Jump to content
Ultimate Subaru Message Board
Sign in to follow this  
1slow_si

starts but wont stay running?

Recommended Posts

I just changed the computer in my 91 loyale and it started right up:banana: but it wont stay running. When it starts the rpm's shoot up to about 2k and then dies. Is this a common problem? Ideas?

Thanks

Share this post


Link to post
Share on other sites

I checked all of the vacuum lines and found nothing? I didn't see one hooked to the air box? Unless you are talking about the pcv system? It will start everytime but just shuts of like it's running out of fuel. I connected the white connectors and hear a clicking but the fuel pump doesn't cycle, So I ran 2 wires from the battery to the pump and same thing? I put a test light on the neg side of the coil and to ground and can see the pulses when the coil fires. So I have spark and fuel, What can it be?

 

 

 

Check the vacuum hose connected to the firewall side of the airfilter box. Disconnected? Loose?

Share this post


Link to post
Share on other sites

Make sure the MAF is plugged in

 

Check that the PCV system is sealed. This will cause the car to stall out. Have to have the Oil cap on and everything.

Share this post


Link to post
Share on other sites

The boys are steering you in the right direction IMO. The Mass Airflow Sensor is the next suspect. See this thread.

 

http://www.ultimatesubaru.org/forum/showthread.php?t=71025&highlight=starts+dies

 

You might start with checking the hose connection at the MAF. Then pull the airbox cover and check your air filter.

 

If no joy, let us know.

Share this post


Link to post
Share on other sites

Another thing to check is the ECU for codes. It sounds to me that the ECU is shutting down the fuel pump. If it is then you should see a code set.

 

You could try spraying a small amount of starter fluid into the intake when it starts to die and see if that helps keep it going. If it tries to keep running then it seems the pump is being shut down.

Share this post


Link to post
Share on other sites

you said you connected the White connectors, and got some clicking? Don't you mean the green ones?

 

When you connect the green ones and turn the key on, the fuel pump will cycle on/off with the clicking under the hood. If the pump doesn't cycle, use your test light to check the voltage at the pump. If you have voltage, then it's probably a bad pump. You said you jumped 12v straight to the pump, and it still didn't work then?

 

-Dave

Share this post


Link to post
Share on other sites

I think you guys might have something with the MAF Sensor. I forgot that I wanted to clean it and couldn't find any MAF cleaner, so I used windex. I figure it should be ok since it's mostly alcohol and not a harsh solvent:confused: . Anyhow, The ecu is just giving me 5 short flashes (I assume this is normal) and the fuel pump gets 12v when I turn the key on (Not sure when running) but I don't hear it cycling with either or both connectors plugged in, I just get the solenoids clicking under the hood. Is this normal? BTW, Thanks to everyone for the help and whoever posted the link to the "FULL" FSM PDF. I found a flowchart that walked me through the steps of diagnosing a no start (weak/sometimes no ignition pulse) problem that led me to replacing the ecu and now it kinda runs and my $300. beater is almost ready for the road.

 

Billy

Share this post


Link to post
Share on other sites
so I used windex. I figure it should be ok since it's mostly alcohol and not a harsh solvent.The ecu is just giving me 5 short flashes (I assume this is normal) and the fuel pump gets 12v when I turn the key on (Not sure when running) but I don't hear it cycling with either or both connectors plugged in, I just get the solenoids clicking under the hood. Is this normal?

Windex is mostly water, not alcohol. Water bad. Get back in there with some electronic connector cleaner spray. 5 short flashes good, that's normal for your engine type. Solenoid clicking normal. Prime suspect remains MAF.

Share this post


Link to post
Share on other sites

The five short flashes is normal and I think it states what kind of tranny is installed if I remember correctly. I also seem to remember something about that code related to the California emissions specs if the car was sold there.

 

Since it appears there are no fault codes that is good. I still recommend you try the starter fluid trick to see if just adding fuel will keep it running.

 

Another thing to look for is the ground to the fuel pump. There may be voltage getting to the pump but there may be no ground to it. Some models switch the ground to the pump through the ECU. Since you are not hearing the pump turn on with the test connectors tied together I think you have a problem there. Here is a test you can try to make sure the pump is getting connection as it should be. Try cranking the engine briefly and then turn the key to OFF. Then turn the key to the ON or RUN position. Do you hear the pump run briefly then? If so, the pump circuit is ok at least but it doesn't explain why the test connection doesn't appear to be working.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×