fuel system failure

[findlay]

I have a 1988 GL wagon 1.8 L SPFI (EA-82), manual transmission with
4WD. Lately it's been difficult to start up, but once it starts it
runs fine until this week when it finally quit. I don't drive the car
that often these days, so it hasn't been much of a concern, especially
considering how busy I have been with school this semester.

To get the car going I would pour some fuel from a little jug I kept
in the car into the intake manifold and crank it a few times until I
got ignition, but since Tuesday I haven't been able to get that to
work.

All of the components of the secondary ignition system (spark plugs,
spark cables, cap, rotor, even the coil) are relatively new, and I've
verified ignition on all of the cylinders with a timing light. Thus,
I believe that it is a fuel problem. The car has had low fuel
pressure for a few years. I know this because when I replace the fuel
filter it doesn't spew very much at all. I don't know how low it is,
and I don't have any way of measuring it. Back when it was running,
when I started it up it often would have very low horsepower for
several minutes until it got warmed up.

I'm wondering whether the problem is the fuel pump or the fuel
injector or maybe something else. Is there any way to test these
components before going to the junk yard?


Justin

 

[AB]

Air leak between the air flow sensor and the intake manifold??

 

[S]

Hi Justin!

I have a 1988 GL wagon 1.8 L SPFI (EA-82), manual transmission with
4WD. Lately it's been difficult to start up, but once it starts it
runs fine until this week when it finally quit. I don't drive the car
that often these days, so it hasn't been much of a concern, especially
considering how busy I have been with school this semester.

To get the car going I would pour some fuel from a little jug I kept
in the car into the intake manifold and crank it a few times until I
got ignition, but since Tuesday I haven't been able to get that to
work.

All of the components of the secondary ignition system (spark plugs,
spark cables, cap, rotor, even the coil) are relatively new, and I've
verified ignition on all of the cylinders with a timing light. Thus,
I believe that it is a fuel problem. The car has had low fuel
pressure for a few years. I know this because when I replace the fuel
filter it doesn't spew very much at all. I don't know how low it is,
and I don't have any way of measuring it. Back when it was running,
when I started it up it often would have very low horsepower for
several minutes until it got warmed up.

I'm wondering whether the problem is the fuel pump or the fuel
injector or maybe something else. Is there any way to test these
components before going to the junk yard?


Justin

Mmmmm, if you squirt raw fuel into the intake, and crank the starter,
she ought to fire, even if only for a couple revolutions, independent
of whatever the EFI system is or isn't doing.. If this isn't
happening, I'd check the ignition timing and engine compression to see
why not.
Earlier GL's had the fuel pump external to the tank, but I _think_ the
EFI versions had an in-tank pump. In either event, you can put a
pressure gauge (most any 100PSI brass gauge with appropriate fittings
will do) in the line ahead of the injectors (the line between the fire
wall and engine is a good spot), manually powering the fuel pump, and
check for adequate pressure. What's "adequate"? Don't know, I'd think
you'd want to see at least 45PSI or so. Usually, you can also check
the injectors by dismounting then individually, and having someone
work the starter while you watch the injector. Should give a nice even
spray as it fires.
I don't recall if these engines had a "cold-start" injector, or simply
increased the duration of the regular ones for cold start enrichment,
but either way there is a coolant temperature sensor that controls
this function. If it isn't giving the ECU the proper signal, cold
starts will never happen unless you give it a little juice manually as
you've described.
These tests are dangerous, so be careful, OK? Real easy to change a
cool old GL into a torch, not to mention it's owner. Don't go there.
It's really good practice to have someone standing by with a fire
extinguisher just in case.
I might have a paper manual with nfo on the EA-82 EFI system stashed
out in the garage. If you get stuck, drop a line and I'll see if I
can't find it, scan the appropriate pages and send 'em along.
Good luck, and again, BE CAREFUL!
ByeBye! S.
Steve Jernigan KG0MB
Laboratory Manager
Microelectronics Research
University of Colorado
(719) 262-3101

 

[johninky]

This model has just one large injector. The fuel pump is external and
located in front of the RR wheel. Fuel pressure runs between 30 and
40 lbs. The system uses a CTS, coolant temperature sensor, to assist
cold starts. The ECU uses the coolant temperature to know whether the
engine is cold or hot. If cold, then it increases the injector
pulse. Sort of performs the same function as a choke. But as Steve
pointed out, the engine should have fired when gasoline was added
through the intake manifold.

May want to try a shot of starting fluid. Just a small amount because
too much and it can blow a hole in a piston.

When cranking the engine you should be able to see fuel being sprayed
by the injector. Have to remove the air intake plumbing.

If you know for a fact the engine has good spark I would clean the CTS
and if that accomplished nothing, would replace the entire throttle
body with another from a wrecking yard. These things used cost next
to nothing.

 

[nobody >]

S wrote:

(Steve, rearranged your post just a little..)

These tests are dangerous, so be careful, OK? Real easy to change a
cool old GL into a torch, not to mention it's owner. Don't go there.
It's really good practice to have someone standing by with a fire
extinguisher just in case.

Usually, you can also check
the injectors by dismounting then individually, and having someone
work the starter while you watch the injector. Should give a nice even
spray as it fires.

Gasoline injectors aren't as bad as diesel ones (those can actually cut
a finger off), but don't put any body parts in front of the injector
nozzle.

The injector can force gasoline thru the skin, similar to those "jet
needles' used for vaccinations. It's not an "instant death" item, but it
can be extremely hazardous to your health.

If you need something to check for spray, aim it at a small piece of
smooth cardboard.

As Steve said, this one's dangerous.

 

[johninky]

Had another thought about this. What if the problem is too much
fuel? This would explain why adding fuel didn't work. Attempt to
start the engine and then pull a spark plug. Wet plug means the
engine is flooded. Had a GM car once that did this.

 

[johninky]

Any progress made?

The no-start condition could also be timing belt related. Sometimes
the timing belt will shred before breaking and throw the timing way
off. Had it happen once.

 

[1 Lucky Texan]

Any progress made?

The no-start condition could also be timing belt related.  Sometimes
the timing belt will shred before breaking and throw the timing way
off.  Had it happen once.

Holding a strip of paper at the tailpipe while someone cranks the
engine might indicate if the TB has slipped. The paper will try to
suck IN to the pipe.

 

[findlay]

Sorry for getting back so late. Finals are finally over. Yes, there
is only one fuel injector and it sits in the center of the throttle
body just above the butterfly plate, and the fuel pump is external.
No, the intake is in good condition, appears to have no leaks. The
car will chug for a few revolutions after I've dumped a little fuel in
before running out. Sometimes only two cylinders will fire because
the car is not on a level surface and the fuel will drain to one
side. Usually it helps for me to wait a few minutes for the fuel to
evaporate inside the intake manifold and combustion chambers.

I'm confident the timing is good because I changed the timing belts
about 3 years/15,000 miles ago. Today I finally got around to looking
at it again. After cranking it a couple of times I opened up the
throttle and gently pulled the fuel injector out with some channel
lock pliers. The fuel rail comes in into the side of the throttle and
through a little hole in the side of the injector. When I pulled out
the injector, pressure from the fuel supply rail spewed a significant
amount into the throttle chamber. It looks like I'm going to the junk
yard this week. Fuel injectors are $7 there, but $500 at autozone,
which happens to be the amount I paid for the car 5 years ago.


Justin

 

[findlay]

I put in a junkyard fuel injector today and the car runs like new,
except that it's burning coolant, but that's a long story.


Justin

 

[findlay]

I put in a junkyard fuel injector today and the car runs like new,
except that it's burning coolant, but that's a long story.

Well, that was yesterday, but now I'm stuck with the same problem
again. I'm not getting any computer codes, so my best guess is that
it has to be the computer itself.

 

[1 Lucky Texan]

Well, that was yesterday, but now I'm stuck with the same problem
again.  I'm not getting any computer codes, so my best guess is that
it has to be the computer itself.

just a crazy idea, is there fuel pressure regulater maybe on the end
of the 'rail' or somehwere? maybe it's stuck open or compromised
somehow.

Weird how it seemed to work after your repair - that could be a clue.