idle trouble :((

[blueboy450]

hy everybody, excuse for my english, i'm from Quebec, so that is my problem,, when i'm starting my 944 1983, the rpm goes to about 1200 and drop fast to 200 and the engine wants to stop. So to recover the rpm, i press on the gas and its fix the trouble for a short time. but ,, slowly the rpm goes down and if i turn on the head lights and the fog,, forget it,, my engine die (

help me because its the beginning of the summer here and i want ton run it before the ... winter

[neo the hacker]

I sounds to me like the idle stabilizer valve, (idle control valve), its placed under the inlet manifold and can be removed, u can also clean them out, not sure on the early model, but i think you can. take it off and spray the inside with some carb cleaner, making sure any dirt is removed, if that fails to do the job, replace the unit. And your english is good, better than mine and i'm from there.

[83-944]

83s don't have an idle stabilizer.

First do the obvious, check all your vacuum lines, hoses, wire connections. Any popping, wheezing, backfiring?

[930guy]

early cars do have a idle valve of sorts(not like the new models) and it is very common for the plastic inners to crack with a backfire. If this is the case the valve must be replaced. But start with the basics as suggested by Mr. 83 944

[blueboy450]

thanks guys, but hummm i ear about a idle stabilisator valve but i'm really not sure if i have this in my 1983, some mecanic tell me yes and others say no!! so i will look for a kind of valve who do this job, but i was thinking if it cannot be the regulator of my alternator,,because my idle drop trouble is cause when i put my heads and fogs lights, and sometimes when the fan of my radiator comes on. To answer you Mr83.. i have juste one backfire last summer but my car continbue to run great until this week... So if a have a valve to change,,, where its situate and how its look? thank you and have a nice day

[930guy]

The valve is located under the intake and will have a black electrical plug on the top. It will have 2 hoses on it one in -one out. Unlike the valve in later cars this one is usually open or closed. The computer does not controll its position it either opens it on idle or closes it-off idle.

[blueboy450]

hy, i will look for this valve you describing me,, but i foud too a valve with one in and one out hose ans with two electrical connections. In automobileatlanta book, i can in the diagram,, a valve like the one i describe you, and the name it,, idle stabilisator valve, maybe is this one,,, if you think that is the one ,, i will check this.

have a nice day

[83-944]

okay, did some digging.



Those are the pictures of the two air bypass valves you should have.
#8 is attached to the air filter box next to the brake master cylinder.
#9 is buried under the intake, you'll find it.
Before you go replacing them, pull the hoses off and plug the side going to the intake. Really though, if you're giving it gas to keep it running and it still dies, you probably have a fuel problem. As soon as you open the throttle, there should be more than enough air to keep the engine going.

Try this:
1) Jump the DME relay. The fuel pump usually runs while the engine is cranking via the starter switch, but when in on, the DME uses engine signals to keep the engine running. IIRC You could simply be using up the pressure in the lines, causing it to continue to run.
instructions are here: www.clarks-garage.com
Look up Garage Shop, DME Relay, Tech Info & Testing

2) Check your injectors, this is messy and dangerous (gas), but easily done. You'll need 4 shot glasses and a 10mm socket, extensions, and ratchet. Unbolt the 4 bolts that hold on the fuel rail, wiggle and pull the fuel rail till it comes out. Place the shotglasses under the injectors, stuff rags everywhere, and have someone crank the car while you watch the injectors squirt. Note spray pattern and volume, reassemble everything, report back.

next step, fuel pressure regulator & dampner