FI 460... hard starts when hot... ?

NotMatt · Dec 4, 2007

This is one of those minor annoyance bugs that I'm still working out of this F-350. Specs: Fuel Injected 460, 90 F-350, E4OD.

When it's cold it starts with no trouble at all, but after I've driven it for a while and warmed it up to operating temp, it's very temperamental when starting... I have to crank it and crank it to get it to fire... and when it finally does it reeks of fuel out the exhaust... so I'm guessing it's a spark issue.

Things I've done so far (not necessarily to remedy this problem, but it might be helpful so they don't get suggested again). All new plugs, wires, cap, rotor. Fuel pressure tests out to factory specs on both pumps (40 something at idle). Timing is within factory specs. After searching, I read lots of "hard hot start" issues related to the starter cranking really slow, but that's not the issue here... it cranks fine, just won't fire easily when it's hot...

Ignition module? Coil? Anybody got any thoughts or seen this before?

Totalled · Dec 4, 2007

TFI. (igntion module on dizzy) Keep a spare in the glove box. Slather the new one with plenty of dielectric grease.

NotMatt · Dec 4, 2007

Totalled said:
TFI. (igntion module on dizzy) Keep a spare in the glove box. Slather the new one with plenty of dielectric grease.

Good info... looks like they're relatively cheap too, so I'll go buy one to swap in and keep the old one as a spare. Maybe it will make my fuel mileage better... or probably not... :haha:

NotMatt · Dec 5, 2007

Alright, so I picked up a new TFI module tonight from NAPA, but it has three extra pins on the side of it, whereas the one that's on the truck doesn't. The three extra pins are in the way of mounting it on the heatsink. The guy at NAPA says this is the part # that shows for this truck, and he doesn't have any other TFI modules without the pins...

What's the deal? What are the pins for? I plugged it in and started it for a second without the heatsink, and it runs fine... I didn't drive it since I don't want to fry the new TFI module by not having it attached to the heatsink. Can I just remove the pins and use this module, or do I need to head to a different parts store?

Totalled · Dec 5, 2007

3 extra pins? you mean like wireing pins or locating pins? Was it on the dist or was it on the fender well? There are 2 listings for 1990 460.

NotMatt · Dec 5, 2007

Totalled said:
3 extra pins? you mean like wireing pins or locating pins? Was it on the dist or was it on the fender well? There are 2 listings for 1990 460.

Fender well on a heat sink...

After researching it, it looks like the 3 pins on the side are redundant... some early rigs had the TFI module on the dist, and the three pins plugged directly into the hall effect sensor. Later models had it on the dist still, but the wiring from the hall effect sensor looped around to the regular plug. So it appears these pins are just secondary hookups for the "PIP" signal, according to the wiring diagrams I've seen online?

The 1st pic is what the one on the truck looks like... the 2nd pic is what the parts place gave me... so it appears I can just clip those pins off so it will fit in the heatsink, as I wouldn't have the hall effect sensor plugged directly in anyway with the module mounted on the fender.

Bodaciouscj7 · Dec 5, 2007

Napa does sell the correct one with out the pins on the side. I dealt with the same thing at the shop a few weeks ago. There are internal differences between the different TFI modules just as there are with the old Duraspark modules. They should be able to cross reference the engineering # of your factory part to come up with the correct one.