Jump to content

94 Sierra Ext Cab Stall at cold start

Razormann

By Razormann
in Ask A GM Technician

Recommended Posts

Razormann Enthusiast

Razormann

Posted
Posted

I have a 1994 Sierra with an extended cab 4x4, 350 engine, auto trans, 173K miles everytime I try to start it when the engine is cold it will fire right up and then die. It usually takes a little while to get it started again. Before it dies is does not stammer or surge or sputter or anything, it just shuts off. It has happened to me a few times while driving both at low sppeds and at high speeds. However for the most part once you get it started it runs very well and there are no problems. Here is a list of everything that has been replaced:

Plugs and Wires

Ignition Module

Ignition Coil

Fuel Pump Relay

Coolant Temperature Sensor

All of these items were changed in the last week, Also the fuel pump is less than a year old.

I had it in the shop and they could not find anything, they said my fuel pressure was good. I am kinda stumped on this one, I am testing the MAP sensor today, I was told that if I unplug it and start the truck it will run crappy but if it stays running that is my problem. I have also heard that it could be the Crank Sensor. Is there a test that can be done it it without a meter? Such as unplugging it or anything?

Any help you can offer would be a great help!!!

bobcat5544 Enthusiast

bobcat5544

Posted
Posted

mass air flow sensor won't shut the engine off like you are describing, only part of your system that can shut off then engine like your turned your key off is the ignition system.

 

Things To Check

ignition switch- see if it loses power coming out if it

pcm-check to see if loses power going into it and also check ground

ignition coil- check to see if it loses power to it

distributor- see if it loses power to it

oil pressure sender - look at it see if oil is coming out of it unplug it

 

all of this (exept oil pressire sender) can be checked with a test light any power loss with stop veh from running

ChevyTech007 Enthusiast

ChevyTech007

Posted
Posted

You need to determine if it is a fuel or fire problem. When it dies and won't restart, take the air cleaner off and see if you can see gas spraying from the injectors. That will narrow it down a lot. Also you need to scan for codes.

Razormann Enthusiast

Razormann

Posted
  • Author
Posted
You need to determine if it is a fuel or fire problem. When it dies and won't restart, take the air cleaner off and see if you can see gas spraying from the injectors. That will narrow it down a lot. Also you need to scan for codes.

 

 

 

 

I have fuel coming from the injectors right up to the point when it dies. As far as codes go that will take some doing I have to locate a code reader and do it at a cold start because when I had it in the shop they said they found no codes...

 

Thanks for the help so far!

Razormann Enthusiast

Razormann

Posted
  • Author
Posted
After it dies, how long do you have to crank it to get it started again?

 

 

 

 

If i return the key to the off position it will start on the next crank and then die. It takes anywhere from 2-10 minutes of that before the truck will stay running.

Razormann Enthusiast

Razormann

Posted
  • Author
Posted
come to think of it do you have any alarm system factory/aftermarket on this truck

 

 

 

 

I do not have an alarm but i do have a remote start system. i removed of the the relays that control the remote start in the thought that if it was trying to send conflicting info to the truck it could no longer do so. I am starting to think that it is the Ignition switch, it sounds like a likely culprit based off of what is happening and what I have been hearing. But I would like to be sure before I dig into that project, it seems a little involved.

:banghead:

Razormann Enthusiast

Razormann

Posted
  • Author
Posted
come to think of it do you have any alarm system factory/aftermarket on this truck

 

 

 

 

I do not have an alarm but i do have a remote start system. i removed of the the relays that control the remote start in the thought that if it was trying to send conflicting info to the truck it could no longer do so. I am starting to think that it is the Ignition switch, it sounds like a likely culprit based off of what is happening and what I have been hearing. But I would like to be sure before I dig into that project, it seems a little involved.

:banghead:

 

 

 

 

 

Nope.... not the ignition switch back to te drawing board....

bobcat5544 Enthusiast

bobcat5544

Posted
Posted
Next I would tap test the ECM, also I would monitor fuel pressure when the problem occurs.

 

 

 

 

there is no way fuel pressure, will cuase this veh to just stop running, if you read what he has stated, it just stops, it does not chuggle, spudder, run ruff. it just stops running like when you turn your key off. If it is fuel related it would spudder then quit...

 

the most likly possiblities is ignition switch, pcm/ecu, ignition coil primary or secoundary, distributor, or power/ground wires.

  • 2 weeks later...
Razormann Enthusiast

Razormann

Posted
  • Author
Posted

After some more poking and prodding and testing, the electrical systems was ruled out. I had someone I trust bring over a real diagnostic machine and nothing was found out of whack in the electrial/ignition system. So we decided that it must be a fuel problem as unlikely as it seemed, since it didn't spudder and die or choke out or anything.

Long story short, it was the fuel filter. I changed and the truck has been running great ever since (Knock on wood)

 

It seemed that my fuel pressure was good once it was running but I was having problems with volume so it would get enough to start but not stay running.

 

Thanks to everyone who offered me advice on this subject you all were a great help and i learned some good troubleshooting skills. Hopefully I won't have to use them again anytime soon....

ChevyTech007 Enthusiast

ChevyTech007

Posted
Posted

 

 

there is no way fuel pressure, will cuase this veh to just stop running, if you read what he has stated, it just stops, it does not chuggle, spudder, run ruff. it just stops running like when you turn your key off. If it is fuel related it would spudder then quit...
:cheers::D

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Latest Articles

  • Posts

    • carkhz316
      2006 Silverado HVAC sensor location in dashboard

      By carkhz316 · Posted

      Oh yes, someone is going to be certainly hitting up GM service/ support for a 20 year old truck.
    • Deadwood
      primary drive belt tensioner

      By Deadwood · Posted

      I bought belts and pulleys for my '20 L5P at Rock Auto a couple years ago. I have used them for many years, and almost always save significant money, especially when I buy maintenance stuff ahead of time.   They carry many OEM parts, which is all I use unless an aftermarket is shown to be same/superior, or if it is an insignificant part or unavailable OEM part anywhere else. RA is usually lower priced, often by a bunch, but parts are sometimes unavailable or out of stock, and I do shop around and sometimes find better prices at other sites.   Be aware that you pay shipping, and if you buy multiple items and they are coming from different warehouses, the shipping can kill the advantage. Planning ahead is best if possible.   If you have a transmission service in the near future, check out their OEM (AC Delco ULV) fluid, usually MUCH less than anywhere else.
    • Deadwood
      10L1000 anyone with High Mileage ? I hate Damocles....

      By Deadwood · Posted

      New member here, very long time occasional guest. Saw this thread, thought it would be a good time to contribute someting. It is only my experience and not a claim that everyone will have the same.   I bought my '20 3500 L5P new and have put 99.9% (literally) of it's current ~400k miles on it myself, with over 50% of that towing loads between 4k to 15k, and to me this truck has been nothing short of amazing. For the first 235k I had zero issues, and from there until 321k I replaced a NOx sensor, two failing glow plugs, and three of the notorious injector connectors. I believe this truck is in part, a testament to good luck, but also good care and following a decent maintenance schedule (I also keep meticulous records.) As a result, it looks as good as a well cared for 70k rig, up and down, inside and out.   At some point before that 321k mile mark I began to get a little spooked about the 10L1000, especially the valve body. Word of mouth about potential issues prompted me to jump on the net to sift through all the noise and determine what all the fuss was about. I routinely take long trips, coast-to-coast and points in between, so roadside breakdowns can be '...a thousand miles from nowhere' and a bit of a challenge, and though I had no issues, my guard was up and activated.   And then I stumbled across a chance to salvage some parts off a new 2025 that had been wrecked in transport. I grabbed a few wear items (alternator, pulleys, etc.) and on a whim asked what the ten speeder would cost me. It was cheap...really cheap. I knew some changes had been made in the '24+ version 10L and were supposedly not compatible, but I called service/parts at my local Chevy dealer and asked why and they didn't know. A call to a well known aftermarket transmission outfit revealed it was very likely it would be fine, but to them not 100% sure.   Because it was cheap (really cheap) and I was spooked, I took the chance. Had it installed by a local shop and it worked like a champ, shifted just like the original. At it's first service at 37k, I had the shop put in a Next Gen valve body kit, which after some initial hiccups and rough shifts, smoothed out though with somewhat firmer shifting.   All that said, I have a very serious concern about my newer transmission as just two weeks ago it suddenly began to exhibit a strong reluctance to engage forward or reverse. It was a bit past due anyway so I took it in for service. The reason it was sticking was due to 'glitter' in the fluid clogging the filter...not good folks, often indicates a converter giving out. We ended up going ahead with the new filter and fluid, first to see if it would move and shift, and then if so buy me a little time. It did, and I've driven it over a thousand miles and it is shifting smooth, no noises or slipping. Regardless, it looks like a third gearbox is in my future so I can resume taking long trips with some confidence. In the very short term, my curiosity will have me examining the fluid to check how much glitter has reappeared.   An earlier poster had alleged, in the context of 10L100 failures, that it is another example of how we seasoned citizens somehow descend into hysteria, lose control of our senses, and react irrationally after brief encounters with the idiocy of the internet infosphere. Let me say (and I have used and abused said internet since it's infancy) there is no segment of the populace that has a corner on over-reaction to digital garbage. Just as my offering of experience in this arena is purely anecdotal and should not be considered gospel or all-encompassing, I believe it is still worthwhile information to consider, along with other relevant anecdotal experiences about things like complex transmissions, especially when balanced with other sources.   So to answer the original question, yes I got high miles out of my first 10L, trouble free for 321,000. Now I really wonder how much longer it would have went. Did I 'overreact' to the internet ghouls by replacing a 'good' one with a 'bad' one? Maybe. Who knows, the thing might have taken a puke a 100 miles later. So I'll just fix it again, then move on and start thinking about all the other stuff that will eventually wear out. It still has the original brakes (they're at ~60%), original injectors/pump, turbo, water pump, etc....pretty much original everything. Knock on wood.
    • swathdiver
      6 Speed vs 8 Speed

      By swathdiver · Posted

      At peak temperature.  They get to cool down and warm up more, especially those with the external cooler.  I have three GMT900s and one of them has over 225K on its original transmission.  Fluid gets changed about every 36K miles, all of it.     It's not the bean counters, it was the government.  They had to meet CAFE standards and other government requirements.   To get around that, we tune them and modify them to our liking.
    • GMCustomerService
      Will not stay in Reverse

      By GMCustomerService · Posted

      Our customers' safety isn't something we take lightly. To ensure you get the proper assistance for your truck's repairs, please fill out the form at https://s.chevy.com/support-request with all pertinent details including your username.

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...