I hope some one can help!!! Have developed a rough idle and some roughness at open throttle ( small vibration) on my Sig 240. Also have found that I am getting a lean fire on plugs 1,5,6,and 7.Here is what I have had done so far.
1. Had tune up done (new plugs, rotor ,distributor cap.) Checked timing.
2. Replaced Fuel filter and checked fuel for bad fuel .
3. Checked fuel pump pressure (ok)
4. Replace Throttle body mounting plate and TB gasket.
5. checked cylinder compression. ( all cylinders at 173 or above compression)
6. Sprayed ether on intake , throttle body, no leaks
7. Checked for codes (no failure codes)
8. Replaced all plugs and ran engine. (same cylinders running lean)
9. Checked spark at plugs with light tester all plugs getting good spark
10 Checked crankshaft sensor (ok)
11.Checked MAP sensor (ok)
12 Cleaned IAC
13 Fuel injectors throwing nice cone shape and functioning properly
All of the above has been done by certified mechanic. They are at a loss as to what is causing this. Hoping someone might have an idea of what might be causing this.
Sorry for the long post !!!!!
1. Had tune up done (new plugs, rotor ,distributor cap.) Checked timing.
2. Replaced Fuel filter and checked fuel for bad fuel .
3. Checked fuel pump pressure (ok)
4. Replace Throttle body mounting plate and TB gasket.
5. checked cylinder compression. ( all cylinders at 173 or above compression)
6. Sprayed ether on intake , throttle body, no leaks
7. Checked for codes (no failure codes)
8. Replaced all plugs and ran engine. (same cylinders running lean)
9. Checked spark at plugs with light tester all plugs getting good spark
10 Checked crankshaft sensor (ok)
11.Checked MAP sensor (ok)
12 Cleaned IAC
13 Fuel injectors throwing nice cone shape and functioning properly
All of the above has been done by certified mechanic. They are at a loss as to what is causing this. Hoping someone might have an idea of what might be causing this.
Sorry for the long post !!!!!