High Idle / Idle speed motor

[NckT]

You could always solder them shut.

[David T]

You could always solder them shut.

That would be OK on an automatic but you really do need them for the 5-speed.

[Bitsyncmaster]

Thanks for the help. Hopefully someone can confirm the order of o ring and plastic ring on the w pipe as i have to put it back together. Guess I'm stuck with a high idle until a good one turns up somewhere.
Do you think this type of leak would affect my exhaust emissions ? I failed CA smog recently and was looking for air leaks that might contribute to the high NOx measurements I got

I don't think the springs would affect emissions unless the higher idle speed affected emissions.

By the way I tried to run with the bad set of springs removed and bolted the holes closed. Car would run OK but when you took you foot off the gas not in gear the engine RPM would really drop to low (about 500 RPM). I tried some software changes in my idle ECU which helped but it still would happen sometimes. So I went back to a used throttle assembly with good springs.

[nickcollins]

[QUOTE=Bitsyncmaster;223430]I don't think the springs would affect emissions unless the higher idle speed affected emissions.



More air means a higher NOx reading, or so i'm told

[Bitsyncmaster]

[QUOTE=nickcollins;223434]

I don't think the springs would affect emissions unless the higher idle speed affected emissions.



More air means a higher NOx reading, or so i'm told

I would think if the lambda is running the mixture is correct at 14.7 AFR. The more air just results in higher RPM. The lambda works at all RPM except when wide open throttle.

[nickcollins]

[QUOTE=Bitsyncmaster;223435]

I would think if the lambda is running the mixture is correct at 14.7 AFR. The more air just results in higher RPM. The lambda works at all RPM except when wide open throttle.

Sounds right to me, more air so the system adds more fuel to keep the ratio hence a higher rpm
I was told that my failed NOx was possibly due to a vacuum leak which also gave me a high rpm so I've been hunting for a leak for a while now.

[David T]

The decel springs (and valves) were meant to reduce emissions during deceleration. It would allow the mixture to lean out so you would get less hydrocarbons. It also makes the ride a bit softer. Not really necessary on an automatic, the torque converter can handle it. Odd thing about the Delorean. The motor is set up exactly the same for the auto and the 5-speed. Usually you see the idle, timing, and advance set up a little differently on a 5-speed vs an automatic, but not on a Delorean! I guess they didn't make as many autos so they didn't have to do emissions testing on them so they didn't tweak them.

[NckT]

That would be OK on an automatic but you really do need them for the 5-speed.

I disagree. I understand what the purpose is for these air admittance valves, but you can remove them in their entirety by replacing the throttle discs or solder them shut. They only open when the throttle is shut and the car is on the over run.

I've set up a few Deloreans with oem no dec valve throttle discs and it has had no adverse effect on the engine running on deceleration at all. I've done this on many other non k jet cars also.