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88 K5 Issues

C. White

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I have a 1988 K5 Blazer that keeps dying out when coming to a stop. Other than that it runs great, even at idle. Also it doesn't die at every stop just sporadically. I've changed idle control, Pvc valve, plugs and wires, and still no change.
 
I have a 1988 K5 Blazer that keeps dying out when coming to a stop. Other than that it runs great, even at idle. Also it doesn't die at every stop just sporadically. I've changed idle control, Pvc valve, plugs and wires, and still no change.

First, welcome. :)

Second, stop throwing parts at it. Gets expensive fast and new parts are more likely to be pieces of junk compared to what you are removing.

Does the check engine light work properly? Do you have any codes, or ever see it come on when driving? Does it idle at the appropriate RPM? Does your cruise control work?

Lastly, just to pull or check for codes, don't buy any tools. It is as simple as using a paperclip on these systems.
 
^^^^^this. Plus there are so many free tools out there to help you log data. Such as Tunerpro rt or Winadl. I wasted a bunch of money replacing sensor on my tbi rig, until i started using tuner pro. I found the issue within 3 minutes of having it plugged in.
 
^^^^^this. Plus there are so many free tools out there to help you log data. Such as Tunerpro rt or Winadl. I wasted a bunch of money replacing sensor on my tbi rig, until i started using tuner pro. I found the issue within 3 minutes
 
Thanks for the info. My cruise doesn't work could that be an issue? Also no check engine light but I will pull the codes to see if it has any. Fuel pump or regulator maybe?
 
My first guess would be a vacuum leak,a hose probably cracked or came off--possibly the one that operates the cruise control vacuum diaphram ,or maybe the PCV valve hose,brake booster..EFI base gasket is another possibility..if you can keep it from stalling by giving it some gas with the brakes applied,its most likely a vacuum leak..
 
What's the best way to check for vacuum leaks. I don't here one and I've tried spraying starter fluid around to find it with no luck.
 
Could be fuel related have you replaced the fuel filter? If not that's cheap and easy. I would suggest data logging at this point.
 
My first guess would be a vacuum leak,a hose probably cracked or came off--possibly the one that operates the cruise control vacuum diaphram ,or maybe the PCV valve hose,brake booster..EFI base gasket is another possibility..if you can keep it from stalling by giving it some gas with the brakes applied,its most likely a vacuum leak..[/QUOTE
OK found a cracked T fitting coming from throttle going to PCV valve. I replaced it and all three hoses. Runs way smoother but still dies out. Drove it about 30 miles and it died 3 times while coming to stops. Going to check for more cracked hoses in the A.M. It seems worse when motor is hot.....?
 
Someone told me the torque converter could cause this problem. Any thoughts and if so how? Thanks again guys for all your help.
 
I spray carb cleaner at suspect hoses to pinpoint vacuum leaks..the rpms will change,it'll either speed up,or want to stall out (different brands of carb cleaner act differently)--some use an unlit propane torch ,but I almost went "whoof" using that method once when a bad spark plug wire ignited a build up of the propane..it scorched my beard!..:doah:

If the lock up torque converter decided not to unlock,it would stall at every stop,like a manual transmission and you didn't push in the clutch would--..
 
I have a 1988 K5 Blazer that keeps dying out when coming to a stop. Other than that it runs great, even at idle. Also it doesn't die at every stop just sporadically. I've changed idle control, Pvc valve, plugs and wires, and still no change.

If you have suspicion of the fuel pump/filter, and if you have autozones where you live, you can borrow their fuel pressure checking setup to confirm. I've gone so far as to test pressure both before and after the filter to check restriction. It's a bit of a pain with TBI, but it is far better than guessing.

These rigs are prone to low fuel pressure from the in-tank fuel hose splitting from ethanol (if the pump/hose is pre-ethanol) and as the split gets worse it causes all sorts of issues. I never had any issues with stalling coming to a stop, but who knows. If it's free to test, it's free.

Since it starts right back up you are going to have a bit harder of a time to diagnose. Strictly coming to a stop, I'd check fuel pressure, vacuum, and why your cruise doesn't work.

Autozone may loan a vacuum tester as well, if you've got a vacuum leak you'll see it with the vacuum gauge. Without really thinking about the cruise vacuum setup, I can't think of a way that it could make a vacuum leak when you depress the brakes, but there is a vacuum break that is controlled via the brake pedal.

Tunerpro would help by allowing you to see if your ECM is receiving vehicle speed towards resolving the cruise issue. From my experience your version of VSS is pretty robust and unlikely to fail, but it does rely on the mechanical workings of the speedometer.
 
I've had a few power brake boosters fail,the diaphram inside rots and when you apply the brakes,the vacuum leakage wants to stall the engine..but he'd probably notice lack of power assist as well..
 
I've had a few power brake boosters fail,the diaphram inside rots and when you apply the brakes,the vacuum leakage wants to stall the engine..but he'd probably notice lack of power assist as well..
It has a new booster and master cylinder.
 
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