New here,got a question.

[MidLife98Crisis]

Hey guys,just joined mainly to see if anyone has had the same problems I have and if there are any simple solutions.I just finished over the holiday weekend putting a set of ported and polished P.I. heads and a ported and polished Eldebrock Torker II intake with the 1406 Eldebrock Performer carb on the 98 Mustang I inherated from my daughter.I have the MSD Mod6 ignition module to fire things off.A set of Trick Flo valve covers looks good also.Also put a 3 row Aluminum radiator in it for good measure with a 170 degree thermostat,also a set of BBK shorty headers and 2 1/2 inch exhaust into 40 Flowmasters with a X pipe in between.I had to step down fuel pressure into the carb so I went with a Summit fuel regulator with a return to get the job done.Also added a 40 amp relay to turn on pump anytime ignition is on.Sounds great ,runs like a scalded dog,but and here it is,the question. Nothing from the computer will work, I get no fuel pump signal(dont need it ,but I checked) the AC wont come on ,the electric fan on radiator wont come on.So what tells the computer the engine is running? there must be an input to the brain that tells it its running.Anyone got any ideas?I could power all of that externally with relays,and if I have to, I will but anyone done this before and figured it out?Thanks in advance.
Tom
sorry so long winded.

 

[wmburns]

The PCM uses the CKP signal to tell if the motor is running. The CKP signal drives the tach.

All of the devices can be "fooled" to work by providing the signal that the device is expecting. Most are ground start. The low speed fan is a +12 volt sense.

I can help with wiring diagrams. Much too many and too large to post. PM if interested in acquiring a set.

 

[MidLife98Crisis]

Thanks,that would help.CKP signal ?I have wiring diagrams,where does that signal come from?

 

[wmburns]

CKP=crank shaft possition sensor. The thing on the front crank shaft that reads the teeth on the reluctor wheel.

 

[MidLife98Crisis]

Duh

Duh!!! guess I had a brain fart,Thanks,still that would have to be a pulsed signal for the engine running,wouldnt it? I wonder if I could get that signal from the MSD Mod 6 module? ILL try asking the guys at MSD.

 

[wmburns]

I guess I don't understand fully what you are trying to do. Yes I know you want to "fool" the stock PCM into thinking that the motor is running. But to what end?

To get the engine cooling fans to work will also require input from the engine coolant sensor. The PCM will also need the transmission VSS speed sensor.

Note, without an engine temperature sensor the fans will run all of the time.

The AC should work assuming that the other AC sensors are still in working order.

The fuel pump will also need the fuel pressure sensor input.

THEN... you need to think about something called "failue mode effects management". This is what the PCM does in response to certain failures. For example, if the PCM "thinks" the motor is running hot, it will disable the AC clutch. I'm telling you this so that it won't be a complete surprise if after providing a CKP signal, that the PCM starts doing other strange things because of missing sensor inputs.

Good luck.

 

[MidLife98Crisis]

Thanks for your interest and help,I will try to explain.I want the car to work( radiator fan running when it is suppost to,AC comes on when I turn it on,things like that) like it did before I did away with the fuel injection,egr,oxygen sensors and all the other smog,pollution,bull****.Right now I have a carb sitting on an intake,feeding into the engine and a MSD ignition box firing the plugs.I can vary the timing ,advance,etc with a program loaded into my laptop.Its basically Old School as am I,I love the sound when the back 2 barrels kick in on a 4 barrel.It was something I read about in Hot Rod and having a Mustang sitting around I decided to try it.I can do it all with seperate relays for everything,as I already have with the fuel pump(it comes on thru a relay I added when the ignition is turned on),I just was wondering if anyone had allready done this,and had any tips or secrets about getting everything to work on the car like it did before I did the conversion.I can do without the AC,can get an aftermarket tach for rpms,just wanted to keep the fan setup for the radiator .It still runs thru the temp sensor and sends a signal back to the ECM but wont send a signal to the fan to come on,and since the ac wont come on(even with pressure switch jumped) the high speed fan wont come on either.I can do it all externally with separate relays,and I guess I will have to,I just wanted to know if anyone had worked it out before with the stock ECM.