87 gl runs when it wants, stalls when it wants

[joebmx]

my carbed 87 gl has been giving me some issues the past few weeks more so since the weather has gotten cold. The car will start up wonderfully and hold an idle so long as i don't kick her down, if I do she then wants to stall out. When driving her, the power is fine, the take off is fine just whenever i let off the gas it dies on me. When it is idling an not stalling it is usually really rough and the tach fluctuates about 200 rpm and will slowly lower itslef until it dies. The idle seems to smooth out when i hold it around 1500rpm. If it dies on me on the road and I drop it in gear to get it running again it will hold its idle jsut fine until i depress the gas again. It will sometimes not stall out if I take it out of gear right where it would want to idle at. So say I take it out of gear when it is at 1000 rpm rather than taking it out of gear at 4000 rpm and letting it drop. just some things i have noticed. I have no clue about carbs and this stuff, so simple clear instruction would be best. Thanks for your help.

[one eye]

Is it spfi? or carbed?

 

If it is SPFI check if it is throughing any codes.

 

After I posted I saw that it is carbed, you might want to check vaccume lines, the cold might have split one, it might even be a vaccume cap that cracked........

 

PS that was my 1000th post !!!!!

 

Jeff

Edited December 28, 2008 by one eye

[Yo'J]

Do you have a stock carb? I'll just guess so for now. I've had this problem before so I'm interested to hear about it. I put a weber carb on and that solved my problem but for you It might be not the solution. Have you done any maintenance like o2 sensor or egr replacement, checked for vacuum leaks? How is your power when its running?

[joebmx]

The power is fine when it runs, that has never been the issue. The problem is that I am getting really good at running 3 pedals with 2 feet all at the same time. As far as I know it is the stock carb. I have not replaced the o2 sensor or the egr valve. both or either would probably cost me more than I paid for the car. I don't really know how to check for vaccuum leaks. I tried the spraying carb cleaner around the lines but had not noticed any change in the idle, i felt like I was missing on some point. Also I can only try that with the engine at its raised idle when it's first started because it will just stall if i try to run it at a lower idle. I did spray some down the carb and the idle picked up a bit but only for a breif moment and after spraying abit more it wanted to stall. I did replace a bunch of lines a while back but the car ran fine afterwards. If i try to pinpoint when the problem really started I think I started running into problems after a seafoam treatment. hmmm....

 

ps congrats on the 1000th post

[Yo'J]

The carb, I think, would be a feedback carb so it gathers info on how the car is acting. The egr can be cleaned if it has no leaks and I have seen the manifold holes completely blocked with carbon fyi. The o2 sensor should be checked and I think, someone should pipe in here, The sensor can be a non subaru item as long as it has the same wire count. If its toast, it will always run poorly like its cold, not necessarily hurting power just economy and emmissions . They can be expensive$100 oem, but if I remember its a 2 wire and a bosch isn't that badly priced$40. Most vacuum leaks would give you a high idle. A clog, well....not so much.

 

http://www.ultimatesubaru.org/forum/showthread.php?t=86141&highlight=stock+carb

 

This might help a little

Edited December 28, 2008 by Yo'J

[zyewdall]

Sounds kind of like the one on my '85 GL.... the shop I took it to (which knew old subaru's pretty well, the owner drove a '86 wagon) told me that there were internal vacuum leaks in the carbureator which were causing it to suction the idle circuit dry, but the power circuit was still working. He recommended rebuilding the carb, to the tune of $300. I ended up having head gasket issues and selling it first though.

 

Z

[joebmx]

I just came back from a 200 mile round trip on the button, 90% highway driving. I filled up b4 i split and when i got home, did the math and got 29.4 mpg. So i do not think my economy is suffering in fact I was very surprised by this the engine has 205k on it. Does that rule out the o2 sensor or should it be legitimately checked?

 

I also played with the idle adjustment b4 i took off, tightening it a little and it idled fine without stalling until i hit a rest stop 60 miles in. It both stalled and then proceeded to idle high and wouldn't kick down. So i then played with the idle adjustment again and had good results, with only a few stalls over the next 140 miles of driving, off the highway off course, and the idle sat steadily around 1200rpm. would timing affect any of this? I also found a vacuum line only connected at one end and could not find its mate, I will post a pic of it tomorrow. it came out of a small black disc that was mounted in the middle and the hose came out of the left face, the I.D. can't be much more than 1/16" its tiny, it also resides right above egr valve.

 

I wanted to check the egr valve but the hayes manual gives directions that seem ridiculous. With the car running it says to check and see that the valve is operating. How can i do that, should it be really obvious if the valve opens and shuts even with no visibility of it? Or should it come out?

 

Thanks again

[The Dude Abides]

Sounds like subymechs car sitting in the middle of university ave:rolleyes: