Stalling issue

gstacky

gstacky

Member
Hey guys, I did a search and couldn't find any help. I just got my Ty out of storage. Starts right up, sits and runs for a bit and then out of the blue dies. Starts right back up, but if sitting idling will die again. Drive it, runs great down the road, but as it returns to idle coming to a stop it will die. I'm figuring vac lines(look ok, but are original and I have a silicon kit to put on it anyways) or maybe something in the TB, like IAC or something? What's your thoughts, anyone had this and have the fix? I know in a search I read about turning the idle screw up, but that seems to be on trucks that have been apart, this was fine when parked in the fall.

Any help appreciated before I start tearing things apart.
 
Peter

Peter

my Ty and me 25+ years
Re: Stalling issue

I agree, IAC not working right would be the first place to check. I had similar symptoms that turned out to be a vacuum leak. Pressurizing the intake system revealed a few small leaks, such as the TB bushings, but not the main culprit. The lower intake gaskets were leaking badly to the block. I discovered it while fixing a lower intake oil leak.
 
gstacky

gstacky

Member
Re: Stalling issue

Ok, did some playing around and am not getting anywhere. First, I removed the throttle body, cleaned it all up, pulled the IAC and cleaned it as well. Put everything back together, back on the truck, and same thing. Truck starts fine, as the RPM's work their way down towards idle everything is still fine. When the RPM's drop into the 700's it stalls, same thing when you put it into gear. I tried another IAC I had, not sure if it works or not, but got the exact same results. I ran it on datamaster and have IAC values dropping below 10 when this is happening, can someone tell me what that means?

Truck ran fine when parked last year. If I hold slightly onto the accelerator, it seems to run fine, does the throttle screw just need to be turned up for some reason?

Any help is appreciated.
 
Beavis

Beavis

Still plays with trucks
Re: Stalling issue

What about voltage? If the voltage is droping (when the engine settles down), it could be a low battery or weak alterntor not carring the load of the running vehicle when shifted into gear.
 
gstacky

gstacky

Member
Re: Stalling issue

Voltage seems fine, shows 13.7 as it is idling down on datamaster, instantly restarts after, never had to boost it, new battery as of last year. If I sit barely on the throttle it runs fine.

Also forgot I to mention I put a silicone vac kit on too as it had the original lines and that made no difference so it's not vac line either
 
Beavis

Beavis

Still plays with trucks
Re: Stalling issue

What is it on a volt meter when starting? what is it at the back of the alt?
 
atomicmecha

atomicmecha

I hate rust
Re: Stalling issue

Dont wanna start another thread for the same issue ;)

Finally got mine parking lot ready and went to put it in part and poof it died. Turned the head lights on, died. Swapped the battery from my blazer and it helped and stopped it from dying whenever I asked for a lot of electricity. But it still bogs down and will either stall or come close when I put it in park.

Guess I should check the IAC on mine. But anything else I should check?
 
TNPhoon

TNPhoon

1of28
Re: Stalling issue

FWIW - I had a stalling issue when sitting in park/idle at a light. Turned out my coolant temp sensor on the lower intake was bad. After swapped, stalling has ceased.

*Disclaimer though...my truck is a whore and absolutely nothing about it makes any type of sense.
 
atomicmecha

atomicmecha

I hate rust
Re: Stalling issue

TNPhoon said:
FWIW - I had a stalling issue when sitting in park/idle at a light. Turned out my coolant temp sensor on the lower intake was bad. After swapped, stalling has ceased.

*Disclaimer though...my truck is a whore and absolutely nothing about it makes any type of sense.
Click to expand...

Does the gauge in the dash get its value from the same sensor? (i feel like thats a dumb question) cause I've always been curious about why my temp gauge would read just below the middle mark on the dash but yet after driving around for a while the engine bay normally felt just as hot as my blazer normally does, and it has a standard 190 thermostat and runs around 210.

Thinking I might need a new one of those sensors...
 
Sportmachines

Sportmachines

Active member
Re: Stalling issue

Guage on the dash gets its info from the sensor on the block, drivers side. The ECM get the temp info form the sensor on the lower intake. The combination of voltage, or lack there of, the IAC needing to relearn, the coolant temp sensor and perhaps even FP will have an effect on idle and the stumble and die.
 
atomicmecha

atomicmecha

I hate rust
Re: Stalling issue

Sportmachines said:
Guage on the dash gets its info from the sensor on the block, drivers side. The ECM get the temp info form the sensor on the lower intake. The combination of voltage, or lack there of, the IAC needing to relearn, the coolant temp sensor and perhaps even FP will have an effect on idle and the stumble and die.
Click to expand...

Ah. Any way to check them or should I just replace them anyway due to age? I'm thinking just replace them and go from there wouldn't be a bad idea.

Planning on replacing the entire fuel system with the top end rebuild. Guess I'll just add these sensors into the fold.
 
gstacky

gstacky

Member
Re: Stalling issue

Sportmachines said:
Guage on the dash gets its info from the sensor on the block, drivers side. The ECM get the temp info form the sensor on the lower intake. The combination of voltage, or lack there of, the IAC needing to relearn, the coolant temp sensor and perhaps even FP will have an effect on idle and the stumble and die.
Click to expand...

How do you relearn the IAC guys?

Mine doesn't stumble, it's sitting there idling, then just shuts off. Starts back up instantly, runs until the RPM's come back down to idle, then will just shut off again.
 
gstacky

gstacky

Member
Re: Stalling issue

Still not getting anywhere, I've driven it over 30 mph to relearn the IAC as per a gm manual procedure I found in a search, no luck. I've started it up, loaded up the engine by turning on a/c, lights, and wiggling the steering wheel, still will quit coming back to the 750 range in rpm. Runs flawless down the road, just have to two foot it at stops. I guess next will be to try another ECM temp sensor. Any other suggestions?
 
gstacky

gstacky

Member
Re: Stalling issue

Still trying, I have swapped the ECM with another I had, same result. I have switched out the throttle position sensor, same result. I switched out the alternator, same result. Only things I can think of left are the ignition parts or the O2 sensor. This has me stumped. Everything shows great on datamaster. I even ran DM on my other running Ty and all values are very similar. I'm pulling my hair out on this one.
 
gstacky

gstacky

Member
Re: Stalling issue

Problem solved, ended up being the distributor, was corroded badly inside, same issue as another member had. Swapped out with another I had and no more issues. Here is a pic

IMG_20140519_214228_zps0740dbfc.jpg
 
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