my 95 2.5 has developed a issue where its hard to cold start, then when it does its sounds bogged down till i give it enough gas to overcome it.....runs fine after.....any ideas?
Suddenly hard to start when cold
- Thread starter f4u5t
- Start date
there is a random "check Engine Light" which Autozone says they can not scan cause it is ODB1, and it is Fuel Injected
Flyer58
YJ Addict
The friendly autoparts places are not needed. Here's how you can check them..
A chart showing all OBD I codes for Jeep vehicles.
This method is used to retrieve OBD I and OBD II diagnostic trouble codes from your YJ, TJ, XJ, ZJ, and early WJ Jeep models.
- Insert the key into the ignition
- Turn the ignition On-Off-On-Off-On within 5 seconds
- Record the 2-digit DTC as displayed by the flashing MIL
| 11 | No crank reference signal detected during engine cranking. Intermittent loss of either camshaft or crankshaft position sensor. |
| 12 | Positive battery input to PCM was disconnected within the last 50 Key-on cycles. |
| 13 | No difference recognized between the engine MAP reading and the barometric (atmosphere) pressure reading from start-up. |
| 14 | MAP sensor input above or below acceptable voltage. 5 volt output to MAP sensor open. |
| 15 | No vehicle speed sensor signal detected during driving load conditions. |
| 17 | Engine did not reach operating temperature within acceptable limits |
| 21 | Upstream oxygen sensor response slower than minimum required switching frequency. Upstream oxygen sensor heating element circuit malfunction. Downstream oxygen sensor heating element circuit malfunction. Downstream oxygen sensor input voltage maintained above the normal operating range. Oxygen sensor voltage too low, tested after cold start. (Upstream or Downstream) Left oxygen sensor input voltage maintained above the normal operating temperature. |
| 22 | Engine coolant temperature sensor above or below acceptable voltage. |
| 23 | Intake air temperature sensor input above or below acceptable voltage. |
| 24 | Throttle position sensor input above or below acceptable voltage. TPS signal does not correlate to MAP sensor. |
| 25 | A shorted or open condition detected in one or more of the idle air control motor circuits. Actual idle speed does not equal target idle speed. |
| 27 | Injector #1 thru 6, or any combination of individual injectors driver does not respond properly to the control signal. |
| 31 | An open or shorted condition detected in the A/C clutch relay circuit. Insufficient or excessive vapor flow detected during fuel evaporation emission system operation. |
| 33 | An open or shorted condition detected in the duty cycle purge solenoid circuit. (A/C clutch relay circuit) |
| 34 | An open or shorted condition detected in the Speed Control vacuum or vent solenoid circuits. Speed control switch input below the minimum acceptable voltage. |
| 37 | Relationship between engine speed and vehicle speed indicates no torque converter clutch engagement. An open or shorted condition detected in the torque converter part throttle unlock solenoid control circuit. Incorrect input state detected for the Park/Neutral switch. Auto only. |
| 41 | An open or shorted condition in the generator field control circuit. |
| 42 | An open or shorted condition detected in the auto shutdown relay circuit. An open condition detected in the ASD relay output circuit. An open or shorted condition detected in the fuel pump relay control circuit. An open circuit between PCM and fuel gauge sending unit. Circuit shorted to voltage between PCM and fuel gauge sending unit. No movement of fuel level sender detected. |
| 43 | Peak primary circuit current not achieved with maximum dwell time. Misfire detected in one or more cylinders 1 thru 6. (4 and 6 cyls.) |
| 44 | Battery temperature sensor in voltage above or below acceptable range. |
| 46 | Battery voltage sense input above target charging voltage during engine operation. |
| 47 | Battery voltage sense input below target charging during engine operation. Also, no significant change detected in battery voltage during active test of generator output circuit. |
| 51 | A lean air/fuel mixture has been indicated by an abnormally rich correction factor. |
| 52 | A rich air/fuel mixture has been indicated by an abnormally rich correction factor. |
| 53 | PCM Internal fault condition detected. |
| 54 | No camshaft signal detected during engine cranking. |
| 55 | Completion of fault code display on Check Engine lamp. |
| 62 | PCM Failure to update service reminder indicator |
| 63 | Unsuccessful attempt to write to an EEPROM location by the PCM. |
| 64 | Catalyst efficiency below required level. (Same as code 72) |
| 65 | Power steering high pressure seen at high speed. (2.5L only) |
| 72 | Catalyst efficiency below required level. (Same as code 64) |
| 77 | Malfunction detected with poser feed to speed control servo solenoids |
Thank you, I get..
already replaced the pigtails, i guess its time for new injectors....
any recommendations?
| 27 | Injector #1 thru 6, or any combination of individual injectors driver does not respond properly to the control signal. |
already replaced the pigtails, i guess its time for new injectors....
any recommendations?
Flyer58
YJ Addict
I hope someone here can help with new injectors because I spent days researching for four new ones for my 2.5L and never found a good answer.
The key issue is finding a matching flow rate for the fuel rail pressure. Some argue don't worry because the computer will detect any changes and make adjustments while others say the computer is slow and not always right so initial performance will be ok/better but MPG's suffer and the computer wears out faster. This all sounds plausible but I can't find anything to back it up.
Identical replacements are hard to find and much more expensive than somewhat matching ones on the market. Bosch and others have several sets with four spray nozzles instead of the OEM with one but then we get into that issue with fuel flow and the conversations keep going in circles about which is better.
Testing:
Before you go any further you can do a simple test of the electric coil inside each injector with an ohm meter and that may isolate one or all injectors as not working properly.
Simply check the ohm resistance by probing the two pins on the injector. The YJ factory spec calls for 14.5 ohms +- 1.2 ohms. Easy, you only remove the connector and keep the injector in place.
Mine all checked within specs when I rebuilt the engine so I just cleaned them reused them.
They are all 4 roughly 16 ohms, but that would only show me a bad coil, not a blocked injector...correct?
Flyer58
YJ Addict
Yes that's correct. I just sprayed brake cleaner in mine. I don't know how bad they were to begin with