sluggish 94 lx

[foxvalley48]

hi,
my son has a 1994 thunderbird lx that has a few issues.
the only things that work on the dash are the tach, speedometer, and low fuel light. (some other "lights" work as well but the previous owner had a custom sound system and totally screwed up the dash)

the main issue is that when the accelerator is depressed, the engine ALWAYS loses rpm's for a second or 2. it doesn't matter is you slowly depress the gas or "punch " it. for atleast 1 second she almost always stall before theres and pickup. if slowly depressed, 0 to 60 can be done reasonably well (except for the 1 second hesitation).
if "floored" she'll just sit and "chug a bit, maybe backfire untill you know you should stop doing what your doing (flooring it)

my experiance has been pre computer (like 63-64 chevy's mostly)

would like to help the boy out as he wants to restore/ repaint etc and have a "nice" ride

btw he has the 4.6l v-8, and are there really 8 injectors on this car? that's what it looks like



Jim

[overl0rd]

Yes, there are 8 injectors, one per cylinder. The intake is dry up to just before the intake to head union.

When was the last tune up? If it's had one done was it done with the proper parts? The 4.6 likes good platinum plugs, I ran autolites in mine, motorcrafts are fine too. Has the fuel filter been replaced?

If all of that is kosher, I'd look at the mass airflow sensor or the throttle position sensor.

[intrcptrbird]

I vote throttle position sensor. Also a good MAF cleaning is easy and can hlp too.

[foxvalley48]

yes tune up w/ proper parts about 7 months ago.any way to check the tps ? (without having to get a breakout box) or if absolutely required where to get one reasonably?


thanks all
Jim

[overl0rd]

Use a multimeter to check output voltage, measured between the gray/red and gray/white wires it should be putting out .5 volt throttle closed and 4.25 at WOT (+-3%). You can find an article on cleaning the MAF sensor on the following page. http://www.tccoa.com/articles/intake/index.html

[foxvalley48]

Thanks for all the info !
will try the tps first, was talking with my son and at the price of the tps sensor (about 35.00) he said go for it so we will just change it. (it is the original).

on a second issue. the last owner had a "custom sound and alarm system"

he patched into the dashboard wires and it appears that only the speedometer, tach , low fuel, check engine, air bag etc work properly.
the ampmeter, oil pressure etc do not work right. sometimes the "needles" point opposite of where they should be . i mean a full 180 degrees out.

it only appears that the gauges do this. anyplace to get a simple wiring diag of the dash?



thanks for all your help

Jim

[97Bird]

Check at your local library for the Mitchell electrical manual for your year 'Bird. I posted where to buy factory shop and electrical manuals in the Tech Help thread at the top of the main forum page.