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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

New computer Or reprogram??

  • Thread starter Thread starter Chietala
  • Start date Start date Dec 21, 2006

Chietala

New Member
Sep 21, 2006
111
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0
Sacramento
Dec 21, 2006
#1
  • Dec 21, 2006
  • #1
I'm right in the middle of rebulding the 5.0. I need to find a place that I can send my comp. to for reprograming. The car ran rich before and If it does on start up and breakin then I'll wash the rings out.

Buy new comp. or reprogram?
 

vristang

15 Year Member
Mar 31, 2005
4,933
101
124
Seattle
Dec 22, 2006
#2
  • Dec 22, 2006
  • #2
Chietala said:
I'm right in the middle of rebulding the 5.0. I need to find a place that I can send my comp. to for reprograming. The car ran rich before and If it does on start up and breakin then I'll wash the rings out.

Buy new comp. or reprogram?
Click to expand...

Your situation is a little tricky.
However, you will not want to send the computer to some random shop for a 'custom' tune. All they will do is guess at what needs to be changed, and you will still have no guarantees regarding startup.
Even with a mail order chip, the situation would be the same.

Normally, I would suggest fixing the rich issue before pulling the motor, but since the car is not currently running, you can't pull the codes or do other diagnosis work.


The best alternative I can think of is for you to list ALL modifications you have made to the car, especially
computer (A9L, A9P, X3Z, etc)?
MAF / MAS combo?
Injector size?
Any other info that may help?

Did the rich condition start with a hardware/parts change?

jason
 

Chietala

New Member
Sep 21, 2006
111
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0
Sacramento
Dec 22, 2006
#3
  • Dec 22, 2006
  • #3
hmmm good question. I'm not certain because I bought the car with most of the upgrades installed. I also based this assumtion on the drivability, and smell of the car. I never did any test or dumped codes. It's hard to tell with an off road x-pipe also.

I can tell you that every part of that motor and back of the x-pipe had un-spent gas in it. I'm just going on experiance on this one.

What about a brand new factory computer? The only thing I'm worried about is washing the rings. I'll have it dyno tuned after a few hundred miles.

A friend and I just had this problem with his Lt1. Pulled the damn thing twice because his adjustable fuel fressure regulater was set to high. The rings never set.
 

jrichker

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#4
  • Dec 22, 2006
  • #4
The stock computer will work well with your combination and far beyond what you currently have. It is adaptive and will make adjustments for most modifications except NO2 or pressurized induction.

The combination of a H pipe without cats and some bad O2 sensors will make a smelly car. Without dumping the codes, you have no idea what sensor or system is malfunctioning.

If you are going to keep the car, plan on learning about what makes it run and how to work on it. Paying someone else to do the work will make you poor and frustrated. A Helm or Chilton's shop manual will be your friend. An investment in tools and some books will be a must have.

Here's a book that will get you started with how the Ford electronic engine control or "computer" works.

Ford Fuel Injection & Electronic Engine Control 1988-1993 by Charles Probst :ISBN 0-8376-0301-3.

It's about $20 from Borders.com see http://www.amazon.com/ . Select boo...ttp://www.veryuseful.com/mustang/tech/engine/

Brakes and 5 lug conversions are Matt90GT’s specialty
http://www.svo73mm.cjb.net/

Wiring diagrams for your car: AutoZone has them -
http://www.autozone.com/servlet/UiB..._us/0900823d/80/19/59/5a/0900823d8019595a.jsp

Electric fan and alternator upgrade (can’t do the fan without a bigger alt)
http://www.geocities.com/smithmonte/Auto/

To make sure your second hand rose doesn't turn into a sticky cactus, you need to some investigation. Check to see that all the sensors are connected. MAF, MAS, TPS, ECT, ACT, O2, VSS & EGR all need to be plugged in. The fuel pressure needs to be set at 37-39 PSI. The stock fuel pressure regulator isn't adjustable, so if it is out of spec, replace it with an adjustable one. AutoZone or other auto parts store will rent/loan a fuel pressure test gauge.

Here's how to dump the codes and see what the computer says is wrong…Codes may be present in the computer even if the Check Engine light isn’t on.

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 Wal-Mart.

Or for a nicer scanner see http://www.midwayautosupply.com/pc-7208-90-equus-digital-ford-code-reader-3145.aspx – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $35.
 

vristang

15 Year Member
Mar 31, 2005
4,933
101
124
Seattle
Dec 22, 2006
#5
  • Dec 22, 2006
  • #5
Chietala said:
hmmm good question. I'm not certain because I bought the car with most of the upgrades installed. I also based this assumtion on the drivability, and smell of the car. I never did any test or dumped codes. It's hard to tell with an off road x-pipe also.

I can tell you that every part of that motor and back of the x-pipe had un-spent gas in it. I'm just going on experiance on this one.

What about a brand new factory computer? The only thing I'm worried about is washing the rings. I'll have it dyno tuned after a few hundred miles.

A friend and I just had this problem with his Lt1. Pulled the damn thing twice because his adjustable fuel fressure regulater was set to high. The rings never set.
Click to expand...

The above post from JR has some good general advice.

There are 2 main ways you can end up running poorly.
1. Defective parts.
2. Mismatched parts.

There is littl you can do to check for defective parts now.
But you can go through and make sure all components are appropriate.
I would start by pulling the computer from your passenger kickpanel. There will be a 'catch code' on a sticker on the computer. It will probably be A9L or A9P, but there are other possibilities.

Then take a look at the MAF/MAS. If the housing is a Ford unit, then check the Inner diameter of the tube. It will be 55mm if it is a stock Fox MAF. Also, the stock Fox sensor (MAS) should be an 'F1ZF' (this number will be branded into the top of the sensor).
It is possible that an sn95 MAF (70mm) was used on the conversion. If this is the case then look for the part number on the MAS. I think it would be F1SF?

If the MAF housing is an aftermarket unit, then try to determince which company produced it. This should be cast into the housing (C&L), or marked on the sensor (PMAS). Many aftermarket companies will even state the calibration on the meter itself.

Also, let us know what size your injectors are. Orange injectors are 19Lb, Blue are 24Lb, etc.

Hopefully, you will find that the rich problem was caused by a mismatched MAF/Injector. Then you can correct the issue, and break in the motor safely.


Good luck
jason
 

Chietala

New Member
Sep 21, 2006
111
0
0
Sacramento
Dec 22, 2006
#6
  • Dec 22, 2006
  • #6
Well thanks for answer on the computer question jrichker.

For the other advice, I am keeping the car and I'm well aware of how to rebuild the 302 pushrod motor. I can double check but I don't think the manual tells you the answer to the question I had. But no doubt I thank you sincerly for the advice!
 

Chietala

New Member
Sep 21, 2006
111
0
0
Sacramento
Dec 22, 2006
#7
  • Dec 22, 2006
  • #7
vristang said:
The above post from JR has some good general advice.

There are 2 main ways you can end up running poorly.
1. Defective parts.
2. Mismatched parts.

There is littl you can do to check for defective parts now.
But you can go through and make sure all components are appropriate.
I would start by pulling the computer from your passenger kickpanel. There will be a 'catch code' on a sticker on the computer. It will probably be A9L or A9P, but there are other possibilities.

Then take a look at the MAF/MAS. If the housing is a Ford unit, then check the Inner diameter of the tube. It will be 55mm if it is a stock Fox MAF. Also, the stock Fox sensor (MAS) should be an 'F1ZF' (this number will be branded into the top of the sensor).
It is possible that an sn95 MAF (70mm) was used on the conversion. If this is the case then look for the part number on the MAS. I think it would be F1SF?

If the MAF housing is an aftermarket unit, then try to determince which company produced it. This should be cast into the housing (C&L), or marked on the sensor (PMAS). Many aftermarket companies will even state the calibration on the meter itself.

Also, let us know what size your injectors are. Orange injectors are 19Lb, Blue are 24Lb, etc.

Hopefully, you will find that the rich problem was caused by a mismatched MAF/Injector. Then you can correct the issue, and break in the motor safely.


Good luck
jason
Click to expand...

There 19lber's.
MAF is stock.

I'll just get my self an A/F and Fuel pressure gauge for start up.

Thanks for the help!
 
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