rough idle at startup
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Joined: Jun 2010
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rough idle at startup
Hi all! I bought an 89 B2 back in Feb. It had a bit of a rough idle but hadn't been tuned up so I bought it and immediatly had it serviced and changed the spark plugs and wires. Now when I start it, the engine sputters and misses for about 30 seconds to 1 mins. Once it gets going and driving at highway speeds it seems to run fine. My line of thinking is that i'm getting air into the fuel system and when i first start it up it takes a few moments to purge the excess air out of the system. It also at times smells like it has a gas leak and I have discovered some gas leaking from a vaccum line around the top of the valve covers. Any help at all would be appreciated. Thanks!
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New User
Joined: Jun 2010
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I replaced the IAC valve altogether and that solved the startup problem momentarily. Then went back to old habits. Still takes forever to crank over and hit and when it does it misses for about a min. After about a min the idle clears up some and i can drive it. There is gas leaking out of a valve to the right rear of the drivers side manifold. It's pushing gas into a vaccum line that goes into the plenim on top of the engine... I have no idea waht this valve/sensor is or does but i'm thinking it may be the source of my trouble.
More Turbo
Joined: Mar 2006
Posts: 687
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If your fuel line is going through this valve, it probably is the fuel pressure regulator. If your oil has a gassy smell to it, That confirms it. When they go completely, the engine runs horrible. It's not that hard to replace, you'll need a tool to get the fuel lines disconnected. I would suggest a Haynes manual also.
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Replaced the PSI Reg and it starts like a champ now... still runs kinda rough... timing maybe off or something. I'll have to have it checked.
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Fleet Mechanic
Joined: Nov 2007
Posts: 1,774
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From: Northeast Nebraska
my dad is having the same exact problem w/ his 88 B2 right now...would the FPR foul out plugs too?
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Postmaster
Joined: Dec 2001
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From: UT
Depends on how the plugs are fouling, but there are a couple of different ways the FPR can fail that makes the engine run rich which fouls plugs. Pull the vacuum line to the FPR and see if there's gas in it. Gas in the vacuum line = bad FPR. If that looks ok, put a fuel pressure gauge on it. Pressure should be around 40 psi. If it's significantly higher than that, the FPR may have failed closed.
