Hi there! Need engine help pretty bad for my daily

[JT1296]

So when i start my truck in the morning it starts and idles normal for a few seconds and then itll either sputter and die or itll chugg like its running on a 3 cylinders until it backfires and revs to 3000 rpms... The check engine light is on but when i had the guys at autozone scan it their tool read it as a 2001 ford ranger 2wd. Last time they scanned it (a few months ago) it read correctly as a 1998 4×4 ranger... Any help or ideas on what to check would be much appreciated! Thank you for your time.
JT

 

[RonD]

2001 thing reads like scanner issue not computer issue.

You can get a bluetooth OBD2 reader for $35 that you use with a smartphone to watch live data while driving or read codes.
Works with any 1995 or newer North American car or truck, so worthwhile investment.

Google: bluetooth OBD2 reader

OK, back to the cold start issue

Could be ECT(engine coolant temp) sensor is "telling" computer the engine is already partially warmed up, so after startup computer leaves Choke mode and runs engine too Lean so it misses and stalls.
ECT sensor is about $8, so I would just change it on spec

There are TWO temp sensing devices on all fuel injected engines
ECT SENDER, 1 wire, used for dash board temp gauge, NOT computer
ECT SENSOR, 2 wires, used only by computer.

Make sure you get the SENSOR, not sender, parts guys often think they are the same thing.
Both of these are usually located near the thermostat housing.

Another thing it could be, since you don't mention how it runs warmed up, is that you are loosing fuel pressure when engine sits for a few hours.
When you turn on the key the computer only runs the fuel pump for 2 seconds, that will add 10-15psi of pressure to the fuel system.
'98 Ranger should have 65psi of pressure at the fuel rail/injectors, and it will hold that pressure for a few months when engine is off.

If pressure is leaking out and it is only 20psi after 6 hours then turning on the key once only gets you to 35psi and engine would struggle to stay running until pressure built up.

So try turning on the key, count to 3, and turn key off
Repeat this 3 times, 45psi minimum pressure, then try to start engine.

If it starts better then you are leaking pressure, on the Returnless system this would usually be the check valve inside the fuel pump.
Check valve is only used when pump is off so this wouldn't effect driving, only startup when enough pressure had leaked out.
If you smell gas then obviously a fuel line is leaking

 

[JT1296]

Thank you for the very detailed reply, i tried turning the key a few times like you said and it seems to run perfectly with no idle issues or anything! Thank you so very much

 

[RonD]

Good work

 

[enjr44]

Just a word of caution. Turning the key a few, three?, times is not a fix. It is masking the leaking check valve or fuel system (lines, filter, etc.).

If it is the check valve, it could go years that way (or not, on mine the not option left it stranded). If it is a fuel system leak (outside the tank) that needs to be fixed for safety.