sipynsyrup

Well for the past 2 months my car has been running horribly and I have asked on here a few times what I should do and still haven't figured it out.

When accelerating after first starting the car its like no matter how much gas I give it and slip the clutch it almost dies out everytime and feels like it loads the motor down(rich). If I give it WOT it clears everything up and takes off fine, but the problem is only under light acceleration. I thought it was just when car runs cold(a lot more obvious), but if I sit at a light for a while it and take off slowly it does it again. Stop signs(after engine atleast 150F) the car runs fine. Whenever I feel it bogging down if I give it more gas it bogs down more(unless I punch it) then it will backfire(pops under the seat around where the cats are). Sometimes when it starts loading the motor and i keep the gas pedal steady it takes a second and then my car takes off like I just gave it gas. I have only had cats on my car for almost a year for emissions and my EGR has been blocked off for over 4 years.

Codes: It did throw a code for right 02 sensor being lean and I replaced the o2 and it stopped throwing the code but the problem was still there!

replaced:

-both 02 sensors
-plugs, wires, cap, coil
-cleaned MAF
-cleaned throttle body from the intake side(sprayed cleaner in there and cleaned as much as I could with a rag) also cleaned the IAC
-Ran seafoam


Also, the other day I came to a stop with the clutch fully engaged and my engine slowly started revving on its own. It revved reallly slow, but got up to about 1100 rpms..... it did this twice in the last month and has turned the car off before on me too like the clutch wasn't engaged.

I followed the vacuum hoses and didn't see any obvious vacuum leaks. I dont have a fuel pressure gauge to check fp.


Any suggestions??? This car is my DD

cammedlx

To tell you the truth it really sounds like there is a vacuum leak somewhere to me, are you sure that it isn't backfiring through the intake? The easiest way to find a vacuum leak would be go to your local autoparts store and pick up a couple cans of carb cleaner. Then you will want to start your car and spray every possible place where there could be a vacuum leak "lower intake,upper intake,all the vacuum lines under the upper intake,etc.." If there is a notecible difference in the idle when you spray a certain place then you will know where to look to find the vacuum leak.

mattdel

doesn't sound like a vacuum leak at all. sounds like a plugged cat or possible bad MAF. rip the Hpipe out and run it around the block open header for a few minutes, see if the problem is completely gone.

if you happen to have a catless hpipe laying around, a swap is less of a fire hazard

redpony88

this is the EXACT same thing that happens to me, i have a off road H on my car so it cant be a clogged cat. i'm thinking it may be the o2 sensors as a small issue on mine but my main concern is the MAF, i just dont wanna go out and buy a new MAF and have that not be the right part.....

lx5.0

i had the same issue i would get the codes for my 02 sensors being lean so i replaced one of them that looked bad and didnt fix issue then i checked my volts on tps and i had it around somewhere in the 90's so i lowered to like .87 and my car ran fine ever since. Its like if everytime i increased the volts on tps to somewhere in the 90's my car would jerk badly at cruizin speeds and would always have to be giving it gas so it wont jerk

sipynsyrup

no clue. It could be clogged cats and I need them cutout anyways. Tomorrow I will check again with carb cleaner for a vacuum leak. I will probably go borrow a meter to check voltage on tps also.

Ill get back with you guys tomorrow.

Night Terror

MY car does the same **** also...

when its cold it will hesitate and make popping noises... somtimes WOT won't work, i just lay half way on the pedal, let it pop and after that it doesn't really do it again.

cammedlx

Yeah 10-4 there...It could be a bad maf sensor but i've never see a car lean backfire or through the exhaust from one ever.Stopped up cat the car would have not power all the time not just from time to time. Vacuum leak will cause lean pops through the intake cause the car to throw lean codes,affect idle and can cause mifire issues. So just let us know what you find out im sure with all the "mechanics around here" someone will figure it out.

sipynsyrup

ok been really busy this weekend so I didnt have time to disconnect the exhaust to check for cat bein clogged, but I did buy a voltmeter and check the voltage on the tbs. It was at 1.021

I lowered it down to about .996 the first time then test drove it. It started up fast(usually takes a few cranks) and took off fine and ran normal until I got about 5 blocks and started speeding up on a county road it started the same thing. I turned around and came back. Checked the voltage again but it went up... dunno why.. guess because the engine was warmed up? Well I set it this time to .986 and just drove it around 2-3 blocks. Seemed fine, but I am unsure.

How do you know if you have a bad sensor???

Should I check MAF voltage?

aode08

Sounds like your car may have had a HCI(Heads Cam Intake) done, give us a picture of your engine bay. And for you not to know this worries me, expecially with it not listed in your sig.


2. You may be running rich and smelling fuel from a spark blowout issue or too high of fuel pressure setting/ignition issue as well.


We will start here,

1.Buy a fuel pressure guage from autozone $20, and check the reading.

2. Using a timing light $25 Autozone or Harbor Freight, check base timing with spout unplugged that goes to dizzy.

3. Look for the orange O2 sensor ground wire on the firewall, make sure its not undone, rusted or missing off the firewall or head on the driver side. And make sure that silver looking ground strap is there as applicable.



also I think the 1994 has the ECM which performs best with a tune after a HCI and mods, if you feel unconfident, take it to the a reputable Mustang Performance Shop, this stuff can get real technical.