1989 Chevy Silverado sputters when cold on acceleration.
I have a 1989 Chevy C1500 Silverado with a 5.7, 350 engine. I has about 380000 miles on it so it's just getting broke in, lol. I did a tune up on it about 6 months, 6000 miles ago. Plugs, plug wires, distributor cap and rotor, fuel filter, pvc valve, and fuel pump( gas gauge has been inaccurate for years so I put a new pump and float in). The other day when I was leaving work I noticed the engine hesitating and kid of sputtering when I was accelerating, I would let of the gas and it would stop but I had to slowly increase the accleration to stop the sputtering. After the truck was at operating temp all was fine with no sputtering or hesitation. I though I might have gotten some bad gas or something so I replaced the fuel filter and ran some chevron tech cleaner in the tank when i filled up yesterday. I checked the cap and rotor just to be sure it wasn't cracked or anything and it looks good. It almost seems like I have fouled plugs and they unfoul after they run for a bit. But it idles fine on start up.
check engine light happen to be on? I would suggest also to check your fuel pressure. I've seen bad ones right out of the box before
No check engine light. But if the pump was the culprete wouldn't it do it if the engine was hot or cold?
im thinking of the regulator too. When its cold it runs off a base fuel trim. Once it warms up it will adjust and compensate. If your pressure is a little off, it might be able to compensate for it once warm but not when cold. It also may just be time to freshen up the engine. 380,000 miles is alot, she could just have low compression
I'll give that a check. I was thinking of doing a compression check also to see how she is doing with wear and tear. I did freshen her up about 100000 miles ago.
I have the same truck one year older and I am having the same problems. My truck however only has 150000 miles on it. Did you find a solution? or can anyone think of other possible problems. I have already changed the plugs and wires, fuel filter, pump is like a year old, rotor and distributor cap new as well.
I'm going to say like before. Have your fuel pressure tested. Also this just happened to me, bought a truck that was doing the same thing and the fuel filter was on backwards. Yes it makes a difference. If it is on backwards DO NOT just turn it around. Get a new one
There is also a pressure regulator in your throttle body. A good tbi rebuild isn't bad to do
Thanks for the follow up but this question was posted so long ago I had forgotten to update it. I checked fuel pressures and compression, both were ok. I bought a TB rebuild kit and was getting ready to pull it and rebuild it but decided to wait . When I pulled all the plugs for compression testing I checked for any thing that looked unusual like a crack or something that may be affected by the heat as the engine warms up. Just for peace of mind I put new plugs in even though these only had about 5 or 6000 on them. Truck has ran beautiful ever since. Now at about 392000 miles and still running strong...Must have had a bad new plug....
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