Does bosch LH 2.4 has a dashpot?

[Sam]

Hi guys, still having a stalling issues on my 89 after changing the aic, maf, complete distributor. The symptom is just like what people describe as a failure of the dashpot where the rpms fall too quickly and tend to fall below idle (to around 400rpm) before bouncing back and idling high at around 1300. Typically i'll get a stall after a period of hard acceleration. If I release the pedal and quickly put the car into neutral, the rpms fall too low and the engine cuts out.

Everything i'm reading says that the LH 2.4 has no dashpot and is regulated on the ecu. I have read in a few places that say the 89 ecus are defective and i should try to find a '90 to replace it with. Maybe I have a weird 89 thats supposed to have a dashpot?

[Jordan]

No dashpot. I have another ecu you could try, but that generally isn't how they fail.

[hutch]

Yup like Jordan said no dice on a 2.4 car, but I'm pretty sure you can add them. I thought I had heard of people doing that when they wanted to run a BOV to help somewhat with stalling out between shifts.

It would certainly just mask your symptoms but maybe thats all you need since it sounds like you've tried the big culprits. I assume you have checked your vacuum lines throughout the car? Its amazing how a small leak can affect the running of the engine. Check your intake manifold grommets, PCV system, listen for any hissing behind the dash, check if there are any rotted lines, etc. and maybe you'll come up with something. Maybe your BPV is torn and letting some air out between shifts?

I didn't think 89 had it, but is this an EGR car?

[Crazyswede]

be sure to check all of your vacuum lines, intake boot connections, and even your intake gasket to to be sure there are no air leaks. A can of propane with small tip fitting is useful...turn the propane on lightly and move the tip around various components in the engine when its idling. If your idle goes up you found a leak.

[Jon1]

Sam, I second the recommendation to check the BPV, aka Hooter valve.

[DrewP]

Check around the boot that connects to the turbo inlet too, they get old and crack around the bellow-ey areas and around the bung where the bypass valve goes into, and can be hard to see unless you remove it.

If it's an EGR car make sure the valve on the bottom of the intake manifold is on securely and isn't leaking or stuck open from being clogged up with carbon. An easy way to isolate that as a possibility is to loosen the valve with the two bolts and slide a slice of an aluminum can between the valve and the intake manifold to seal the port and snug it back up. I have driven several cars indefinitely with that "fix" done to them...

[Geoff]

Sam, I second the recommendation to check the BPV, aka Hooter valve.

X2
The symptoms you describe sound like classic hooter valve failure.

[Sam]

Thanks for the suggestions. Guys, will my 9-5 hooter valve fit in there as a replacement? If its bad i'm going to have to hunt around for another one of these (now defunct) stratmosphere valves. I have had mine in the 9-5 for nearly 10 years. Should have bought two!

[DrewP]

Yes, it'll fit, they all use the same valve (size wise at least).

[SwedeSport]

The Viggen / Aero Hooter is supposedly an upgrade to the standard one? I think it holds boost a little longer. Can someone verify that?

[Crazyswede]

The Viggen / Aero Hooter is supposedly an upgrade to the standard one? I think it holds boost a little longer. Can someone verify that?

yes that was the common upgrade a while ago.

[Jordan]

The bosch (115?) valve was NLA'd a while ago, now all they have is the non-brass diaphragm version. However GM (SAAB) and VW use Kaiser as the current genuine manufacturer and have the brass diaphragm

[Sam]

Any info on that PN#, or should i just go get myself a forge? I always stayed away from the forge because of the claimed maintenance requirement. I have enough maintenance with 3 saabs, no need to lube my valves by hand!

That's what she said.

[Jordan]

It looks like the best deal right now is a Genuine SAAB one eeuro # 4441895G. It's made by Kayser, we actually carry the Kayser direct from an importer, but it is more money!

[Geoff]

Did you check to make sure yours is bad first? You can easily check by unplugging the vacuum hose, put a clean one on, then suck through the hose. If you feel resistance and can pull a vacuum then the valve is good. If you can suck through the hose (hehe) and can't pull vacuum then the valve is bad.