Hey Gang,
I have been chasing an ignition problem for quite some time now, and I'd like to share my experience buying new TFI modules as a cautionary tale for those who may be in the market for one.
I had my original module tested at Autozone, and it passed. For gits and shiggles, I also did some "rough" resistance tests on it too, which confirmed Autozone passing result. (Note that "rough" resistance tests were only to make sure that there was resistance on pins that should have ohms and no resistance on pins that should have 0 ohms. These are the only meaningful resistance tests to be performed when bench testing the module itself--the ohm values aren't so important--it's GO/NO-GO. Same idea as when checking resistance on capacitors that are wired into a circuit board; only infinite or 0 resistance results are meaningful.)
See:
http://www.myo-p.com/Ford-EEC/EEC Help files/Files/TFI test and troubleshooting.html
for a diagram showing which pins should have SOME resistance an which should have none.
Anyway, my original unit tested fine both ways, but i ordered another one so as to have a spare on hand as i understand that our cars are notorious for burning through these things. Here's where the debacle begins..
1. Ordered OE replacement unit from LMR and bench tested it straight out of the box. Sure enough, the GO/NO-GO resistances were all jacked up. It was clear that one particular pin had an internal break. It had OL ohms across the board. Took to Autozone: fail confirmed. Called LMR and was able to convince the guy that it was DOA and to give me a refund w/o being on the hook for return shipping, although, it did take some doin'. He surely would not have been so "understanding" had i installed the unit--he asked about this twice. Guy also asked if i got receipt from Autozone confirming fail (Note: Autozone provides no such receipt and clerk will look at you funny for asking). I am grateful to have received refund.
2. Ordered Motorcraft unit from RockAuto. Second verse same as the first. Failed bench test and Autozone test (this time i snapped a pic of the unit failing on Autozone's machine.. My "receipt of failure" in case RockAuto asked). The refund/exchange process with RockAuto was much easier. However, i noted that my Motorcraft unit curiously had no Motorcraft/Ford logo like my old one. According to Ford Motorcraft website's FAQ,
How do I know if a part is counterfeit?
"Unfortunately, our high quality breeds a lot of imitation. Every Ford Part is stamped with the Blue Oval or Motorcraft® brand so that you know it’s authentic. If a part you received does not have one of those stamps, then it’s not a Ford Part."
I contacted Ford Motorcraft with pics and they said it was legit despite no branding and that my beef was with RockAuto seeins how they sold me a broken part. Weird, considering what their website says, but okay. Initiated RockAuto exchange, no problem.
3. Received second unbranded Motorcraft module; same outcome as before! Failed both tests. Now i will initiate a refund because i am tired of bench testing new parts and running to Autozone all the friggen time (however, i now know how to use their ignition testing equipment better than many of their associates ).
In summary, watch out. Be sure to have your new TFI modules tested prior to installing them. Vendors are inclined not to accept returns on these parts--Motorcraft units included--if they've been installed. Also, take pics of the failing test result should vendor ask for a "receipt of failure."
I have no idea what's going on with brand new TFI modules these days. I have pulled myself out of the market for the time being as my original unit--the one that SAYS Motorcraft--is still serviceable. I hope this post is not too rambling and incoherent, and i hope it proves useful to some of y'all.
I have been chasing an ignition problem for quite some time now, and I'd like to share my experience buying new TFI modules as a cautionary tale for those who may be in the market for one.
I had my original module tested at Autozone, and it passed. For gits and shiggles, I also did some "rough" resistance tests on it too, which confirmed Autozone passing result. (Note that "rough" resistance tests were only to make sure that there was resistance on pins that should have ohms and no resistance on pins that should have 0 ohms. These are the only meaningful resistance tests to be performed when bench testing the module itself--the ohm values aren't so important--it's GO/NO-GO. Same idea as when checking resistance on capacitors that are wired into a circuit board; only infinite or 0 resistance results are meaningful.)
See:
http://www.myo-p.com/Ford-EEC/EEC Help files/Files/TFI test and troubleshooting.html
for a diagram showing which pins should have SOME resistance an which should have none.
Anyway, my original unit tested fine both ways, but i ordered another one so as to have a spare on hand as i understand that our cars are notorious for burning through these things. Here's where the debacle begins..
1. Ordered OE replacement unit from LMR and bench tested it straight out of the box. Sure enough, the GO/NO-GO resistances were all jacked up. It was clear that one particular pin had an internal break. It had OL ohms across the board. Took to Autozone: fail confirmed. Called LMR and was able to convince the guy that it was DOA and to give me a refund w/o being on the hook for return shipping, although, it did take some doin'. He surely would not have been so "understanding" had i installed the unit--he asked about this twice. Guy also asked if i got receipt from Autozone confirming fail (Note: Autozone provides no such receipt and clerk will look at you funny for asking). I am grateful to have received refund.
2. Ordered Motorcraft unit from RockAuto. Second verse same as the first. Failed bench test and Autozone test (this time i snapped a pic of the unit failing on Autozone's machine.. My "receipt of failure" in case RockAuto asked). The refund/exchange process with RockAuto was much easier. However, i noted that my Motorcraft unit curiously had no Motorcraft/Ford logo like my old one. According to Ford Motorcraft website's FAQ,
How do I know if a part is counterfeit?
"Unfortunately, our high quality breeds a lot of imitation. Every Ford Part is stamped with the Blue Oval or Motorcraft® brand so that you know it’s authentic. If a part you received does not have one of those stamps, then it’s not a Ford Part."
I contacted Ford Motorcraft with pics and they said it was legit despite no branding and that my beef was with RockAuto seeins how they sold me a broken part. Weird, considering what their website says, but okay. Initiated RockAuto exchange, no problem.
3. Received second unbranded Motorcraft module; same outcome as before! Failed both tests. Now i will initiate a refund because i am tired of bench testing new parts and running to Autozone all the friggen time (however, i now know how to use their ignition testing equipment better than many of their associates ).
In summary, watch out. Be sure to have your new TFI modules tested prior to installing them. Vendors are inclined not to accept returns on these parts--Motorcraft units included--if they've been installed. Also, take pics of the failing test result should vendor ask for a "receipt of failure."
I have no idea what's going on with brand new TFI modules these days. I have pulled myself out of the market for the time being as my original unit--the one that SAYS Motorcraft--is still serviceable. I hope this post is not too rambling and incoherent, and i hope it proves useful to some of y'all.