Oh Crap - Stalling at speed

[traillme]

Thank you all beforehand for saving my life.

I have an 87 FJ with 350 and 5 speed. When I slow down quickly, either in neutral or downshifting, I lose most power. Lights/Radio still work, truck stalls, won't restart/turnover. If I am rolling I can pop the clutch and get it going.

Any ideas???

Thanks!

 

[Dynosoar]

Are you carburated or injected?

 

[brett76]

could your brushes on your alternator be going out? is it only when the rpms drop? if so thats what it could be. not charging the battery enough just getting it enuogh juice to keep going at higher rpms.

 

[traillme]

Injected

 

[AZLC]

Here's my experience with similar symptoms and 1970 bronco with efi conversion. Routinely stalled as clutch was in and coasting to light. There was also a surging sessation when I coasted at low speed (at idle) in gear. I do not have VSS hooked up.

I easily rule out volts and fuel pressure immediately as I have after gauges in cowl of hood with fuel gauge being mechanical. Both showed no problem when it puked.

The fix was to add a PCV from upper intake to lower which I had read was optional for this type of conversion. I do not know the technical reason why this would fix it, but it did.

It has not stalled since.

Good luck, if you find the root cause please post.
Thanks,
AZLC

 

[Dynosoar]

I would check 3 things. 1. Throtle plate adjustment 2 the air bleed motor somtimes called idle air control valve IACV(depending on what type of injection you are running) 3. check the TPS throtle position sensor is opereratin within spec.


And it never hurts to put in a new fuel filter.

Dynosoar