hey everybody! this is my first post but surely not my last. i love f-bodies and i also love to tinker with cars in general! i have a 1987 Formula WS6 with the venerable TPI 305 and the Borg-Warner T5 manual. yesterday i did the fan modification. i originally tried to wire both fans to a switch but the switch immediately blew, so i wired both fans together and put them on the 20 amp c/h fan fuse. i know i didnt do this mod properly and i am going to put a switch in today. my problem is this: the car runs cool as cool can be now, gets up to 220 if you dog it, but about 3/4 of the way through a 20-30 mile trip the service engine soon light will come on and the car will usually stall. i get a code 12, i looked it up as "no TACH signal to ECM". but late last night as well as this morning the light hasnt came on at all! the car just dosent feel as powerful though. i tried to powerbrake (something i dont do frequently) and i got embarassed. the brakes wouldnt hold and the car wouldnt powerbrake at all. i love this car and wont sell it for anything but im new to this TPI thing (though friends have had TPI'd cars for years) so if someone could help me id greatly appreciate it. if i did the mod wrong could someone point me in the right direction to do it right? my other question to my fellow f-body fans is, what intake seems to work best on my car, you know, most power, torque, so forth? me and my buddy were changing out my thermostat when we were reminded what happens when you put steel bolts in an aluminum manifold. now my thermo housing (complete with new 180 degree thermo!) is held on with one bolt and one mini c-clamp. and lots of rtv. i also have had a problem, before breaking the bolt off, with my baby running hotter and hotter at higher speeds, could this be due to the air dams being off the car? i just got the car and am still getting to know it. thanks for taking the time to read my "book"!

1987 Pontiac Firebird Formula
Primer front, blue rear, soon to be back in Black!
WS6 suspension, 245 50ZR-16 pirelli tires, handles awesome!
TPI 305 rated at 205 hp, we'll have to fix that!
T5 manual tranny with high performance Hayes clutch
beautiful in my eyes, soon to be beautiful to rest of world
"A Mustang a day keeps the junkyard away!":rockon:

 

Get the air dam!! Mine fell off and the car ran over 220 degrees onthe highway. when i got a new one it went back down to 160. Also code 12 is the diagonstic function of the ecm, it is telling you that it is working properly. Are you usng the paperclip method if getting codes?? if so the computer will blink code 12 for three times and it then will go on to blink other codes, if any. Hope this helps

 

Welcome to thirdgen.org.

I'm not exactly sure what you've done, but what you want to do is control the fan relays, not the fans themselves.

I believe there's a Tech Article you'll find from the main page, look it over..something like "total fan control".

 

thanks for the advice but i still have some unanswered questions. first off, if 12 is the diagnostic code, then why does the light come on while driving and my car stall out? im not arguing, i am just curious. and, by the way, yes i am using the "paperclip method" to retrieve codes. and, heres an update to my previous post, i installed a switch for my fan, left it off (had the original harness hooked up too, wanted to see if car could control its own fan) but when it got time for the car to turn the far on i saw a lot of smoke and turns out i smoked my orange lead wire, oopsie daisy! if you could help id be greatly appreciative. also, i know those valves a supposed to be self-adjusting, but what should i do if im using nothing but 92-octane and under acceleration to about 2500-3000 rpms i hear them? shoud i try to find 112 octane or is there a way to adjust these? also, one last question, my throttle position sensor is acting up (car wants to idle at 2k when coming to a stop light), would that make the car act like its acting? thanks

1987 Pontiac Firebird Formula
TPI 305, T5 manual, WS6, my favorite abbreviations
"A Mustang a day keeps the junkyard away!":rockon:

 

Coide 12 is as you described...no refernce pulse to ECM...means things are working because thew engine isn't running So all's cool.

About the "valves"...I think what you're hearing in detonation..knock...ping...not the valves.

About the fan control, read my previous post, don't try to control the fans...control the fan relays.
The relay's hold the current...generally need a much smaller current to control.

IIRC, each one of my fans have a 30 amp fuse..be awful tough to control BOTH of them directly as you've described above, without smoking the fuse/wiring/fuse you're running.

Suggest you put the car back to the way it was originally, then modify it correctly by controlling the fan relay's on/off with a switch.

 

Oh boy...

 

so the only unanswered questions i have are as follows: first, why is my Formula's service engine soon light coming on during travel if all is well? could this have anything to do with a malfunctioning throttle position sensor? the light hasnt came on in the last 2-3 trips, so im kinda baffled. what about the car stalling? could these problems all be the tp sensor? thank you so much for answering these questions ive encountered in getting an awesome 'Bird back flyin' high again!

 

You might try reseting the computer (disconnect the negative batter cable for about 10 mins, I beleive). If/when it trips the SES light, try reading the codes again. If you all you get is code 12, it might be the computer. The TPS code is 21 so make sure you watch it carefully.

 

if you put your car in the "on" position but don't start it your ses light lights up correct? its telling you that your car isn't started but the key is there in the "on" position. it doesn't give a code or anything. thats what it is telling you. your car is just dying randomly and the ses light comes on to say "the key is in on position but the engine isn't running" and doesn't give a code.
i would look at your pcv valve because if it isn't clean your car can stall. it happens to my dads jimmy. also vaccume leaks can make it stall (getting air by the maf without going through it throws the car off)
if you still have trouble just ask again.
Andrew