2.9L & 3.0L V6 Tech General discussion of 2.9L and 3.0L V6 Ford Ranger engines.

Injectors not firing. 1994 3.0

  #1  
Old 06-20-2015
jalex88's Avatar
Member
Thread Starter
Join Date: Jun 2015
Location: my house, sc
Posts: 2
Likes: 0
Received 0 Likes on 0 Posts
Injectors not firing. 1994 3.0

Hey everyone. First post. I'm having problems with a 1994 Ranger 3.0 I bought recently. The truck sat for a few years before I bought it. I replaced the fuel pump, filter, plugs and wires, and starter solenoid and the truck was running great. After a week or so it got harder and harder to start and ran rougher and rougher until it wouldn't start at all.

I have fuel to the rails, and the plugs are firing. It will start with starting fluid. It looks as if the injectors aren't firing. There were two stored codes when I checked them. One for the MAF and one for the pick up coil. I don't remember the actual codes off of the top of my head and I can't find where I wrote them down.

If I'm understanding it correctly, the pickup coil is on the distributor and doubles as the camshaft sensor and the crankshaft sensor.

Is this more likely than a bad computer?

Is there anything else that would control the injectors? Does the ICM have anything to do with the injectors?
 
  #2  
Old 06-20-2015
RonD's Avatar
RF Veteran
iTrader: (1)
Join Date: Jan 2014
Location: Vancouver, BC
Posts: 30,654
Received 2,819 Likes on 2,585 Posts
1994 3.0l still had distributor and TFI spark system, yes, TFI module(ICM) sends a PIP(pulse) to computer to time fuel injectors with spark.

TFI doesn't need computer to run spark, but computer needs TFI pulse to run injectors.

Good read here on TFI system and checks you can do: Ford EEC-IV/TFI-IV Electronic Engine Control Troubleshooting

All fuel injection computers have a way for the driver to shut off fuel injectors.
This is there to "Clear a Flooded Engine"
The TPS(throttle position sensor) sends computer 1 volt when key is on and your foot is off the gas pedal, if you press the gas pedal to the floor the TPS sends computer 4.5 volts or higher.
If TPS sends computer 4.5volts and RPMs are 0(key on/engine off) the computer will turn off fuel injectors until TPS voltage is below 4.5v.
This allows the driver to crank the engine and clear it out if flooded.

BUT........if TPS(or it's wires) should short out and send 4.5volts all the time............no fuel injectors, so no start.
Unplug TPS and see if engine starts.

top wire on TPS should read 5volts
center wire, below 1v throttle closed, above 4.5v throttle wide open
lower wire is ground
 
  #3  
Old 06-20-2015
jalex88's Avatar
Member
Thread Starter
Join Date: Jun 2015
Location: my house, sc
Posts: 2
Likes: 0
Received 0 Likes on 0 Posts
Unplugging the tps doesn't change anything. I don't have a lot of time now, but I'll read the link you posted today or tomorrow. Thanks.
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
ranger1992
General Technical & Electrical
2
09-07-2012 12:42 AM
robuga
SOHC - 2.3L & 2.5L Lima Engines
4
11-15-2010 06:51 AM
papperbob1
2.9L & 3.0L V6 Tech
1
11-01-2010 08:44 PM
8-ball
2.3L & 2.5L I4 Tech
22
08-19-2008 06:35 PM
CaliGold
SOHC - 2.3L & 2.5L Lima Engines
5
09-03-2006 12:19 AM


Thread Tools
Search this Thread
Quick Reply: Injectors not firing. 1994 3.0



All times are GMT -6. The time now is 06:26 PM.