Help! Engine wont start and random high idle at speed

[Cowboy777]

Hey guys i just got my Bronco II (2.9 manual) five days ago
and it broke down on me on the freeway. Engine
Turns over fine but it won't start. I noticed when i was driving that if i took it out of gear it would idle pretty high, till i got down to 20mph then the idle would go back to Normal. Any idea why it would do that and if It May Be related to it not running or starting now? Im currently on the Side of the highway waiting for A friend with more tools, if i cant figure it out soon ill Tow it home, but if anyone sees this I would really Appreciate some helpvor advice cus i dont know this car very well yet. If it was my pickup im sure I'd be able to figure it out faster but oh well.
Thank you!

 

[Cowboy777]

UPDATE: im really confused as to what it could be now, i have fuel pressure from the pump and its got sparks on the plugs. Any ideas?

 

[CarsonChris]

Tps

 

[RonD]

High idle can be the IAC(idle air control) valve, it can be cleaned.

But that wouldn't cause the engine to die while driving.

The TPS(throttle position sensor) could, maybe tell the computer to cut fuel to idle level while you are driving, and on some EFI systems the TPS stops fuel injectors competely while coasting, foot off the gas, saves fuel, when RPM gets down to about 1,200 the injectors are restarted, but at idle levels.

No start now would lean towards no spark or no fuel.
You can spray starting fluid in the intake and turn over engine, if it fires then fuel is the problem, if it doesn't fire then spark is the problem.
Having fuel pressure doesn't mean injectors are putting it in the intake when they should.

A new distributor cost $70, an internal short or wobble can cause all sorts of issues, on again, off again, issues

The 2.9l engine is a non-interference engine, so timing chain/belt can skip or break without causing valve/piston damage, that would leave you with engine dieing and a no start, although having spark would mean distributor is turning.

 

[TexCaliBII]

Something else to check, just happened to me, is the intake gaskets. A massive vacuum leak will cause all kinds of havoc. I had an overheating issue I resolved and then it started being hard to start, dying and HIGH idle. New intake gaskets fixed me up.

 

[Cowboy777]

Thanks for all the advice guys! Sadly I wont be able to get to work on it till saterday, but I'll keep everything you said in mind and check it out. Hopefully i can identify the problem soon..

 

[Psychopete]

first thing I would do is spray starting fluid in the intake and see if it starts. it's possible you lost injector pulse, fuel pressure would be good, and would have spark, but no start. if it seems like it's injector pulse, see if you can get it to catch when you disconnect the MAP sensor. if it doesn't start on starting fluid, then timing is off somewhere. pull KOEO and CM codes

 

[Cowboy777]

I tried spraying starting fluid in and no go. But I did have To ask, the circular metal flap( i cant remember what its called) that is on the throttle body right at the intake, that is Supposed to open all the way when you give it full throttle right? Cus right now its barely opening it at all.