1991 s-10 blazer won,t idle after it warms up

daddy23444 · 05-10-2009, 06:13 PM

I have a 1991 s-10 blazer w/4.3l v6 throttle body injection.I can get it started and it runs fine for about 5 min.then stalls.I can restart engine runs about 30 sec. then stalls. can anyone help me out here. thanks

pat mcgroin · 05-13-2009, 07:53 AM

I would suggest to try it with a scanner plugged in.
The computer goes from closed loop (predetermined settings) to open loop about that time.
In open loop it is using any readings it gets from the engine to determine how to set it self
It is possible that the throttle posistion sensor or something else isnt giving a correct reading and the scanner may help to determine which one.

Many auto parts stores will let you borrow one for just a deposit.

**octaneman** · 05-13-2009, 03:21 PM

Hello daddy23444

The problem you describe sounds like a bad ground to the injector. First, does the check engine light remain on or off when the engine is running? If the check engine light remains on, the computer has set a hard code which has to be removed after repairs are done. If it's off or goes on intermittently, the computer may try to go into "limp home mode" getting default values set by the manufacturer. You must understand, that even if you rent a scanner to pull out the codes, the scanner will only give VALUES in NUMBERS that only a trained mechanic will understand. It will not pin point you exactly to where the problem is, only its possible location. The car's computer may set multiple codes in a given problem given the fact that the systems are interdependent of one another. When a sensor fails, it does not mean that it is bad, the most common problems are usually corrosion on wires, bad ground connections, faulty ignition wires, blocked fuel and air filters. All this must be taken into consideration before replacing expensive components. My suggestion to you would be visually inspect everything FIRST, clean and tighten up loose ground wires even though they seem OK. Then disconnect the battery and reconnect it after 2 minutes, this will will erase all codes set by the computer. BE ADVISED THAT DISCONNECTING THE BATTERY WILL REMOVE RADIO CODES AND PROGRAMS. Make sure while disconnecting the battery that you use common sense SAFETY FIRST! When your satisfied that everything was done and the problem persists, note down any change in behavior and post back..

hope this helps.

05-10-2009, 06:13 PM	#1 (permalink)
daddy23444 Registered User Join Date: May 2009 Posts: 1 OS: xp	1991 s-10 blazer won,t idle after it warms up I have a 1991 s-10 blazer w/4.3l v6 throttle body injection.I can get it started and it runs fine for about 5 min.then stalls.I can restart engine runs about 30 sec. then stalls. can anyone help me out here. thanks

05-13-2009, 07:53 AM	#2 (permalink)
pat mcgroin Registered User Join Date: May 2009 Location: Toledo Oh. Posts: 484 OS: XP Professional SP2 Vista Ultimate SP2	Re: 1991 s-10 blazer won,t idle after it warms up I would suggest to try it with a scanner plugged in. The computer goes from closed loop (predetermined settings) to open loop about that time. In open loop it is using any readings it gets from the engine to determine how to set it self It is possible that the throttle posistion sensor or something else isnt giving a correct reading and the scanner may help to determine which one. Many auto parts stores will let you borrow one for just a deposit. Last edited by pat mcgroin; 05-13-2009 at 07:54 AM.

05-13-2009, 03:21 PM	#3 (permalink)
octaneman Mentor Join Date: May 2009 Posts: 498 OS: WINXP	Re: 1991 s-10 blazer won,t idle after it warms up Hello daddy23444 The problem you describe sounds like a bad ground to the injector. First, does the check engine light remain on or off when the engine is running? If the check engine light remains on, the computer has set a hard code which has to be removed after repairs are done. If it's off or goes on intermittently, the computer may try to go into "limp home mode" getting default values set by the manufacturer. You must understand, that even if you rent a scanner to pull out the codes, the scanner will only give VALUES in NUMBERS that only a trained mechanic will understand. It will not pin point you exactly to where the problem is, only its possible location. The car's computer may set multiple codes in a given problem given the fact that the systems are interdependent of one another. When a sensor fails, it does not mean that it is bad, the most common problems are usually corrosion on wires, bad ground connections, faulty ignition wires, blocked fuel and air filters. All this must be taken into consideration before replacing expensive components. My suggestion to you would be visually inspect everything FIRST, clean and tighten up loose ground wires even though they seem OK. Then disconnect the battery and reconnect it after 2 minutes, this will will erase all codes set by the computer. BE ADVISED THAT DISCONNECTING THE BATTERY WILL REMOVE RADIO CODES AND PROGRAMS. Make sure while disconnecting the battery that you use common sense SAFETY FIRST! When your satisfied that everything was done and the problem persists, note down any change in behavior and post back.. hope this helps. Last edited by octaneman; 05-13-2009 at 03:32 PM.