2200rpm idle & stumbles around 3200 when driving, making progress, idle down to 1100, still stumbles above 3k |
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2200rpm idle & stumbles around 3200 when driving, making progress, idle down to 1100, still stumbles above 3k |
RazorbackFan78 |
Sep 8 2015, 06:30 PM
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#21
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3 different layers of paint helps protect if from rust Group: Members Posts: 136 Joined: 29-March 13 From: Bentonville, AR Member No.: 15,709 Region Association: South East States |
Hey guys - I'm trying to track down the cause of my high idle.
I've checked the TPS and I get 20 clicks pre-ignition I've pulled the AAR, soaked it in PBlaster, froze it, put 12v through it, confirming it opens and closes correctly. It also tested around 17ohms I cleaned grounds at headlights, battery neg, driverside engine bay, and visually confirmed trans strap is brand spankin' new (thanks Curt) Now i'm checking hoses for vac leaks and only one seems to drop the idle (drops it to a steady 1100rpm). It's the hose from the airbox elbow that Y's into the AAR and dizzy. See picture. Is this sounding like my dizzy could use a good cleaning? I have other items on my troubleshooting list like MPS, fuel filter and decel valve but wanted to check in with you guys after discovering the vac issue. Thanks for your input. I'm still fairly new to this type of engine....so I'm learning as I go (IMG:style_emoticons/default/biggrin.gif) BACKSTORY: for those of you who like a novel....car had points and idle would bounce between 100-900rpm more often than not. Anytime I'd reach 3200rpm while driving it would studder and loose power, in all gears, and it would also occasionally do it under a heavy foot at lower rpms. I replaced points with Pertronix 1847V and now the cold idle sits on 1100 like a rock for the first minute or so, then over the next minute it climbs to 2200 and holds steady. It still studders around 3200 when driving and occasionally does it at lower rpms when I'm really on the pedal. Attached image(s) |
RazorbackFan78 |
Sep 11 2015, 07:54 AM
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#22
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3 different layers of paint helps protect if from rust Group: Members Posts: 136 Joined: 29-March 13 From: Bentonville, AR Member No.: 15,709 Region Association: South East States |
Thanks for bearing with me guys. I think we're getting close. Here's an update.
I disconnected all hoses, inspected, reconnected. It's now sitting around 1200 +/-100 but it no longer climbs up to 2200 anymore when warmed up. So that may be a small victory. But idle spec is 900 right? So I took the airbox off and immediately started hearing a distinct hissing sound which I don't hear when the airbox is on. The hiss seems to be coming from the left side of the plenum/throttle body area. Also, I noticed a couple of flame puffs in that same area when I was using propane to try and detect leaks. Yes, the propane ignited briefly. Only a tiny puff or two, but I decided to put the propane away and focus on that area. 2 Questions: 1. When I cover the airbox's intake with my hand, the car continues running with barely a noticable drop in idle. But when I remove the airbox and cover the intake the car dies immediately. Is the goal to have an air-tight airbox? It looks like the only two hoses connecting to it are for filtering air, not maintaining a vacuum. Just making sure I'm ruling out the right things. 2. Is the hiss and propane ignition near the throttle body/plenum possibly a good indicator of a vac leak? Maybe a TB gasket or the plenum itself? I wasn't expecting my propane to ignite. Kinda spooked me. Thanks guys! |
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