One Last Problem and she's ready

[MTLBLKNOTCH]

Ok since my last post in the last few months I have changed the complete harness in my 88 LX to one from an 89 with the A9L computer. This worked great as the car starts great now but I have come to find one problem. I was not able to start the car after it was running for a few mins, I then did an ohm check on the curcuits and then a short to ground test which had me find the nuatral switch was shorting to ground. I unplugged it from the top of the tranny and the car starts every time no problem. Now what I have found is when I start the car the rpm's are at 2500 then when I release the clutch it drops to 1100 rpm and settles at 800, but if I press the clutch in and release it the car stalls?? This is the problem I am facing now.

I have heard a few different ways this can be fixed, 1)ground the black/white wire on ther clutch switch. 2)flip the black/white with the blue wire beside it.

and I have also heard something about a pin swap at the plug for the dash harness where it plugs into the computer harness.

Can anyone help me with this problem please?? I have come so far with this project and this is really the last thing in my way from finishing. After this is finshed I will begin the reassembly of the car from the inside out.

Thanks:SNSign:

Sean

 

[jrichker]

It sound more like idle problems than wiring. See "Help me create the Surging Idle Checklist" at http://forums.stangnet.com/showthread.php?t=534062
for help with your idle problems. The first post contains all the updates to the fixes. I continue to update it as more people post fixes or ask questions.

 

[MTLBLKNOTCH]

No no the car starts every try, but when it does the rpm's are over 2500 and when I let go of the clutch the rpm's will drop to about 1100 and once the car is wormed up they are at about 800rpm. The problem is when I touch the clutch after the car is running and let it go again the car then dies? it just goes off.

Sean

 

[MTLBLKNOTCH]

It sound more like idle problems than wiring. See "Help me create the Surging Idle Checklist" at http://forums.stangnet.com/showthread.php?t=534062
for help with your idle problems. The first post contains all the updates to the fixes. I continue to update it as more people post fixes or ask questions.

No no the car starts on every try, the problem is that when I start the car the rpm's are very high and after they settle down if I press the clutch and release the car dies.

 

[jrichker]

The black/white wire is signal ground for the computer. Do not ground it to anything, since it may pick up electrical noise that can affect sensor operation.

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/detailedproductdescription.asp?3829 – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $35.

Wal-Mart may now have the LCD display scanner for less than $35

 

[MTLBLKNOTCH]

I have both the last scanner you posted and the Ford Rotunda scanner from the dealer.

I have yet to scan for codes as before I found the short to ground in the nuatral switch I was not able to scan the car.

 

[MTLBLKNOTCH]

No other ideas from anyone? I will be checking the readings of the TPS key on engine off tomorrow to see what happens with the voltage as I press the clutch.

Sean

 

[MTLBLKNOTCH]

So I am geussing this isi not a comin problem when people do mass air conversions.