84 Timing Issue

[Roncobbusc]

Thanks for adding me - new to group 1984 F150 XLT 351W 2bbl auto 4x4

Think I have a timing issue, but I've never messed around with electronic ignition before. Truck starts fine with good idle, but after couple minutes idle is very high, drive it for about 20 minutes and turn it off, she won't start until it cools off for about 20 mins. If I retard the timing a touch, will the ECM just walk it back up?

Thanks!

[Gary Lewis]

Welcome to the forum!  Glad you joined.  

But you may have missed the email I sent you asking you to go to the New Members Start Here folder, read the guidelines, and then make your first post an introduction there.

Not to worry, that's fairly common.  But the first reason we do that is to make sure you've had a chance to read the guidelines, which are posted there.  We hold everyone to those guidelines so it is important that you read them.  Have you?

The other reason we do that is because we are a community and want to get to know everyone.  So we like to find out a bit about you, including where you live, etc.

[Gary Lewis]

I'm guessing that your ICM isn't one of the ones with the retard function for starting, and that you have a lot of initial advance dialed in.

You said "she won't start until it cools off for about 20 mins".  But what does it do?  Spin and no fire?  Or kick back when you try to spin it?

[Roncobbusc]

It will spin but it drags - almost like trying to start with a dying battery. But once it cools off, it'll fire up.

[Gary Lewis]

It sounds like it is the starter then.  The bushings on starters wear and then the armature touches the field when the starter is hot and expands.  That causes them to slow down and to pull extra current.  That causes them to get hotter and expand more, which.....

[1986F150Six]

While hot and the starter drags, with the key off, pull the ignition coil wire and try to start. If the engine spins normally [faster], then the dragging is due to too much advance in the timing.

[85lebaront2]

Can you get a parts store or shop to measure the current draw on the hot starter? That will prove if it is the starter. If it is, I would highly recommend looking into a later model (90s) starter for your engine/transmission combination. Ford changed to a PMGR (Permanent Magnet Gear Reduction) starter that cranks much better with less current.

No need to buy an overpriced "performance" starter when the factory already has one. There is a small bit of rewiring needed at the relay on the inner fender.

[mat in tn]

lets not brush over the high idle. it is also a symptom of advanced timing. get a timing light on it. that is step one. what is it running at? then what does it run at with advance undone? this being an 84 it should have very basic fuel and ignition.