Did it do this before you replaced the engine? It is less likely a wire than a bad connection or a bad sensor. Also make sure that it is the correct throttle body for the engine; swap out the old one if you have it and see what happens. A chugging or jerking at certain light throttle conditions usually mean a improper mixture (I think too lean is more likely). Check for codes if you haven't already; that may give you a clue (or lead you wildly astray). No-starts are easy to fix compared to not running quite right, I've found.
1984 Mercury Cougar 5.0L missing when warm
Hi all, Need some help if possible. I have a recently rebuilt engine (long block) with a new EFI (throttle body) and when cold, it sometimes 'bumps" or misses, but when warm, it more pronounced. I realize these issues may be hard to track down, wiring wise, but if anyone has any ideas, I'd be grateful. I've checked the connection going into the front of the EFI, which had a broken wire (fixed that, hoping that would do it) and it's still acting up.
Anyway, let me know of any rabbit holes to go down...
thx.
Anyway, let me know of any rabbit holes to go down...
thx.
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It actually happened before the new engine and new throttle body. The car was in Penn. amongst the salt ladened roads and the wiring harness isn't the best.
Man, that could be so many things. See if you ca get a code read and also give the best description that you can on how it runs. C
Connectors don't like salt either, could be part of it.
Connectors don't like salt either, could be part of it.
I'll ask my guy is they had any codes.... Unfortunately, I can't find a new or reman wiring harness. Summit has one that might work, but it's not exact. Also, taking out a wiring harness is way above my pay grade. Thank you!
Nah, a Summitt harness is for someone who has a lot of time and wants a completely new and different harness. Good for a simple car but hard on yours. If your harness really is bad (it's probably not though), a junkyard is the way to go. Not many people (professionals included) know how to trace down electrical/engine mild problems.
Nah, a Summitt harness is for someone who has a lot of time and wants a completely new and different harness. Good for a simple car but hard on yours. If your harness really is bad (it's probably not though), a junkyard is the way to go. Not many people (professionals included) know how to trace down electrical/engine mild problems.
Hopefully, I've found a guy who great at tracking down these issues. I had to go outside my current shop. They are a small team with only one good Mechanic and he's swamped. The two other techs are too green to know what to do. I'll keep you informed. After running it a few days, me thinks its the fuel pump/sender/connection.
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