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I did ask about this issue earlier and problem is not resolved.
Hot starts a problem when parking the vehicle for a while where the closed hood gets everything under the hood *heat soaked*, including TB, engine mounts, vac lines, connectors, DIC, harnesses etc. Never a problem at idle as part of driving around with a hot engine.
Engine starts fine cold and is fine underway [good power and WOT performance]. Hot starts kick off great, engine stumbles, RPM's surge as TB tries to avoid a stall, can/does stall. When hood opening one can see the engine moving in its mounts as this surging/stalling occurs. By revving the engine for a bit at a hot start, and getting into gear [automatic trany], on throttle throttle plate position allows one to drive away without any problems and again, there are no issues underway. The hot start issue is like something is switching on and off and the TB and TB idle control behavior/surging/stalling may be from a fault in the TB or just the way the TB reacts to something else. This "switching on and off" may simply be the TB reacting to some other fault [control instability].
TB is quite new, looks shiny and clean inside. Two years old, less than 8K
All vac lines seem good, have looked and felt for problems. http://www.saabnet.com/tsn/bb/9-5/index.html?bID=263249
Yesterday: - problem persists after
Pulled DIC and cleaned its contacts, removed its black shroud and the bits underneath looked fine. The DIC is relatively new, not putting many miles on this Saab.
Pulled the plugs. All look the same, light ivory color on the insulators, all 0.39" gaps, reinstalled.
The CPS is new, replaced a while back with the same hot start issues, so problem seems elsewhere. Yesterday I disconnected the CPS connector and reconnected with contact cleaner/lube.
Disconnected TB connector, contact cleaner/lube.
Reinstalled DIC with contact cleaner lube. All of the female connectors are forward, none appeared pushed back. Did note that upper contact nearest driver does not have a female connector.
Cleaned the TB throttle plate for good measure and put a drop of oil on the pivots. Worried that hot start with lower idle air might involve throttle plate binding/sticking and that could be an explanation for the surge/stall issues.
There are no fault codes.
The problem seems quite repeatable with a hot engine, hood parked with hood closed so things are heat soaked. Hot starts always start OK, but idle control is very erratic and it takes effort to avoid a stall. If one can get on throttle its OK. So the problem really seems to be one where the throttle is mostly closed. With a hot engine, idle combustion air flows are very low and the throttle plate will at a mostly closed position that does not occur with cold or not so hot engine bay. But complicating this is the fact that one can be driving around with a hot engine bay with no engine problem idling at a traffic light and this is also true soon after a difficult hot start. But in that case, the heat soaked TB is quickly adapting to cool intake air.
I think that I am talking myself into thinking the problem is the TB, but that is a $$$ experiment to replace. Could be mechanical or the internal potentiometers may have conductivity flaw near closed throttle.
Heat soaked TB, idle control unstable at low throttle air flow.
Any thoughts?
posted by 108.207.118...
, Wed, 31 May 2017 20:18:01, Sat, 17 Jun 2017 13:47:07, Wed, 31 May 2017 21:08:34
, Fri, 2 Jun 2017 03:27:37, Fri, 2 Jun 2017 08:42:11
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