Welcome Visitor! Please take a few seconds and RICHARDG
New Member
- Joined
- Apr 27, 2014
- Messages
- 3
- Reaction score
- 0
- Points
- 0
- Vehicle Year
- 1990
- Make / Model
- ford
- Transmission
- Automatic
Hi all,
Here's the problem: Bronco II dies after running (or idleing) for EXACTLY 25-30min. Runs like a top (NO engine firing/"missing") with good idle & acceleration for 25-30 mins. then engine "lugs"/chugs (like spark or fuel starvation) & just dies. Does NOT blow any smoke, leak any oil. engine temperature is NORMAL. "check engine" light comes on after ~ 20min at idle, just before it dies 5 -10 min later at the 25 - 30 min mark.
IF I disconnect the vacuum hose that runs between the air filter & intake manifold then the "check engine" light DOES NOT come on BUT the engine still dies at the 25 - 30 min mark.
History & tech specs:
> 1990 Bronco II 2.9L fuel injected. 76K ORIGINAL miles
Engine DOES NOT have a MAF or EGR sensor.
Truck was garaged for ~ 10 yrs.
> New parts installed:
Fuel pump, fuel filter, FPR (fuel pressure regulator), air filter, plugs, plug wires, TFI (distributer ignition module) thermostat.
> Troubleshooting procedures & maintenance checks performed:
ACT sensor cleaned & resistance checked OK.
IAC cleaned
PCV cleaned & checked OK
TPS checked OK
Throttle body cleaned
Coil resistance checked & spark jump checked OK ( ~ 1"" + )
Distributer cap & rotor checked OK
Alternator voltage output IS STEADY ( DCv) checked OK @ ~ 13DCv at idle RPM. (output voltage DOES NOT INCREASE with higher RPM )
>Possible causes issues/& other miscellaneous symptoms identified so far:
Base Idle Adjustment - Cant set/get the engine to idle below ~ 1000 - 1,100 RPM ( factory spec is ~ 850 - 950RPM)
?? - RF headlight "dims" with right turn signal engaged (NO other light/turn signal dimming, NO engine RPM decrease/ dying)
??? - Alternator gets very warm (hot?) the longer the engine runs.
SOoooooo...... the question is...
Whats causing the engine to die ?
?? MAP sensor is bad ?
??? ECM malfunctioning ?
???? other ?
Any comments/help appreciated
Thanks
richard
Here's the problem: Bronco II dies after running (or idleing) for EXACTLY 25-30min. Runs like a top (NO engine firing/"missing") with good idle & acceleration for 25-30 mins. then engine "lugs"/chugs (like spark or fuel starvation) & just dies. Does NOT blow any smoke, leak any oil. engine temperature is NORMAL. "check engine" light comes on after ~ 20min at idle, just before it dies 5 -10 min later at the 25 - 30 min mark.
IF I disconnect the vacuum hose that runs between the air filter & intake manifold then the "check engine" light DOES NOT come on BUT the engine still dies at the 25 - 30 min mark.
History & tech specs:
> 1990 Bronco II 2.9L fuel injected. 76K ORIGINAL miles
Engine DOES NOT have a MAF or EGR sensor.
Truck was garaged for ~ 10 yrs.
> New parts installed:
Fuel pump, fuel filter, FPR (fuel pressure regulator), air filter, plugs, plug wires, TFI (distributer ignition module) thermostat.
> Troubleshooting procedures & maintenance checks performed:
ACT sensor cleaned & resistance checked OK.
IAC cleaned
PCV cleaned & checked OK
TPS checked OK
Throttle body cleaned
Coil resistance checked & spark jump checked OK ( ~ 1"" + )
Distributer cap & rotor checked OK
Alternator voltage output IS STEADY ( DCv) checked OK @ ~ 13DCv at idle RPM. (output voltage DOES NOT INCREASE with higher RPM )
>Possible causes issues/& other miscellaneous symptoms identified so far:
Base Idle Adjustment - Cant set/get the engine to idle below ~ 1000 - 1,100 RPM ( factory spec is ~ 850 - 950RPM)
?? - RF headlight "dims" with right turn signal engaged (NO other light/turn signal dimming, NO engine RPM decrease/ dying)
??? - Alternator gets very warm (hot?) the longer the engine runs.
SOoooooo...... the question is...
Whats causing the engine to die ?
?? MAP sensor is bad ?
??? ECM malfunctioning ?
???? other ?
Any comments/help appreciated
Thanks
richard
