Rough idle

[Harry]

this is for an expy 03 4.6

so this week the truck started idle rough. like it was gonna stall. but it keeps running. i replaced the IAC last year when it had the same symptoms and it fixed it. but now its back again. any advice on where to look. thank you

 

[riphip]

Look at VACUUM LINES FIRST. Easiest/cheapest thing to check and replace. Age,miles and heat deteriorate the rubber and causes leaks. PCV lines also (vacuum)

 

[Harry]

Look at VACUUM LINES FIRST. Easiest/cheapest thing to check and replace. Age,miles and heat deteriorate the rubber and causes leaks. PCV lines also (vacuum)

where do i find the PCV LINE? i also disocvered a leaky radiator hose. which i will replace

 

[riphip]

Ck passenger side valve cover. Remove battery & check hose (vac) attached to vac reservoir, etc.

I knew all of mine needed replacing so I pulled the plug and did them all. Rockauto.com

 

[Harry]

Ck passenger side valve cover. Remove battery & check hose (vac) attached to vac reservoir, etc.

I knew all of mine needed replacing so I pulled the plug and did them all. Rockauto.com

thank you!

 

[riphip]

You are more than welcome. Vacuum lines can be so problematic after mileage, years and heat under he hood, Found that out on my antique Ford diesel trucks. Check also for moisture/cooling fluids in spark plug areas. The repairs are just hard to get to areas at times. Love my 2004

 

[riphip]

PVC is the BLUE Thing in valve cover with hose mounted

 

[Hamfisted]

The best method to find vacuum leaks is with a smoke machine. You need a compressor or air tank to provide air flow to the smoke machine.

https://www.ebay.com/itm/EVAP-Smoke...40ac91d0973449d9205d|ampid:PL_CLK|clp:2334524

 

[Harry]

The best method to find vacuum leaks is with a smoke machine. You need a compressor or air tank to provide air flow to the smoke machine.

https://www.ebay.com/itm/EVAP-Smoke-Machine-Automotive-Vacuum-Diagnostic-Leak-Detection-Tester-Adapters/283125920686?epid=22023111244&_trkparms=ispr=1&hash=item41eb9eb3ae:g:WycAAOSwUUJficfZ&amdata=enc:AQAFAAACcBaobrjLl8XobRIiIML1V4Imu%2Fn%2BzU5L90Z278x5ickk7PdDazAlGltMLJlUhrWsD6YH3UcxI0bljDKSzGpSIngr5tUsDbnDpV1YkUafLs4RwaPQg%2BEZuaIZyh64UwPAE3gdvDa1vw3m%2FfDDEIpswS1Eeam4%2F79Qj4eBwtKefcFcboWZD7DTELzM3WPNBqRq0XfXJbCsy6B90TabhEE13YkuS1QvOTVqlUUlNDi8tfnBPOT4d314gC7ZBQQLPkHgny0RTfGLqnzhELisimU1t8YUkxju%2FVlNaH0pk3N2imSApGpdP%2FgmV8g1vFto%2F2TF0jQkxaCQDpcRlfRWYKwFcioHn102GIEMW00XDxYus3vSdUsYkJd6Gk5uj0IU5ny8GROkVgAQR21%2FUbnaswKO2LdyGnGxGyTPXN3Uj2LDkPNBAknrJ7%2B9Jzu%2FMYnT7k4KTOCxvYqq01oVqFcyolQa%2FTZs%2FJZhHaxZPqb2Wr8kKI7Uml6r2Ptq4W%2FKT5OUjWfYgpGYGY0pdHLz4sXsey7OkiqdhVVpJm0OE0EEOkc%2FiAJldy%2FRywup4AkOTn0NhGukW0cU33vt0r%2B2wrET0BESGXQMAXM3ASTWb%2Btq1ohqkUzm%2B3taTSZI9W7Agskc3lnhkrvOPYCEmrj3P4ZFLvNalBcN5ZIYp%2BuThgnSBb7M8VTrb8svMX7b%2BbIBQ8FoBd1EMFH80%2BbA%2BdT8z6hEGUPmjBV3QovE7C3m23gFed%2FhYZmpvwGliu1gpF7hbS33uw9v6Ugu7D4ZJFWSVCpoJ5LzH3ZF4O%2BCelqw0DKenzUq02n3b1kLVXEJLHAAk58O0U318w%3D%3D|cksum:28312592068672d7d6b012e240ac91d0973449d9205d|ampidL_CLK|clp:2334524

whay if i blow cigarette smlke in it?

 

[Harry]

one more thing. where would i find the throttle positioning sensor?