I have a '93 MGM, currently the car will not start. Fuel pump is operational, fuel filter has been replaced. My next step is to change the plugs and maybe wires, I need to get this done regardless of solving the problem.

What is needed to change(when I pulled the plug I realized there is some distance to plug)?

What should I be careful of(I've heard horror stories about certain 4.6L and all 5.4L)?

I am eventually going to do a complete tune up, what else should I change in the process?

TIA, Tim

 

sounds almost like a TFI module like girlfriends son's car had issue with. i dont know much about the 4.6, but i know of 2 others who will chime in and let ya know for sure...

 

Got the car started for now, but it sputters and hesitates. Sounds like the TFI would be the place to start then work my way out, going back out to try and locate.

 

TFI can be pricey... try the plugs and wires first.... my 1987 Grand Marquis would crank forever before starting when i got it. did a tune-up, fuel filter and start almost immediately with a bump of the key... have you checked for vacuum leaks on the car?

 

Plugs wires and filters are a good place to start, especially if it needs them anyway.. A new PCV valve never hurts anything.. That's about it for a tune up on these..

For changing the plugs I use a standard spark plug socket, and tape it to an extension so that the socket doesn;t fall off down in there... (one million 6 uses for duct tape) Have a magnet on hand in case any of the plugs decide not to stick in the socket to come out... If you have acces to compressed air, blow all the spark plug holes out before removing the plugs.. Just in case there s any crap down in there. A good shop vac could do about the same thing too..

Make sure the engine is cold, and if any of the plugs seem extra hard to screw out spray some PB Blaster (or some sort of penetrating oil) down in there and let it soak a bit.. Work the plug a in both directions as you screw it out (ex: screw it out a half turn, back in a quarter turn) DOn;t force the plugs out as you do run the risk of buggering the threads..

For installing I have an old plug wire boot that's straight (not from a 4.6 though) with the wire pulled out and a log bolt screwed into the hole where the wire used to go.. Makes it nice for getting them started... A bit of never sieze on the threads never hurts a thing... Compare your old and new plugs, especially the length of the threads.. Some had about a half inch of threads, other's had about 3/4"... Gennerally the pre '96 cars use the shorter reach plug and the post use the longer reach, but not always so double check!

Since those wires have those crazy ling boots I like using the dielectrick grease on them both to help seal, and make them easier to remove the next time.. A dab in side the very end where it snaps on the plug, and a little smeared around the top where it seals against the head and you'll be golden..

Check thorougly for vac leaks (especially around the PCV plumbing).. Any air getting into the engine that does not pass through the air flow sensor well cause problems.. Inspect the plumbing for the breather and between the airflow sensor and throttle body too... The 4.6 did away with the TFI but still has an EDIS (electronic distributorless ignition system) module.. It's sort of mounted above the brake booser.. Generally when these crap out the car will have no spark, and it's fairly rare for them to crap out...

Was your check engine light on when you had the car running?

 

Check engine light was not on all the time but was coming on, also I can hear a thumping type noise from the left side when I try to give it fuel to get past the problem RPMs.

Picked up plugs and PCV today, but got sidetracked on the way home. Going to try fixing it up tomorrow.

 

Did you buy the car like this, or did it sit for a while, or?

 

rare occurance when i bought it, but once I started driving it daily it got more noticeable. both times that I was unable to start the car was after sitting after longer period of use, first time was after a day of running around grocery shopping second time after running 100km on highway

 

Might get the battery tested. a heat induced weak cell in a battery can be a hard bugger to track down.

 

Let me get this straight. When you say the car won't start, does it just turn over, or the starter doesn't engage at all? If it does turn over, is it weak? If not, does it click?