kenratboy Posted February 17, 2003 Share Posted February 17, 2003 Yes, it's off topic, but I'll see if anyone knows. I have a 1989 Chevy Silverado with a 350 SB in it. When I first start it, sometimes it runs pretty rough and the only way to correct it is to start driving it and give it some gas to get the RPM's up (not a lot.) It is a automatic, and it has actually STALLED on me. I backed out of the driveway, put it into D, gave it some gas (NOT hard, just nice and easy), it sputtered and died. I THINK it is a common problem and has to do with the choke, but any ideas? Thanks! Quote Link to comment Share on other sites More sharing options...
arfz28 Posted February 17, 2003 Share Posted February 17, 2003 Ratboy, the truck is fuel injected, it is probably an idle sensor, or some other fuel related senser most likly one the throdle body.Probably a simple fix that a shop can do in about a half an hour.Also could be a clogged fuel filter, doubt it thow.Just some ideas, I dont fix cars for a living, they have become to computer complecated. I still mess with my older Z28 thow. Quote Link to comment Share on other sites More sharing options...
michael hurd Posted February 18, 2003 Share Posted February 18, 2003 Two barrel rochester p.o.s throttle body injector unit. Yuck ! The very same unit that I have on my '93 caprice. First off, how many miles on the motor ? The egr valve (exhaust gas recirculation) valve located on the intake manifold likes to stick once in a while. If you pull up on the diaphragm by hand when the engine is running, then it should almost stall. If it does not return quickly when you let go, then it is problematic. Next, check the spray pattern of the injectors themselves with a timing light. Hook the inductive pickup on the coil wire so it pulses fast, and aim at the injectors spraying on the throttle plates. With a friend to put it into gear, then check the spray pattern. If the pattern is not cone shaped or looks like fuel is dripping, you have a problem. You need 15 lbs of fuel pressure for the system to work properly. Check that. Another problem that is prevalent in those systems is that the distributor pole piece magnet cracks. As the distributor spins, this results in timing errors that can cause erratic running. Not to mention bad grounds / connections etc. etc. A real bear to diagnose. E-mail me if you have more questions. Quote Link to comment Share on other sites More sharing options...
michael hurd Posted February 18, 2003 Share Posted February 18, 2003 I probably won't post or reply for a few days, got lots of work ahead of me. So if your e-mails get put off til the weekend, don't worry, I'll get to them kenratboy. Quote Link to comment Share on other sites More sharing options...
ricktate Posted February 18, 2003 Share Posted February 18, 2003 if it doesnt do it all the time i think it is temp. sensor...if it does it all the time maybe cap and rotor....check these first,,,,they are a cheap fix...wude wick,,,lol Quote Link to comment Share on other sites More sharing options...
kenratboy Posted February 18, 2003 Author Share Posted February 18, 2003 78,000 miles. Just had the intake manifold gasket replaced, along with the fuel filter. Everything else works fine. I will have to look at some of those suggestions. Thanks!!! Quote Link to comment Share on other sites More sharing options...
Soundthought Posted February 18, 2003 Share Posted February 18, 2003 Hi Ken. Maybe you have some water from condensation in your gas tank. If you run your tank fairly low all the time, it is a good possibility I would suggest trying a bottle of gas dry (Water remover) before anything else. Gas dryer with Isopropyl Alcohol is the best. As mentioned above, another thing to take a peek at is the distributor cap, itself. Visually inspect it for cracks. If it has even a hair line fissure in it, that could cause hesitation and stalling when cold. Just a thought. Good luck. John. Quote Link to comment Share on other sites More sharing options...
T2K Posted February 18, 2003 Share Posted February 18, 2003 Sounds like the EGR valve to me too. If you're using high octane gas, stop it. Use octane specified in manual. Go to your local NAPA store and buy some LUCAS UPPER CYLINDER LUBRICANT. It's good for what ail's ye! It works! If you find something else is causing the problem, use the LUCAS anyway. It's good for what ail's ye! Keith EDit> Oh yeah, does it run rough from a dead stop and smooth out about 1600 RPM? Give the LUCAS miracle elixir about 100 or so miles to work. It's good for what ail's ye! Quote Link to comment Share on other sites More sharing options...
Frzninvt Posted February 18, 2003 Share Posted February 18, 2003 A clogged or sticking PCV valve would have symptoms similar to what you have described. If that does not do it, when was the last time the O2 sensor was changed. Both of these things would impact idling and performance. Check the air filter as well make sure that is free of debris and air flows freely through it. Hopefully the spark plugs have been changed recently as well, and don't use Champion, they do not hold up. Just a few more suggestions. Quote Link to comment Share on other sites More sharing options...
T2K Posted February 18, 2003 Share Posted February 18, 2003 You could also try washing the truck and giving it a good hand polish/wax job. If that doesn't help, at least it will look good sitting on the side of the road. Just a suggestion. Keith Quote Link to comment Share on other sites More sharing options...
kenratboy Posted February 18, 2003 Author Share Posted February 18, 2003 ---------------- On 2/18/2003 2:42:20 PM talktoKeith wrote: You could also try washing the truck and giving it a good hand polish/wax job. If that doesn't help, at least it will look good sitting on the side of the road. Just a suggestion. Keith ---------------- After the first 30 seconds, it runs perfectly. NO other issues, it is just the issue at idle. Other than that, always fine. No matter how cold it is, it ALWAYS starts on the first try. Quote Link to comment Share on other sites More sharing options...
erikjohn Posted February 19, 2003 Share Posted February 19, 2003 Kenratboy, First and formost look in the engine compartment and make sure that everything that looks like it should be hooked up is. Sounds like either the choke or possibly a leaky gasket. Spray carb cleaner around the base of the carb and the the manifold where it meets the block. If it increases in RPM this means that there is a leak. Just carefully tighten the nuts a little to see if it will seal. Sometimes a small leak will cause it to quit when it is cold and give it a rough idle. The choke is a no brainer. Take of the air cleaner and start it. Look at the top of the carb to see if the choke is closing. If not it's the choke. Hope this helps. EJ Quote Link to comment Share on other sites More sharing options...
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