90 spirit won't run

I have a problem with my 1990 Dodge Spirit (2.5L non-turbo) that fires, but
won't run. To keep it running, I have to pump the gas fairly fast. When I
press the gas pedal, it accellerates for about a second, then it will stall if
I don't pump it again. I originally thought it was the AIS, so I replaced that.
That didn't work. I remembered the trick for the self-diagnostic and did
that. Originally, the self-diagnostic came up with codes 12, 15 and 24. One
was "Battery was recently disconnected", one was "TPS reads over 4.96V", and
the other was "Speed/Distance sensor wasn't receiving a signal". I went back
to work on it today, disconnected the battery, started the car (pumping the
gas) and kept it running for a little while and re-checked the diagnostic
codes. Nothing. I replaced the TPS sensor anyways and nothing. It's getting
spark and it's getting gas. The only thing I can think of is it's something
electrical. I parked it wednesday morning, and it ran fine. Wednesday night,
I went to go home, and it wouldn't start.
Any ideas?
TIA
Wes

 

Yup,

Open circuit on the ground leg of the TPS.

 

I'll check for this tomorrow. Thanks for the tip.
I just found some more things to check tomorrow if this doesn't work.
Thanks,
Wes

 

If you are still getting the fault for the TPS sensor, or the vehicle speed
sensor, that could be the problem, check all grounds for the TPS circuit,
if the Vehicle speed sensor is faulty and telling the PCM that it is going
114 miles an hr or more it will cause a no start or shut down, also, if
possible, check fuel pressure when the problem is occuring.
Glenn Beasley
Chrysler Tech

 

The TPS fault code isn't coming up since I disconnected the battery. I even
kept it running until it warmed up, but the only fault code that comes up is
code 12 ("Battery was recently disconnected") and code 55 ("End of Fault
Codes").
Wes

 

Alright - here's an update. We checked the resistance to the ECM from the
speed sensor, TPS, AIS, and fuel injector cap. The only thing with a
noticeable resistance was the ground from the fuel injector cap, which read
between 9 and 10 ohms. I was able to keep the car idling using starting fluid.
While it was idling, the hot wire going to the fuel injector cap was reading a
steady 14V.
From this info, I have a few questions.
1. I assume I should replace the ground wire from the fuel injector cap - 9
ohms is way too high.
2. Is the 14V for the injector cap within reason?
3. Is there anything else it could be besides the fuel pressure or the
injector itself? I'm checking to see if I can get my hands on a fuel pressure
guage tonight.
Thanks,
Wes

 

There is no ground from the fuel injector.
One terminal of the injector is fed constant12 volts (14ish with
engine running), the other terminal is pulled to ground thru the
ECM.
9 ohms is meaningless, a voltage drop would be a more meaningful
measurement. Tough to do without an oscilloscope though...

14 volts is nominal when the engine is running and the alternator
is functioning correctly.

You haven't checked fuel pressure and volume yet?

 

Alright - I took a look at it again last night. Fuel Pressure was reading a
steady ~14 PSI which should be fine (14.5 is what the manual said). I
looked down the throttle body while my brother cranked it over last night
and I think I found the problem. Fuel is injected when it's cranking and
when you first step on the gas pedal. It does NOT continue to inject when
it idles or while you hold the gas down. I don't have an oscilloscope, but
my multimeter showed a constant 14V at the fuel injector, so it should be
injecting fuel. I called the local dodge dealer, and the technician said it
sounded like the fuel pressure regulator. I guess I'll replace that tonight
and see if that fixes it.
Any other suggestions on what it could be?
Thanks,
Wes

 

Is there a way to test the fuel pressure regulator? When I tested the fuel
pressure, I pinched off the return line, and the pressure (on the intake)
did increase.
Wes

 

ok first of all you only have 3 seconds of spark and fuel, if the engine
does not start within that time frame it shuts both off untill restarted
again,second, if you push on the gas pedal while cranking the engine, this
could cut the fuel off if you pump it., it sounds as if you have fuel
pressure and the regulator is doing its job properly.If you see fuel
spraying as you crank it and it does not start you have some other problem,
if you have spark and fuel, you need to check the timing belt for proper
settings, If you e mail me back i wont get your message for awhile, i just
read the ones you sent me a few days ago, post here and i will try to help
you out, o yes, if you keep trying to start the engine, the injectors spray
fuel in the cylinders, this could also cause a flooded condition and make
the engine a no start

 

The car starts, but immediately dies if I don't keep pumping the gas. I
noticed something else last night. The engine seems to bog down for a
fraction of a second when the gas is first injected. If I remember
correctly, it didn't accelerate until the gas was no longer being injected.
Then it dies if I don't pump the gas again. No dark smoke like it's too
rich.
Thanks
Wes

 

Assuming that you are not losing spark, the fuel pressure is maintaining 14
psi........ then you may have a faulty fuel injector, was there an injector
circuit fault found at one time, i think it would be a code 26 but not sure?

 

The spark became less frequent as the car died, but it kept sparking until
it was dead. I assumed the spark was slowing down because the car was dying
(since it wasn't getting gas). There was no fault code for the fuel
injector - just the TPS and the Speed Distance sensor. I ended up replacing
the TPS because of the fault code, but then I went back and tested the
original and it tested fine. I also tested the speed\distance sensor and it
tested OK (8 spots of 8 ohms and infinity between). After I disconnected
and reconnected the battery, I have yet to come up with a fault code besides
12 and 55. If the fuel injector is bad, how could it inject while cranking
and when you first press the gas pedal?
Wes

 

Well, yeah, that would be a definite problem...how did you determine this?
If it was idling, it was running. If it was running, the injector was
injecting fuel.

A digital multimeter wouldn't be fast enough to keep up with the voltage
pulses to the injector, so we can't really draw too much of a conclusion
from this.

No, if you were reading ~14 pounds' pressure at the fuel rail near the
injector, it's not the fuel pressure regulator. The regulator is not
turned on and off; it works or it doesn't. If it sticks open, there'll be
very low (or no) fuel pressure when cranking OR running. If it sticks
closed, there'll be very high fuel pressure when cranking OR running. If
it works, there'll be 14.5psi or so when cranking OR running.

I think you have an electrical problem. Somehow, that injector isn't being
given the right signals.

Another hint: Dealer techs absolutely hate it when do-it-yerselfers call
up and ask for diagnostic help over the phone. Many of them are not above
sending such callers on wild goose chases, and I'm not entirely sure I can
blame them, for such calls amount to unfair demands that they work for
$0.00/hr.

DS

 

OK, it wasn't injecting while it's supposed to be idling. It stops
injecting when you stop cranking. It fires, then decelerates until it dies.
Likewise, it injects when I first press on the gas pedal (the engine
actually bogs down for a second while it's injecting), then it accelereates
for a second, then it decelerates until it dies.

I've checked the TPS, replaced the AIS, checked the Speed/Distance sensor.
What other electrical sensors/relays, etc... do I need to check? The ASD
relay shuts off the ignition, doesn't it? So it shouldn't be that.

When depressurizing the fuel system, the chiltons says to ground one
terminal of the fuel injector, and touch the other terminal to the positive
battery terminal. I assume that's just pumping out any gas that's in there.
Can I bypass the computer for the fuel injector and do the same thing and
make sure it sprays every time the circuit is completed? That should tell
me if the injector's OK, shouldn't it?

Thanks for the info,
Wes

 

If the fuel injector is bad, how could it inject while cranking
and when you first press the gas pedal?
just because you see a spray does not mean it is enough to keep the engine
running, maybe the pintel is not opening enough to let fuel out, i cant
answer that, if you had some gum cutter or similar fluid, would you be able
to keep the engine running that way? and do you have a fuel pressure gauge
connected while it is running to verify 14 psi while it is dying?

 

What is gum cutter? I am able to keep it running with starting fluid. If I
remember correctly, it was staying at 14 psi while it was dying. After it
died, it dropped to 10-12 psi. Is there a way to test the injector without
taking it into a shop? If the pintel isn't opening up, does that mean it's
just gummed up, or could it need replaced?
Wes

 

gum cutter starting fluid the same thing, even if you tested out the
injector with an ohm meter and i have no idea what the specs are,doesnt mean
it is anygood, you would just have to do what we do, if all else tests out,
connections, fuel pressure, all sensor values, timing set to specs, you
would have to take the next step and replace the injector, cause you cant
see what is happening with it internally,

 

The ASD relay controls the ignition, yes, but also the fuel pump and also
the injection. It is the "master shutdown switch".

Ooohboy. Chilton books will get you nowhere in a big hurry. You need a
factory book. They're not hard or expensive to get.

Good way to fry a fuel injector.

Has the throttle body itself or the fuel injector been swapped? Although
physically interchangeable, different-year versions of this same system
run at different pressures. Starting in '91 or '92, the system pressure
was increased to 39psi, and the later injectors aren't compatible with the
early lower-pressure system.

Try this: Remove the battery negative cable from the battery and
leave it disconnected for two minutes, then reconnect it. Get in the car
and crank it, then check the codes and report what you find. I'm beginning
to suspect you'll see an 11.

 

Does removing the battery negative for 2 minuits reset the computer ?