Rough idle & hiss - possible fuel regulator?

[aristoquack]

Hi,
I have a 1990 Toyota Camry 4 cylinder with 122,000 miles. I've been trying to fix a rough idle for a while, researching & reading the forums here & other places but haven't gotten it fixed yet. I've got a similar problem to a lot of other owners - the engine wants to stall at idle whether I'm at a stop light or in Park. Highway speed no problem, no hesitation or bucking & fuel economy seems to be about the same.
Here's what I've done so far:
- new plugs & rotor (checked wires & dist cap - ok )
- new coolant temp. sensor
- removed & cleaned throttle body & IAC valve
- removed & cleaned egr & vsv
- cleaned, checked or replaced most if not all vacuum lines in & around the throttle body including the brake booster

The fuel filter is next on the list but I did notice a hiss coming from the rear of the engine on passenger side. I sprayed some carb cleaner while the engine was running & sure enough the rpm's went up when I did that. I think that's where the fuel regulator & fuel rail are. I did change the vacuum line going to what I think is the regulator but no change. So my question is could there be a vacuum leak at the fuel regulator or somewhere in that area? Has anyone had this problem & Is it an easy fix. Thanks.

Stewart

[new echo owner]

You didn't mention anything about the PCV valve and its hose, did you check them? I believe they are on the front of the rear valve cover by the passenger side. There is also a valve switch valve back there too. And don't forget the grommet for the valve, it cracks and leak over time.

N.E.O.

[Doctor J]

On the intake plenum there are several vacuum fittings for optional equipment [cruise, etc] If not used they are capped with plastic caps. Check to make sure that there no open fittings is there.
Second, each injector has sealing grommet at the place it enters the port in the cylinder head. Over the time the grommets can become stone hard and shrink. When the engine is covered by dirt and grime its can form a false seal, however after the cleaning, the "seal" is gone and the outside air is sucked in.
The pre 92 3sfe does not have PCV valve [unless it is used euro engine or one from RAV4];
There is also the air tube with two hoses attached for Power steering idling up, the hoses connected to the pressure valve in the power steering pump, and these hoses can crack and leak, admitting the outside air.

[aristoquack]

Thanks Doc,
Yeah, I didn't think this engine had a pcv valve but I wasn't sure - but I did clean the hose & fitting going from the valve cover to the throttle body. I'll check around power steering pump for problems but if it's the grommets around the injectors, are they difficult to change, do I need to remove the fuel rail & can I buy just the grommets? Thanks.
Stewart

[new echo owner]

Originally Posted by new echo owner

You didn't mention anything about the PCV valve and its hose, did you check them? I believe they are on the front of the rear valve cover by the passenger side. There is also a valve switch valve back there too. And don't forget the grommet for the valve, it cracks and leak over time.

N.E.O.

I guess it helps if I am thinking in terms of a four cylinder instead of a V6.

[Doctor J]

Stewart,
Repeat the "carburetor cleaner" test to rule out intake manifold gasket [it can leak vacuum too].

[jcb62988]

I had a similar problem with my 91 accord, turned out to be a idle control thermo valve on the throttle body, the valve seat had loosened up i tightened it and it now idles perfectly-not sure if this helps

When you said you cleaned and removed the egr and IAC, did you check them for proper operation? I think the haynes manual tells you how to check for proper operation... while cleaning out stuff helps alot, sometimes parts just need to be fixed/replaced

before replacing parts, make sure thats your problem, or you will turn your car into a money pit

[aristoquack]

Hey Doctor J,
Thanks for the tip about the vacuum lines on the power steering pump - one of the lines was not attached & it runs great after putting it back on. That's been driving me nuts for a very, very long time - thanks again.
Stewart

[jroc07gt]

where are these power steering vacuum lines located at? can someone post a pic please? i noticed on my powersteering pump that there was a nipple on the bottom broken off so the hose was disconnected. i thought that causing me to leak powersteering fluid though.

[fredk]

mine fell off to, i just capped the hoses off