My 90 Silverado 5.7L 350 runs rough at idle and under light acceleration. I did a basic tune-up including plugs, wires, cap & rotor, and throttle body cleaning. The coil is fine. Check engine light comes on intermittently. Does anyone know of any common problems with this vehicle that causes this condition? Thanks.
2007-07-06 14:56:03 · 12 answers · asked by john s 1 in Cars & Transportation ➔ Car Makes ➔ Chevrolet
All quality, name brand parts were used. Spark plug gap was set to spec. No vacuum leaks were found.
2007-07-06 15:05:05 · update #1
Along with running rough, the truck is also difficult to start, at hot or cold temp. The condition was present before doing the tune up. Gut feeling is telling me it is a sensor, but I'm clueless as to which one it might be.
2007-07-06 15:10:59 · update #2
Did you double check the gapping of your plugs? Also did you buy your plugs from Wal-mart? If so you might have a misfiring plug. Wal-Mart specializes in selling rebuilt plugs. My suggestion is if this is the problem, repurchase your plugs and wires from a respectible auto parts place.
2007-07-06 15:00:25 · answer #1 · answered by hardcoredlw 5 · 0⤊ 0⤋
In the early 90's GM had a big problem with egr valves. The spring in them would get weak and the back pressure in the exhaust would open the EGR valve. Also they would actually wear out similar to a valve guide in the cylinder head would and the pintle would not sit correctly on the seat creating a leak and a hard starting issue.
2007-07-06 19:08:05 · answer #2 · answered by fasttoysmullen 2 · 0⤊ 0⤋
Also you might want to check your timing and retime your engine. You will need a timing light to get an accurate timing. How did your spark plugs look, if they looked a little weird or out of shaped you could have a misfire and check the gap of your sparkplug and make sure its correct.
2007-07-06 15:06:45 · answer #3 · answered by wtf? 2 · 0⤊ 0⤋
It could be a fuel problem, too. Try adding a bottle of fuel cleaner or injection cleaner in the gas tank. There is always a possibility of water in the fuel. It's a cheap fix,too.
2007-07-06 18:20:59 · answer #4 · answered by randyrich 5 · 0⤊ 0⤋
It feels like your timing is off i'd attempt and set the timing bypass andpersistent it and notice if nevertheless acts up and if it does recheck the timing and notice if it moved returned. If it did you will elect a clean disturber shaft. The pickup is breaking aside. I had a similar subject on my ninety two.
2016-09-29 05:52:58 · answer #5 · answered by ? 4 · 0⤊ 0⤋
Also, check for leaks at the throttle body gasket.
2007-07-07 22:51:06 · answer #6 · answered by ssrz71 2 · 0⤊ 0⤋
Check the transmission sometimes, the transmission filter and gasket needs to be changed
2007-07-08 17:02:23 · answer #7 · answered by Dan 4 · 0⤊ 0⤋
I would start checking for loose or damaged vacuum hoses, this is the most obvious first step.
2007-07-06 15:01:57 · answer #8 · answered by htrdce69 2 · 0⤊ 0⤋
Sounds like you need to have the fuel filter replaced.If it does not run better have the fuel pressure tested.
2007-07-06 17:17:51 · answer #9 · answered by HyperGforce 7 · 0⤊ 0⤋
Clean the pintle on the EGR valve.
2007-07-06 15:28:24 · answer #10 · answered by gdwrnch40 6 · 0⤊ 0⤋