'86 Ranger 2.3 - Engine Cut-Out Symptom

[Mylesofsmyles]

It's an intermittent issue, that's never fully stalled the motor.

It was very intermittent before, a week or a few ago...now it's more often.

I'll be driving through town, low speed, low load, and the engine cuts out for only an instant at a time...seems similar to when my ignition switch failed, or a bad fuel pump.

Both Prepump, main pump, filter, FPR & injector o-rings replaced within the past 13 month.

Where and how can I start looking? What else could it be?

 

[RonD]

Intermittent is of course a pain to ID until total failure, but that is a pain as well.
Big 3
Compression
spark
fuel

I would rule out compression, unlikely for symptom

'86 2.3l will still have the TFI spark system with distributor.
Good read here on testing that system: http://www.therangerstation.com/tech_library/TFI_Diagnostic.shtml
Might find a marginal wire during testing

You could get/rent a fuel pressure gauge and test pressure.
If you have a 12v test light you could hook it up to the inertia switch in the passenger footwell, this would tell you if fuel pump power is being cut while driving, i.e. bad wire or Fuel Pump Relay.

 

[Mylesofsmyles]

I wondered about the TFI, but that's still only 13-14 months old...

I cleaned up cap & rotor...going to go check that fuel pump wires are on tight, and give it a try.

 

[RonD]

If you have a tachometer watch it closely during a stall out, yes RPMs drop during the stall but not by that much.
Tach gets it's signal from Coil "-" which is controlled by TFI, sudden drop on the meter(tach is an electric meter) could mean electrical issue.

And as a long shot, is this a manual or automatic?
If automatic could transmission be disengaging?
RPMs would go up though, if foot was on the gas pedal

 

[Mylesofsmyles]

Manual trans....M50d swap, back in May '14

Tach seems stable.

FYI...I did find a loose terminal on high pressure pump....tightened it, and secured.

With the cleaned cap & rotor, and tightened fuel pump terminal, car drove better for the first couple miles, now symptom is back and worse than ever

 

[Haywire6000]

Mine 93 would do this. It was a bad connection at the fuse box for the fuel pump.

 

[Mylesofsmyles]

Threw the parts cannon at it...

Just got back from the parts house with new wires, cap, rotor, coil & MAP sensor...

So far, so good.