Truck runs fine then misfires and over heats.

I have a 1984 ford pickup with the 5.0 EFI in it. it will start up and run fine then after a while its like the timing changes it starts to buc and miss i hear my lifters rattling and my tach meter jumps all over the place (not with the engines real RPMs it just bounces every were). It starts to over heat i smell burnt oil. Kinda seems like it desles when its running. I changed the coil cap and roater. I dont think its the Ignition control module because there either good or bad not kinda bad or going bad if it was bad it wouldnt start. Then when it dies and i try to start it again it cranks over hard like its way out of time the only thing that controls the timing is the ICM. Also it dosnt do it all the time. It will go away then come back.

Reply to
cittra3333
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  1. No... the TFI is NOT always 'good or bad'

  1. You seem to understand a fair amount about the TFI, so here's a thought:

- what is the physical indication that a TFI is likely to be going bad?

Bottom line, you're probably going to pull that TFI off there and find you've let a perfectly good TFI go bad by not keeping the lube fresh every five years or so.

It COULD also be the ignition pickup.

Reply to
Backyard Mechanic

"" wrote: > cittra3333 wrote: > > > I have a 1984 ford pickup with the 5.0 EFI in it. it will > start up and > > run fine then after a while its like the timing changes it > starts to > > buc and miss i hear my lifters rattling and my tach meter > jumps all > > over the place (not with the engines real RPMs it just > bounces every > > were). > > It starts to over heat i smell burnt oil. Kinda seems like > it desles > > when its running. I changed the coil cap and roater. I dont > think its > > the Ignition control module because there either good or bad > not kinda > > bad or going bad if it was bad it wouldnt start. Then when > it dies and > > i try to start it again it cranks over hard like its way out > of time > > the only thing that controls the timing is the ICM. Also it > dosnt do > > it all the time. It will go away then come back. > > > > 1. No... the TFI is NOT always 'good or bad' > > 2. You seem to understand a fair amount about the TFI, so > here's a > thought: > > - what is the physical indication that a TFI is likely to be > going bad? > > Bottom line, you're probably going to pull that TFI off there > and find > you've let a perfectly good TFI go bad by not keeping the lube > fresh > every five years or so. > > It COULD also be the ignition pickup. > -- > Yeh, I'm a Krusty old Geezer, putting up with my 'smartass' is > the price > you pay..DEAL with it!

The TFI was replaced about a year ago when it went out i had no spark. But im going to take it off and put another on it to make sure also Were is the ignition pick up and could that cause it to freak out then run fine the truck will bump over if you shut it off and try to start it up right after it starts having its problems. The TFI is the only thing that controls the Tach and the Timing isnt it :?: Thank you

Reply to
cittra3333

pickup is inside the distributor. it may be bad and could cause those symptoms.

And yes the TFI COULD be bad .. esp if there's no brand on it and you bought it at a discount AP store.

Reply to
Backyard Mechanic

as a side note.... did ford have efi in 1984 f 150 5.0l? in canada it was 1986 for first year of efi in ford pickups

Reply to
fireater

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