1987 k-5 blazer cranks and starts but won't stay running
Throttle body sprays out gas when key is turned, it will start but only for few seconds, rapidly pumping fuel pedal keeps running but very rough and dies right away after stopping pumping, 350 engine in it.
An expert who has achieved level 2 by getting 100 points
An expert that got 5 achievements.
An expert whose answer got voted for 20 times.
An expert who has written 20 answers of more than 400 characters.
Re: 1987 k-5 blazer cranks and starts but won't stay...
Sounds like a large vacuum leak,low fuel pressure,fuel pressure regulator failure, idle air control valve stuck open,plugged fuel filter.Also check for good consistent blue spark at spark plugs or jumped timing chain.Hope this helps!
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
Maybe a problem in the fuel pump circuit. Check fuel pressure with engine off, and key turned to on, not start. If no pressure, diagnose the pump circuit at the fuel pump relay. One terminal for the relay would be the power feed for the pump. The engine computer signals the relay on for 2 seconds with key on to prime the system, also signals during engine cranking.
Hello It sounds like a glogged fuel filter or throttle body problem. Disconnect gas line at carb get a small jar or can to catch gas, hold gas line in jar and have someone crank engine, If you have good gas flow to carb then Its a throtle body problem, (Throtle body and carb are same thing just in case you did not know)could be electrical or mechanical problem at throttle body, Its usually electrical, fuel flow meter. Hope this helps
you need to sort out if fuel or spaark issue. Can you hear fuel pump in gas tank run for 5 seconds when you turn the key to ON? Spray a burst of starting fluid into the throttle body or bgi air intake hose and see if it starts for a few seconds. If yes, then you have a fuel issue, maybe need a pump. Need to drop the tank to do that though. Check for 40 psi of pressure first.
If not, then it could be no spark. bad crank sensor, cam sensor, etc.
Is the yellow check engine light on too? If yes, get codes to find cause.
I would suggest starting with the less expensive solutions first. If you pull the air intake hose off the throttle body and open the throttle with the engine off look down inside if it is black try spraying it out with throttle body cleaner make sure to spray it out good. Afterwards start it you may have to keep your foot on the gas for a few minutes to make sure it doesn't stall then take your foot off the gas pedal and see if it stays running if it does your throttle body just needed cleaned. Note do not use carb cleaner use throttle body cleaner only, carb cleaner can damage the sensor in your throttle body.
If it runs o.k. until you let off the gas pedal, I'd take a few minutes & remove the AIS,or IAC motor (same thing) and spray it well with throttle body spray cleaner, especially pintle (pointed part) and the port (hole) it comes out of on throttle body, and then replace it & try that. If it cures it for a while & then starts to do it again, replace it.
One of the biggest problems I see that causes this is coking in the throttle body throat.It is easy to fix. Remove the air intake tube from the body, get you some B-12 spray cleaner from your local parts house and a shop rag. Wet the rag good, push the throttle open and wipe out all the black coking you see. You can spray some of the cleaner into the throttle body but if you use too much you could foul the plugs or hydro-lock the engine so again, if you spray it into the body, don't use too much.
take your distributor cap off and check the ignition module for loose wires or even a ground strap thats connected to the engine to the body , you can take the module to autozone and have it checked for free, it might have a crank position sensor thats going wacky
I would check and see if this is your fuel pump. Spray starting fluid in the throttle body right underneath the air horn and if its starts it's your fuel pump. Try turning your key three times but do not start it the first two times and your third time let it cycle for a second then turn the key to start. If it starts during one of these tests it's your fuel pump. Of course check battery and cables, plugs and wires, fuel in the tank, and starter. Autozone offers free tests on your electrical system. I hope this works for you!