# 89 SE bucking like a broncho



## kpa2 (Feb 10, 2005)

89 SE. This a weird problem. I seems to happen after I park in an incline and shut the engine off. When I start the car and drive, after 1 minute will buck like if its staving for fuel. I put in neutral and rev the engine, and the tach is erratic between idle and 3000 rpm. If at says 1500 rpm, I put my foot on the gas, and the tach will just stay at 1500 rpm for a couple of second and then shoot up to 3000 rpm plus. Over 3000 rpm, it revs fine. It does not matter if the fuel tank is full or close to empty. After driving for about 20 minutes (bucking between 1000 and 3000 rpm when I put my foot on the gas), the problem goes away. The problem comes back when I park in an incline again. (My driveway slopes up 15 degrees or so). It happens both in neutral and drive. I have already changed the fuel filter. I also just had an emission test 2 weeks ago to renew my tag and its passed, but I had to drive around for 20 minutes for it to stop bucking before I took it in for the test. Any suggestions on where to start?


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## Matt93SE (Sep 17, 2003)

Park in the street from now on? 


Hmmm, ya got me on that one.
sounds to me as if you've got a bad vacuum hose somewhere... possibly check your charcoal canister for being full of fuel as well. sounds to me like you either have a loose vacuum hose or bad intake manifold gasket, or you have fuel leaking somewhere in the engine when you park the car on a hill.

also could be a fuel pump issue.. the pump is sealed and submerged in the tank.. it's possible that it could be leaking internally causing issues with the pump, or some other freak occurence like that. you may try sticking a fuel pressure gauge on your line and see what happens to it.


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## old90 (Jan 18, 2005)

I think Matt93SE is right. After the engine runs long enough to get hot it expands and closes a possible gap that sucks in air when the engine is cold.

You may want to run a vacuum test on the engine.

It could be a bad vacuum hose or a bad gasket.

old90


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## kpa2 (Feb 10, 2005)

old90 said:


> I think Matt93SE is right. After the engine runs long enough to get hot it expands and closes a possible gap that sucks in air when the engine is cold.
> 
> You may want to run a vacuum test on the engine.
> 
> ...


I am open to all suggestions. However I have not parked the car on an incline since Saturday and I have had no problems. I would think that if it was a bad vacuum hose or a bad gasket the problem will show up everyday. I will have to wait till it happens again to start snooping around.


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