Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: Soul on June 18, 2012, 03:58:15 PM

Title: Bad TFI? Or something killing it?
Post by: Soul on June 18, 2012, 03:58:15 PM
Ok so I have my car below in the sig, the mass flo is pretty much a 87-93 mustang setup with a diff intake. The car was acting wierd till I swapped the TFI then ran great, took it down the road and it just died while running, pulled over and had no spark (didn't check for power at the coil at the time). Went and swapped TFI again and still no spark. Went home to get dolley to load it and then it started np and ran fine. Ran out of time to mess with it but no codes are being thrown. Any suggestions on stuff to check? Will be a week or two before I get a chance to mess with it and want to stock up on ideas.

Also the TFI was not hot to the touch when it died, the wiring harness is all brand new so the connectors look good.
Title: Bad TFI? Or something killing it?
Post by: Soul on June 18, 2012, 03:59:40 PM
Will try a TFI relocation but I don't think it is getting hot. And will check the PIP strator.

Also last time this happened with no start, the coil did have power.
Title: Bad TFI? Or something killing it?
Post by: dw85745 on June 18, 2012, 04:29:07 PM
Soul -  Sound like your running into same issue as myself (see post Finally - NO Start).

Something you might want to start with is this test to eliminate faulty ignition switch and neutral safety switch.

Quote
Actually neutral safety switch not a bad guess -- is part of the start-crank circuit -- but since engine cranks, IMO this drops it out of the picture.
Easy test for this (and the ignition switch) is to run the common DVOM lead to the dissy base and then turn the iginition switch to both run and start while separately checking TFI pins 2, 3, and 4 (use straight pin attached to pos DVOM lead).
If you get 90% of battery voltage both ignition and neutral safety switch are OK.

Re: Relocating TFI - I wouldn't bother - especially if a newer TFI module.
Ford finally found the heat issue with them which was an air bubble during the manufacturing process.
Once this was eliminated (air bubble) -- took number years to find that's why Ford relocated it several times -- the "TFI" problem went away.
That's not to say you could have a bad TFI, but I doubt it.
Title: Bad TFI? Or something killing it?
Post by: Soul on June 18, 2012, 05:22:56 PM
Thanks for the feed back, don't think it is my N safety switch But it could be. The ignition switch was just changed due to a dash fire from it lol.
Title: Bad TFI? Or something killing it?
Post by: FirstBird on June 18, 2012, 05:47:35 PM
I know this might be stupid but check your battery, my battery is a bit smaller than
The tray and i guess it would move around causing it to die randomly but would start back up after a bit.
Title: Bad TFI? Or something killing it?
Post by: Soul on September 06, 2012, 11:18:08 AM
Ok updating this just so if someone else is in this hell they have something else to try. Ended up being the pickup in the dist. Even though it was brand new, it had gone bad and fried the TFI also.
Title: Bad TFI? Or something killing it?
Post by: TOM Renzo on September 06, 2012, 08:21:01 PM
One of the biggest enemies of the TFI module is the state of tune the engine is in. If your tune is messed up the TFI will fry faster than you can SPIT. Always keep your TFI equipped cars in perfect tune or you will find out just how fast the unit will GO SOUTH!!!

NOTE!!! If your NSS is shot the engine wont CRANK!!!!