After TFS h/c/i swap, car runs rich + stalling...

[Aliate X]

Hey guys, I just finished my TFS swap and the car is running very rich, it will burn a tank of gas in 1 day of normal driving. The car also does not like to idle when you first start it up, it will hunt around for the idle with about 300 rpm surging and Ill have to give it a little gas to stay running, this goes for about 20-30 sec.

Also when coming up to traffic lights and stuff, when I come off the gas and out of gear to brake, the car will stall out if i dont give it a little throttle. It will do this no matter how warm/cold it is.

The car also seems to be running a little too cold, the needle stays below the L in Normal on the temp gauge and sometimes even close to the 130 mark. I swaped out the stock thermo for a 180 degree, new standard volume water pump, and I also have a 2 core FRPP radiator. May this be causing it to run rich?

Lastly, when I rev the motor from idle it will choke once really quick sometimes then rev.

Timing is at 14*, fuel pressure @ 40psi vac off/30psi on

A/C + Smog deleted, no check engine light, 100k miles

Im running the TFS kit with stock injectors/MAF/throttle body.

Thanks for the help.

 

[Grn92LX]

You can try disconnecting the battery over night to erase the KAM.

May be time to invest in a tuning device if you want to do it right. Or you can try one of the Ford idle control plates that go in b/w the tb and the iac.

Also try pulling the iac harness and raising the idle to around 900-1000, maybe it will stay steady. Put the harness back in after you set the idle.

 

[Aliate X]

Well the problem Im really trying to fix is the rich problem as its costing me a lot of money.

 

[1990Coupe]

Did you ever figure out the problem? im getting like 13 mpg, i have twisted wedge heads, eddie performer intake, f-303 cam (bought the car like that) and i have same problem, stalling when downshifting and coming to a light and letting off the gas, also when its cold it wont run, it idles fine, but i HAVE to let it warm up, otherwise it backfires, sometimes thru the intake. i took it to work this AM and it was backfiring a bit, even once it warmed up. could it be my TPS??

 

[1990Coupe]

I didnt want to start a new thread since there is yours which im having similar problems..

 

[Grn92LX]

Did you ever figure out the problem? im getting like 13 mpg, i have twisted wedge heads, eddie performer intake, f-303 cam (bought the car like that) and i have same problem, stalling when downshifting and coming to a light and letting off the gas, also when its cold it wont run, it idles fine, but i HAVE to let it warm up, otherwise it backfires, sometimes thru the intake. i took it to work this AM and it was backfiring a bit, even once it warmed up. could it be my TPS??

Your cold start issue is a lean problem. Very simple to fix with a tuning device. This is what happens sometimes when you rely on just a "calibrated" MAF to do the job.

You can try disconnecting the battery overnight to fully clear the KAM (keep alive memory) and clean out the IAC valve and clean the maf elements.

 

[1990Coupe]

Your cold start issue is a lean problem. Very simple to fix with a tuning device. This is what happens sometimes when you rely on just a "calibrated" MAF to do the job.

You can try disconnecting the battery overnight to fully clear the KAM (keep alive memory) and clean out the IAC valve and clean the maf elements.

ok ill try to clean that stuff out, do you think i should have it tuned? the guy who i bought the car from put some wayyy overkill injectors in, with my HCI i have 30lbs injectors? could that be it?

 

[millhouse]

ok ill try to clean that stuff out, do you think i should have it tuned? the guy who i bought the car from put some wayyy overkill injectors in, with my HCI i have 30lbs injectors? could that be it?

The injectors should be fine….as long as they are paired up with a maf cal'd for them.

 

[poneypower89]

My car used to stall out when I pressed the clutch in... or came to a rolling stop. Turned out to be the Idle Air Controller... Go figure right? That when the car is at idle. So, clean or replace ur IAC and go from there.

 

[wht93gtEd]

My car used to stall out when I pressed the clutch in... or came to a rolling stop. Turned out to be the Idle Air Controller... Go figure right? That when the car is at idle. So, clean or replace ur IAC and go from there.

yeah man, the IAC on your car is fugly (no offense )...I say just get a new one so there's no hassle in cleaning it. It's pretty old lookin'

 

[Grn92LX]

the guy who i bought the car from put some wayyy overkill injectors in, with my HCI i have 30lbs injectors? could that be it?

30's are ideal, NOT overkill. he did it right by putting them in.

I would try what I suggested and definatly clear the KAM overnight. That might help. I wouldn't waste any money having a mild combo like that tuned, unless you are gonna use a tuning device. With a tuning device you can reuse it on any new combo you decide to build.

 

[jrichker]

Dump the codes and see what the computer says is wrong… Codes can be present without setting the Check Engine Light.

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html

IF your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Walmart.

Or for a nicer scanner see http://www.midwayautosupply.com/detailedproductdescription.asp?3829 – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $35.

 

[1990Coupe]

Thanks to everyone that replied -

grnlx - you dont think 30's are overkill? i thought 24's would be ideal? im guessing that in the future if i wanted to go FI i could survive on the 30's for a while.. I did have a check engine for the map sensor - turns out it was a BAP installed in place of a MAP, so i fixed that and the check engine went away - althought it was throwing an EGR code, all is disconnected tho.. so the KAM was reset last month 2wice..

Millhouse - the injectors are fine with the MAF, the unit on there is an old PRO M and its calibrated for the 30's

Do you guys think a dirty or malfunctioning IAC could be causing this? even tho it starts up and idles beautiful, just when i got to drive it and its cold (even on the 100 degree days we've been having) its a dog and backfires and doesnt wanna move? it wont stall if i just press in the clutch and come to a stop, it will stall if i downshift as i slow, almost like it will surge the idle and instead if surging to 450rpm's then back up, it will just die... vac leak maybe?? still that wouldnt cause the backfires when cold.

 

[1990Coupe]

I havent checked the timing think that could be causing some problems?

 

[millhouse]

I'd start off by cleaning the "old" pro-m. If it's dirty it can greatly effect off idle performance.

 

[rigamaroles]

Yeah, I'd get the timing checked.

 

[1990Coupe]

is there a special way to clean the MAF? i dont want to damage it!

 

[jrichker]

See the MAF cleaning instructions in the following code test path.

Code 66 MAF below minimum test voltage.
Insufficient or no voltage from MAF. Dirty MAF element, bad MAF, bad MAF wiring, missing power to MAF. Check for missing +12 volts on this circuit. Check the two links for a wiring diagram to help you find the red wire for computer power relay switched +12 volts. Check for 12 volts between the red and black wires on the MAF heater (usually pins A & B). while the connector is plugged into the MAF. This may require the use of a couple of safety pins to probe the MAF connector from the back side of it.

There are three parts in a MAF: the heater, the sensor element and the amplifier. The heater heats the MAF sensor element causing the resistance to increase. The amplifier buffers the MAF output signal and has a resistor that is laser trimmed to provide an output range compatible with the computer's load tables.

The MAF element is secured by 2 screws & has 1 wiring connector. To clean the element, remove it from the MAF housing and spray it down with electronic parts cleaner or non-inflammable brake parts cleaner (same stuff in a bigger can and cheaper too).

The MAF output varies with RPM which causes the airflow to increase or decease. The increase of air across the MAF sensor element causes it to cool, allowing more voltage to pass and telling the computer to increase the fuel flow. A decrease in airflow causes the MAF sensor element to get warmer, decreasing the voltage and reducing the fuel flow. Measure the MAF output at pins C & D on the MAF connector (dark blue/orange and tan/light blue) or at pins 50 & 9 on the computer.

At idle = approximately .6 volt
20 MPH = approximately 1.10 volt
40 MPH = approximately 1.70 volt
60 MPH = approximately 2.10 volt

Check the resistance of the MAF signal wiring. Pin D on the MAF and pin 50 on the computer (dark blue/orange wire) should be less than 2 ohms. Pin C on the MAF and pin 9 on the computer (tan/light blue wire) should be less than 2 ohms.

There should be a minimum of 10K ohms between either pin C or D on the MAF and ground.

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host)

http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif

 

[5spd GT]

30's are overkill. They are not needed. If you don't run with Grn92lx has, then he thinks you are wrong

24's would be more ideal.

I have 30's on my car, it is "overkill", they are not needed. 24's would be more ideal. I had actually read of a case where a user installed 24's and he said his car ran smoother and was quicker at the track compared to his 30's. A more lean powerband.

 

[88Stang331]

Might want to check the timing/compression/ and check to make sure all cylinders are firing.