Ok I have a 1997 Mercury Grand Marquis LS. I''ve been looking on the at peoples 1/4 mile times with my car and them being stock . I''ve seen the times run from high 16s to low 16s. But when I went to the track last weekend with 87 octane gas and a reaction time of .825 I ran the 1/4 mile at 18.860 at 75mph[img]smileys/smiley5.gif[/img]. Before the race I changed the spark plugs because I have been getting the check engine lights and the code is either for bad spark plug or wires and its still on but I had a bad plug but the CE light remains on so I was planning on changing the wires and put in 91 octance this week and go to the track again this weekend to see if it runs any better. But any info or advice that may be making it run so slow?

 

If you''ve got a CEL for a cylinder misfire, I''d say 18.8 is a decent time for a seven cylinder.

I''d get the CEL problem fixed and re-run it before you do anything else. It also may not be the plug or wires causing the misfire. Could be a vacuum leak from a blown intake seal or a leaking injector or a bad coil pack, etc. etc..

 

Yea we got the plugs and wires fixed it ran good for a while then got worse (ran 19.3) so on tuesday were going to run a fuel pressure check because my uncle thinks its a plugged or bad injector because he said it idles and runs to go to be anything else but he said he can feel it misfire at WOT (I cant) the only way I can tell the difference is when I get in my moms 92 grand marquis and has a hell of a lot more power then mine

 

This is only an idea, try resetting your computer by disconnecting your battery terminal. Then, if your check engine light goes on then find out your problem. From there on you might codes from your CEL to inform you of problem. Also, if you go to Autozone they check your CEL codes for free. Hopes this worksand let us know your responds.

 

So, what was the fuel pressure?