97 Expedition, 5.4L hesitated during acceleration 40-45MPH. Check Engine light flashed, then stayed on. Would get up to 55-60MPH. All guages read ok. First trouble ever with this car.

fix misfire [s]

CJ5 Hesitates when accelerating - JeepsUnlimited

www.jeepsunlimited.com/.../showthread.php?...CJ5-Hesitates-when-accel...

Mar 29, 2006 - 19 posts - ‎13 authors
If it still hesitates I'd say it was a carburetor issue (accelerator pump, power valve..). If it is only acting up when accelerating (while driving) that would tell me it ... 1980 CJ5Renegade with 304 v8 .... The idle mixture screws were nearly 3 turns out, I think i have them somewhere around 2.5 turns right now.

97 TJ 2.5L hesitating and sputtering - JeepsUnlimited

www.jeepsunlimited.com/.../showthread.php?...97...hesitating...sputterin...

Dec 8, 2001 - 20 posts - ‎9 authors
Reving the engine in gear with the clutch in a bit would load the ... alot longer to warm up and tends to hesitate when pulling away from a ... Jeep rater score from the factory:26, today:238 ..... 92 XJ 155/80r13s and 17"s of lift.Missing: cj5

Hesitation on Acceleration... performance problems #1 ...

? 7:13
https://www.youtube.com/watch?v=0m4IiVzwjzE
Nov 17, 2013 - Uploaded by Luke Nodzo
Luke will explain why your car may be hesitating or sputtering on... +ameer aklil My 2012 2.5l Frontier does the same thing when it is in 3rd and ...

Check the ignition wires and the module

fuel pump? it is running lean (not enough fuel) or a leak in evap

CODE SCAN FOR FAULTY TPS SENSOR.IF TPS SENSOR BAD YOU WILL SEE CHECK ENGINE LIGHT FLASH ON.A BAD TPS SENSOR WILL CAUSE HESITATION DURING ACCELERATION. IF TPS SENSOR OKAY NO CHECK ENGINE LIGHT FLASHING. DIRTY FUEL INJECTORS AND STOPPED UP FUEL FILTER WILL CAUSE SAME PROBLEM.

When a 'check engine light' (MIL=Malfunction Indicator Lamp) is turned on, there is a DTC (Diagnostic Trouble Code) set/stored in the ECM/PCM (Engine Control Module/Powertrain Control Module). This code identifies which engine management system component/function experienced a malfunction. Once you pull/read this code, you may begin diagnosis.

check plugs wires and distributor....coil didn't fix it cause it wasn't the coil.

The check engine light is on because the computer has detected a fault in the system.It could be a sensor,wiring or bad connection.You have to get the codes read to find out what could be causing the problem.Most parts stores will do this for no fee at all.Hope this helps.Good luck.

Possible exhaust restriction.
Could be cat converter.
You can try and unhook the exhaust system and try it.
If the car will run a few minutes try a vacum guage hooked up to engine vacuum.
If you get a very low reading that would be your answer.

Ok, there are many issues here that you will need to inspect. I recommend changing the fuel filter and pump as well. this will fix the hesitation. the intake and exhaust manifold gaskets will need to be replaced as well. this will stop the backfiring.

I also recommend checking and running a teat on the PCV valve and inspect the PCV hose as well. it could have a leak or a small crack on it.

Check the air filter and change if needed. this will help with acceleration issues as well. Next, i would run a check on all plugs and the complete wire set as well. change if needed.

Inspect the injectors for leaks and lose wires. make sure they are in good condition. replace any injectors that isn't firing properly.

Ok, there are some sensors that you will need to check as well. i will list them below.

SENSOR CHECK LIST--

1. Check the O2 sensors for worn wires.
2. Check the MAFS(Mas Air Flow Sensors) Check for Damaged, Loose, or Faulty Mass Air Flow Sensor or Circuit.
3. Check the Air Cleaner Temperature Sensor. this sensor could be damaged ro have loose wires. check accordingly.
4. Check the Throttle Position Sensor. this device could be connected wrong or it may be faulty as well. replace if needed.

Be sure and inspect all the above and repair any problem spot you ruin across during your inspection.

Please rate and god bless:)