More problems with car, combined with TPS adjustment, need advice

[281pony]

i just took a small bit of the material off. put it back on, did another test and its JUST below 1 volt on the analog. so its about perfect.

i drove the car, it runs and pulls ok but something still isint right. ive got the no responce to throttle again, but not as bad.

it only happens when its just the weight of my foot resting on the pedal. hardly any throttle applied, if i give it anymore throttle it kicks back in also driving along at 1500 rpm i can feel it missing. it feels like someone is applying a brake as its rolling, then letting off, applying again.

not enough to slow the car down really, but it is noticable. idle is fine, power seems ok now.

could that be in relation to my fuel pump cicuit code i got? sorry for so many questions.

 

[281pony]

bump..

also to clarify my throttle responce and idle is fine. it is responsive except at idle. i push it real quick and it huffs then revs to about 2k. doesnt seem to be revving quite like it should.

when im driving it is responsive also, but probably not as much as it should be. my idle is better. i can come up to lights, push in clutch and apply brake. it drops to about 500 rpm and my lights dim for a brief second then returns. with tps at approximately .99 volts

it has the no responce part mostly just into the gear and starting to rev out. let out the clutch, and im just barely giving it gas like always driving normally. your just coasting all the sudden, you can either keep your foot in the same place and wait 2-3 seconds and it starts responding again, or push the gas a little more and it stops

when it isint doing that. my cruising rpm is usually 1500 in every gear. the only gears i feel it in are third/fourth, ocassional fifth. although i never cruise at 1500 in second. its just driving along fine, same gas being applied. then you can feel the car almost hesitating. it is quick hesitations, then its normal, then it feels like the brakes are tapped again its like it cant stand to stay at the same rpm. you go just over that rpm or under and it doesnt do it. then you come back to a consistant rpm (always around 1500) and its back.

does this sound fuel pump related? coil related? i was only pulling the fuel circuit code, and the tps. the tps is within the right range now. i have had this weird hesitation around 1500 rpm for awhile now. before it was in fifth gear only, ocassional fourth. now it is mainly third/fourth. a new fuel filter stopped it twice now for about 1 week this time, and about a month last time. the fuel filter was just put in a few hundred miles ago, if that. maybe a weak fuel pump?

sorry if i covered stuff over again. just want to get to the bottom of this.

 

[HISSIN50]

i might miss some stuff now - this thread (and your last one) are cumulatively long.
so bear with me.

did you disconnect the battery after resetting the TPS? leave it disconnected for a bit or turn on the headlights with the battery disconnected - to discharge the puter's KAM (turn headlights back off before reconnecting the battery).

i would do this, drive it, and repull codes. i cant remember if you know what your vac reading is? a vac leak can cause hesitation, but it usually leaves a hanging idle when returning (i.e. slow to rev down when coming to a light).

also, clean the IAC (for low idle return problems. the VSS and IAC are supposed to hold the idle at ~1500 RPM when no gas is applied and the vehicle is still rolling). here is a link someone earlier posted on another thread. i glanced at it and it seemed pretty thorough.

http://www.muscularmustangs.com/iac.html

good luck.

 

[281pony]

i didnt disconnect my battery after doing the tps. i will do that and go for a drive and get it all the way up to temp.

my iac and vss are clean. i dont believe i have any air leaks, it drops just fine. how can i check the vac pressure? i dont have any readings for that.

do you think that this code 95 is coming into play? it says code 95 " fuel pump secondary cicuit fault "

everything except the tps in my engine bay has always checked out ok. i am kind of leaning towards my fuel pump, but im an idiot compared to alot of people on this site

ill get a vac reading once i learn what that is all about, going out to disconnect the battery right now. ill leave it off for 30 min, then do the headlights and go out for a drive.

 

[HISSIN50]

to check vacuum, find the vac tree on the driver firewall. there might be an unused port (my 88GT has one). put a gauge on it - a stockish motor will make 15-20 inches at idle (~800 rpm). not sure if you have a cam - if so that might be a bit optimistic depending upon how much overlap, etc you have.

code 95 is FP circuit or air injection problem right? if so, or you have doubts (i would), i would check both out. for FP, i would hook up a gauge and see what gives. the times when FP demand is up, you seem to be fine (this seems like an engine management issue to me). i would jump on the air diverter aspect though.

you have enough symptoms going on that it could be many things (we, or i, tend to get on a roll with one thing and lose perspective). your timing is spot on, right?

ok, nuff for another post.

 

[281pony]

i read the link you gave me. im going to re-clean the iac and vss.

i have a good symptom for this kind of. the mass air meter. i have a pro-m one, calibrated for 19#'s. this weird hesitation/no throttle came into play right after i found all the dirt and crap in my tb (which im going to clean also

i cant get the meter off to clean it because t has some weird ass screws. its like a starr pattern, but it has a little point in the center of it. im going to try cleaning my mass air meter since it said right on there, excessive K&N fluid and dirt can cause loss of power, hesitation. i had alot of dirt in there with an unoiled filter, and i used a fair amount of oil.

so im attempting to clean that, going to clean the tb and iac also. ill be back in 30 min with another issue, i mean. a fixed car hopefully

 

[HISSIN50]

sounds good. im foggy on the MAF stuff cuz im still SD. the funny fasteners are torx bits. if they have a dot in the middle, they are tamper proof torx bits. i would not undo those but just pop the tube off and spray some electrical contact cleaner on the wire - dont break the wire.

the air filter oil issue is a very common one from what i read.

for the TB cleaning, i might use a cleaner approved for throttle bodies - stangs come with a teflon coating in there - some carb type cleaners can remove that coating.

good luck - let us know how it goes.

 

[281pony]

**** pro-m. it is 300 dollars (i paid 200 on sale) for a plastic maf unit anyways. then you cant take the screws out?

i dont have the bits, and im sick of ****ing this this cursed car. ill remove the pos airfilter it comes with and see if i can spray some cleaner in there.

 

[HISSIN50]

**** pro-m. it is 300 dollars (i paid 200 on sale) for a plastic maf unit anyways. then you cant take the screws out?

i dont have the bits, and im sick of ****ing this this cursed car. ill remove the pos airfilter it comes with and see if i can spray some cleaner in there.

you can take the fasteners out - you just need a tamper proof torx bit to do it.

if you can, what i would do: get at the meter from the inlet or outlet side and just spray the wire down. less hassle or chance of something going wrong. the MAF guys will know a lot more than i do on this - that is how i would do it though.

good luck.

 

[281pony]

just got done with it.

took the airfilter section off, and sprayed down the inlet a few times. got it sprayed down pretty well, so hopefully if anything it cleaned it. i have a ton of extra k&n airfilter oil still damp on the airfilter after like a week ago i sprayed it.

it is blocking the dirt now to my inlet tube. i cleaned the iac, cleaned the throttle body, lubed the butterfly, i think that is it. put it all back together, unhooked the negative battery.

going to let it sit for 30 minutes disconnected, then do the headlight part, and go for a drive. got my fingers crossed it fixes something or gives me my missing power.

not alot, but some dirt came out of the iac, the tb had minor carbon since i cleaned it partially last time i looked, and the mass air sensor i dont know. i sprayed the first shot and it went right into cuts on my hand so i jerked away and got a rag.

thanks for another nights help hissin

 

[HISSIN50]

so how is it doing now? if poor, try pulling codes again (now that the KAM has reset).

good luck.

 

[281pony]

i have it narrowed down one more step now, i made another post.

if you want to check it out, let me know your opinion