Qjet dies from a high idle
#1
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Qjet dies from a high idle
Hello from over here!
I've installed a reman qjet from Autoline on my '85 L69, along with new dizzy cap, rotor, coil, leads and plugs. The EGR's been removed, the AIR won't work with the headers and the THERMAC and EFE are missing. I have reconnected the vapour canister and made up the EVAP purge plumbing with new hoses and shiny new clips.
I fired up the car at the weekend and it immediately shot up to a high idle - about 3000rpm (although I think the rev-counter over-reads). I observed as the choke opened, which it did (/hat-tip to sofakingdom!), however as the choke opened, the revs didn't drop or maybe only a couple of hundred rpm. I gave the throttle a blip as the choke was opening and the engine revved up and down, returning to the high idle. Once the choke had opened fully, I gave the throttle another blip and, over about a second or two, the engine stumbled and slowed unevenly until it stalled...
I'll admit I haven't got into the choke tuning, A/F tuning or setting the dwell yet, but I suspect something more fundamental might be happening. Is the reinstalled vapour canister over-fuelling things? I used a new black/greentop vacuum switch. Would this behaviour be caused by a vacuum leak?
Bit puzzled... any words of wisdom?
Many thanks!
Neil
I've installed a reman qjet from Autoline on my '85 L69, along with new dizzy cap, rotor, coil, leads and plugs. The EGR's been removed, the AIR won't work with the headers and the THERMAC and EFE are missing. I have reconnected the vapour canister and made up the EVAP purge plumbing with new hoses and shiny new clips.
I fired up the car at the weekend and it immediately shot up to a high idle - about 3000rpm (although I think the rev-counter over-reads). I observed as the choke opened, which it did (/hat-tip to sofakingdom!), however as the choke opened, the revs didn't drop or maybe only a couple of hundred rpm. I gave the throttle a blip as the choke was opening and the engine revved up and down, returning to the high idle. Once the choke had opened fully, I gave the throttle another blip and, over about a second or two, the engine stumbled and slowed unevenly until it stalled...
I'll admit I haven't got into the choke tuning, A/F tuning or setting the dwell yet, but I suspect something more fundamental might be happening. Is the reinstalled vapour canister over-fuelling things? I used a new black/greentop vacuum switch. Would this behaviour be caused by a vacuum leak?
Bit puzzled... any words of wisdom?
Many thanks!
Neil
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Make sure you don't have any vacuum leaks, then tune it. Start by setting the timing, and go from there.
#3
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Re: Qjet dies from a high idle
I won't be able to get back to the car until the weekend, but the first thing I'll do is get out the brake cleaner and fire it up to look for leaks!
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eightsixseven
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08-14-2015 03:09 PM