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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: 1976Scottsdale on October 06, 2008, 07:49:51 AM

Title: 90 or 91 astro van 4.3 700r4 won't idle.
Post by: 1976Scottsdale on October 06, 2008, 07:49:51 AM
I Have Found A 90 Or 91 Chevy Astro Van 4.3 V6 700r4. It Ran Fine Until It A Rebuilt Trans Was Installed And Now It Throws Est Code And Will Not Idle. There Is Supposed To  Be Something Called A Transmission Control Spark Switch. Where Is This Switch Located?
Title: Re: 90 or 91 astro van 4.3 700r4 won't idle.
Post by: VileZambonie on October 06, 2008, 08:22:37 AM
Either you knocked a wire off at the distributor on the ignition module or the module itself is probably bad. Who said there's a transmission spark control switch?  ???
Title: Re: 90 or 91 astro van 4.3 700r4 won't idle.
Post by: 1976Scottsdale on October 06, 2008, 10:11:15 PM
I Work At Oreilly Auto Parts So I Looked Up Sensors For It And It Showed A Two Prong Switch With That Name.
Title: Re: 90 or 91 astro van 4.3 700r4 won't idle.
Post by: 1976Scottsdale on October 07, 2008, 01:34:29 PM
Okay, I have gone out and looked at the viehicle and have some actual first hand info to add.  First off, the previous owner who has it now siad it ran fine before but the trans was slipping, the van is also a 92, not a 91.  He replaced the trans with a rebuilt unit and once he was done he noticed that the engine would run down the road fine but will not idle without feathering the gas the whole time to keep it going.  He then installed a new carquest fuel pump and filter, which made no improvement.  He then replaced the throttle body with an identical unit from another 4.3 engine that was working fine.  When that did not help he replaced the distributor, plugs, wires, cap, and rotor and the computer with new parts.  The thing is great once it gets moving, just will not stay running like it loads up and stalls out when idling.
Title: Re: 90 or 91 astro van 4.3 700r4 won't idle.
Post by: VileZambonie on October 07, 2008, 04:34:55 PM
Scan it for DTC's