Rough engine after intake manifold replacement

Asked by Mar 02, 2015 at 12:53 AM about the 1999 Mercury Grand Marquis 4 Dr GS Sedan

Question type: Maintenance & Repair

I just replaced the intake manifold on my 99 Grand Marquis GS and it is now running rough.   OBD shows no codes.  I did it again and still no codes.  While removing the fuel rail a couple of the injectors came off but I put them back on with ease.  Any ideas?

2 Answers

223,055

Make sure you didn't cross any spark plug wires. Maybe replace the rubber O-rings on the fuel injectors so they seat in tighter?

340

Kind hard to do but make you hooked the right injector electrical plugs into the right injectors.

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