down stream of that.
your test procedure is correct tho for isolating leaking injectors...i just believe it's going to be VERY obvious
your test procedure is correct tho for isolating leaking injectors...i just believe it's going to be VERY obvious
#10
Member
Thread Starter
Join Date: Apr 2003
Location: USA
Posts: 24
Upvotes: 0
Received 0 Upvotes
on
0 Posts
you guys have been a big help thanks
I have fuel leaking from the pressure regulator so I going to replace it.
In reply to "I dont even know hows it runs after its started"
this car runs so good even the garage commented on it.
keep in mind it only floods after it has been shut off for 15 min. or more.
I have fuel leaking from the pressure regulator so I going to replace it.
In reply to "I dont even know hows it runs after its started"
this car runs so good even the garage commented on it.
keep in mind it only floods after it has been shut off for 15 min. or more.