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a?c kills my engine!

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Old Jul 26, 2003 | 05:11 PM
  #1  
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csgray
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a?c kills my engine!

i have a 90 bronco and every time i run the air the engine dies
it runs fine when going down the road but just at idle times when i start to give it gas. it seems to me the idle shoud be around 8 or 900 but it idles at 500?i s that too low?
please help!
thanks1
 
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Old Jul 26, 2003 | 06:41 PM
  #2  
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BroncoRoadKill
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From: San Antonio, Texas
a?c kills my engine!

Year and other info about your rig would be helpful.
But, on a carburated model there should be a solenoid bolted to the side of the carb, and when the air cond. kicks in, the solinoid bumps the throttle up a tad to make up for the drag.
Hope this helps.
 
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Old Jul 26, 2003 | 11:58 PM
  #3  
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a?c kills my engine!

its a 1990 efi
so thanks but doesnt help
 
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Old Jul 27, 2003 | 02:39 PM
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TexasBronco
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a?c kills my engine!

If idle speed drops too low to maintain an idle when AC is engaged, the Idle Air Control Valve is probably blocked w/ dirt/oil/debris. Remove and clean throughly, and make sure the IACV is working. It should increase air flow and maintain idle speed when AC turns on. It does for my son's 90 Bronco w/ 5.0L engine.

My idle is usually about 700 rpm when fully warmed.

good luck
 
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Old Jul 27, 2003 | 07:02 PM
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Copper93
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a?c kills my engine!

This must be something inherent with the 90 broncos. My does the same thing. When the A/C is on and I crank the truck it dies after a few seconds. The second time I crank it, it does fine or the idle bounces like a ping pong ball till it settles itself in.
 
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Old Jul 27, 2003 | 07:49 PM
  #6  
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TexasBronco
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From: Katy, TX
a?c kills my engine!

I also found that the engine timing greatly affected idle stability on my 90 Bronco.

For some reason, the standard 10 deg BTDC setting would provide poor idle stability and poor acceleration. I think now, perhaps the harmonic balancer may be damaged corrupting the timing settings marked on the balancer.

Check your timing and experiment w/ different, lower settings. I found that retarding timing about 3-4 degrees made a huge difference; better idle stability and good acceleration.

regards
 
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Old Jul 27, 2003 | 08:38 PM
  #7  
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a?c kills my engine!

how do i adjust timming on a efi?
 
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Old Jul 28, 2003 | 01:01 AM
  #8  
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Seabisquit
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a?c kills my engine!

It could also be that your A/C clutch is starting to go bad. Might want to search for info on how to adjust the timing on a EFI. I did by adjusting the distributor position, and it worked out great for me, but many say don't do it...your call.
 
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Old Jul 28, 2003 | 08:29 AM
  #9  
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fcarruth
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a?c kills my engine!

I bought a timing light for mine but before I did this, I did the following and it worked. I would loosen the distributor bolt and then start the truck up and warm to normal operating temps. Get your wife or a dependable friend in the cab to put it in gear with their foot on the brake and slowly give it gas until they feel they are about to take off. At this point, turn the distributor clockwise until it pings and then back it off counter clockwise just a hair and then turn it off. Tighten the bolt and drive it and make sure you do it up a hill or pulling a trailor so you can verify the timing under a load. I got mine correct the 1st time but was probably lucky. Once I tried the timing light, I had it set at about 12 degrees. I then set it between 10 and 11 degrees and it runs like a top.

Hope this helps.

As far as it stalling the engine, mine did that and it was the compressor clutch had locked up and had to be replaced. Maybe your's is just the timing though.
 
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