Car running weird, pulled codes, now confused

[281pony]

ok i've kind of had an ongoing problem with my car and im sick of it. some things have helped, but nothing substancial or consistant.

my car seriously lacks lowend, and it isint revving like it should in the upper rpm's even. first gear doesnt even snap anymore, i tap the pedal like i used to and it almost hesitates for a second, then slowly revs. first gear floored rev's like third should.

i have all the mods in my sig. i pulled my codes, and im getting 3 that are worth questioning. 2 are from smog pump that is disconnected

23- Throttle Position sensor signal out of range.

how do i adjust that on an 88? i have a chilton for an 89+, and it tells you how to measure volts, ect.. but it is a different setup on my 88.

67- Neutral drive switch circuit failure, circuit open.

lastly, 95- Fuel pump secondary circuit fault.

has anyone had these codes/issues before? would the TPS completely throw off my lowend power and revving as bad as im experiencing?

thanks for any help. would like to get this fixed before i install my new heads.

 

[281pony]

forgot to mention

i have new plugs, plug wires, cap/rotor good, new fuel filter (which stopped a weird hesitaton/missing problem i had), fp is 38 with no vac, map line plugged, fixed the kinked line i had going to the back of my intake.

nothing made any difference in performance except for my mass air conversion. shifting into all gears at high rpm pulls harder then it did before. i can still be going at 2k in second and hammer it, feels slow and rev's slow. especially with 3:55's

 

[281pony]

anyone?

if i drive it and let the rpm wind out it is fine, but when i hammer it they hit like a barrier at 3500+ and rev really slow.

thats the only other thing ive concluded.

 

[HISSIN50]

how is your TPS different (my 88 GT vert is the same as all later models). i would check your base setting and use an analog meter to check that the potentiometer has a nice even sweep from ~1.0 volts to 4.5 ish volts. if there are breaks i would replace it.

also check the wiring - make sure the wires are not open. there is ground, the reference and signal. one wire is ground, one is ~4.5-5 volts and one reflects the change (1 -4.5 volts depending on how far the TPS is opened).

code 67 will pop up if you have the car in gear while doing the test (there is another reason too, but i cant remember).

i might check some basics - how is FP and vacuum (SD relying on vac so much). a stockish motor should put out 15-20 inches at idle.

good luck.

 

[281pony]

ill take a picture of it. the wiring of the tps and the positioning of it are different then chilton shows. my cousin had an 89 and he said it was weird too.

fp is 38 without vac. it is mass air converted now.

would the tps throw it off that much though? i mean i stomped second gear, it revved good to 3500, then it was like a snail to 4200 and i let off. with the pedal to the floor at 3500, it probably took 3-4 seconds to rev over to 4200. just stops flowing almost, does that even make sense?

lately it has been doing one other thing too. ill be driving along, and then the pedal like sticks almost, and i push it again, car doesnt respond. then all the sudden it kicks in almost like an automatic downshifting.

id just like my lowend power back, i feel like im driving a damn ranger not a mustang. going to get a pic of the tps for you

 

[HISSIN50]

if the TPS has a fault at the top end (dead spot), it could create some problems. five mins and a VOM will tell ya (once we get the wiring figured out ).

any vac leaks? it could be a lot of other things - coil comes to mind. ditto for fuel pressure (may or may not toss a code).

i would start with the TPS and vac and go from there, myself. others might have some better ideas for you though.

good luck.

 

[281pony]

ok. i dont have any vac leaks, ive listened, looked, felt, all is fine.

fp is 38 without vac, default setting i believe. timing is 10-12.

coil might be a possibility, i could buy a new one and try. im attaching a pic of my tps.