Why does my truck shake like crazy when its in idle?
 

If i run my truck for a little while and sit in idle it shakes, if i give it gas while im at idle it shakes less, my check engine light is on and when it shakes bad the light blinks then stops blinking and stays solid. Any ideas?? Thanks

Welcome to the forum
Need more info.....truck, motor "etc"
Did you just do a tune-up and cross some wires maybe? or hasn't it been tuned-up in a long time? Is it making any odd noises? Describe everything as best you can.

Did the check engine light come on at the time it started shaking or was it on before. Reading the codes will tell you why the light is on and point you in a direction to fix it.
Here is some info on the codes>

https://www.ford-trucks.com/article/...rocedures.html

Give more info and you'll get a lot of ideas and answers.......Good Luck

1996 Ford F150 V 6, Just Had It Tuned Up Because I Drove It Cross Country Last Summer, Its Got A Lot Of Miles On It, Over 190k, The Check Engine Light Has Been On For A While, Went Off For A Bit When I Changed My O2 Sensors, But It Came Back On Like A Week Later. Also Changed The Motor Mounts, And Had A New Tranny Put In Less Than 5k Miles Ago. The Truck Shakes Like Crazy When I Am Sitting At A Red Light Or A Stop Sign Ect, When Its Moving Its Fine Just When I Am Sitting Still Goin Nowere. As Long As I Give It A Little Gas And Keep The Rpm's Up It Doesnt Shake As Bad, But Its Gettin Terrible Gas Mileage And Need To Fix It With These Friggin Gas Prices.

Thanks

A flashing MIL may indicate a misfire. I know on my 2003 Ford Crown Vic when I had a bad coil pack, the MIL was flashing which is a BAD thing. The next thing to follow is clogged cats or cat depending on the vehicle.

Since you say it's idling rough, that could be a sure sign of a misfire. When you say tune-up, was it cap/rotor, wires, and new plugs? Did it run bad before the tune-up? I'd get the codes scanned. Hopefully it's nothing serious, but it could be a weak cylinder, clogged cat, bad injector, bad plug wires, weak coil, etc.

Motor mounts bad maybe?

you need to read the codes.

get the codes and I would check the EGR among other things. what all was included in the tune up?

Don't buy any parts until you check for codes.