Author Topic: stalling at stops and idle  (Read 3473 times)

Offline 12gaige

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stalling at stops and idle
« on: October 23, 2015, 08:22:00 PM »
I have begun to rip my hair out.  Have an 87 r1500 2wd 305 tbi. My problem is the truck will stall when coming to a stop, slow turns, and sometimes at idle. I have replaced the tps, iac, egr, and even swapped complete tbi units from other trucks that run perfectly. No matter what i do it will keep stalling, unless i manually bend the throttle shaft to make it idle high (sounds somewhere between 1600 to 2000 rpm). Or if i two foot drive it and make it idle high. No codes, any help would be appreciated. I am about tempted to rip the top end off and carb it.

Offline Irish_Alley

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Re: stalling at stops and idle
« Reply #1 on: October 23, 2015, 09:16:27 PM »
Take it no CEL?
A vacuum leak can cause these problems
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Offline 12gaige

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Re: stalling at stops and idle
« Reply #2 on: October 24, 2015, 02:36:09 PM »
No cel and no leaks that i can find. Changed the tbi to intake gasket. Egr gasket. Ive sprayed with carb spray and water multiple times and can not find any kind of a leak

Offline Irish_Alley

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Re: stalling at stops and idle
« Reply #3 on: October 24, 2015, 03:54:28 PM »
Does your CEL light up when you turn the key to the on position with the engine is off?
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When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline 12gaige

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Re: stalling at stops and idle
« Reply #4 on: October 24, 2015, 04:04:57 PM »
The light does work during bulb check.

Offline Irish_Alley

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Offline Dr_Snooz

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Re: stalling at stops and idle
« Reply #6 on: October 25, 2015, 09:24:57 PM »
^^ THAT is a handy link!
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Offline 12gaige

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Re: stalling at stops and idle
« Reply #7 on: October 26, 2015, 07:23:06 AM »
Yes it is. I may have it pin pointed it down to the distributor. ALL of the sensors are within spec, i will be pulling one out of my perfectly running plow trucks for testing, and if it helps i am going to pick a brand new one up at the dealership.

Offline Irish_Alley

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Re: stalling at stops and idle
« Reply #8 on: October 26, 2015, 09:46:26 AM »
The distributor on these things do do a lot. They give the signal for fuel signal and of course spark.  It will be something new if it causes it to stall to me. Keep us updated 
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Offline 12gaige

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Re: stalling at stops and idle
« Reply #9 on: October 26, 2015, 11:45:26 AM »
Finally got a code. I believe it was 34 (forgot to write it down) MAP voltage low. I tried to reference the post you replied with. But map is teading 30kpa at idle and around 1.0 volt (8.5 to 1.2 volts.)

Offline 12gaige

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Re: stalling at stops and idle
« Reply #10 on: October 26, 2015, 06:28:03 PM »
During open loop the o2 cross counts fine, but once in open loop the o2 only reads rich.

Offline Irish_Alley

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Re: stalling at stops and idle
« Reply #11 on: October 26, 2015, 06:32:58 PM »
So does it have a problem when its cold or just after it warms up?
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Offline 12gaige

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Re: stalling at stops and idle
« Reply #12 on: October 26, 2015, 07:17:47 PM »
It doesn't usually stall when its cold. It has before but, the first minute or two after start up is usually safe to not stall.

Offline Irish_Alley

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Re: stalling at stops and idle
« Reply #13 on: October 26, 2015, 07:32:47 PM »
What. I took that as it normally doesn't stall when cold but after the first couple minutes its safe note not stall. When does it stall? Lol
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Offline frotosride

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Re: stalling at stops and idle
« Reply #14 on: October 26, 2015, 08:30:18 PM »
I chased this problem for years and came to find that i had to raise the idel because everything had worn over the years. Let me guess a guaranteed stall is in reverse with the wheel turned?

 Give me a few to find the article but it is in the tech pages if you find it before me.
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