Trouble with my 5.0L stalling

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5.0L having trouble "staying lit" when hot

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I dropped a SEFI, 5.0L from an '86 Lincoln MkVII into my '53 Mercury M1oo.

It starts no problem ... however, once it's warmed up she's takiin to stalling... particular in intersections and when my 12 year old daughter is on board! [Too much xx]

I've replaced the TFI twice! , and found a poor conncetion as well
and repaired them but the truck is still stalling out when I, come to a stop...not consistently, just annoyingly frequent!

I've been camping with the family the past 4 days in the Muskokas.

I was dissappointed I couldn't take the truck but it just isn't dependable enough yet for family travel

ANyways, I'm going ou to the garage later tonight or tomorrow and wondered if any of you gearheads had any other suggestions or a protocol for tracking down this nasty varmit of a problem

LMK

GW

Any suggestions?

 

I put an 86 5.0L in my '69 F-100. It was from a towncar so I'm assuming we have the same motor (SEFI and speed density). If you know how to pull the codes that is a definite start point. I fixed a similar problem by getting a new throttle body air bypass valve (not sure if thats the real name of it... it sits at an angle at the side of the throttle body above the throttle cable and has a two wire connection). Obviously all the vacuum lines need to be checked. The SEFI temperature sensor sounds suspect, it's located in the intake manifold to the LEFT of the distributor. (The one on the right goes to the temp gauge). Another thing, did you mount your MAP sensor away from the engine? They don't like heat or a lot of vibration.
If all else fails just go ahead and replace the O2 sensors (you should have two) then try running for short distances (at operatiing temp) with one of the sensors electronically disconnected (MAP, temp, throttle position, canister purge, EGR, and air injection relays). I did this and found a bad connection on the temp sensor... if you pick the errant sensor you should notice little change in performance... if you pick an operable sensor... the engine will be noticeably off. The EEC IV has several "modes" such as Cold Start, Hot Start, No Start, normal cruise, etc... It also has a "get me home " mode that will keep the car running if ALL the sensors are out of whack.
I've tried all these... I don't claim any expert status, so please excuse any technical errors. I have been running my '69 with the 5.0L for 3 years and am mostly satisfied with it.
By the way, mine is non-HO but has the HO firing order... does yours?

Good Luck
CT