Battling my 97

[hairyibis]

Hi All,
New to the forum, but I have been using this for a while now, so thank you! I have a 1997 Wrangler 4.0 manual trans with 130K on the clock here are my symptoms:

Random Stalling, seems like a loss of fuel pressure but I have 46psi on the rail
Airbag light
CEL P0107: Everytime the computer throws a code it is this
Stalling especially after engine breaking or coming to a stop
Oil pressure randomly drops, and a check gauges immediately after(probably sending unit)
Engine cutting out instantly and regaining power again

What I've replacednot necessarily mopar as I couldn't get them)

TPS
IAC
MAP sensor
Oil pressure sending unit
Upstream O2 sensor(Bosch)
Spark plugs
Battery
Cap and rotor
Crankshaft position sensor
Camshaft position sensor
Ignition coil

What I've done:
I sent my computer to Wranglerfix and they said nothing was wrong with it
Checked cylinder compression and it checks out
I cleaned every ground I could find in the engine bay
I chased all of the wires from the throttle body to the computer. Everything looks good there but I did rewire a few of the splices that looked like "melted plastic'
Grounds to all sensors read 0 ohms with my mutlimeter
Ive checked both fuel pressure and oil pressure with a mechanical gauge
I pulled the instrument cluster and applied dielectric grease to connections
The distibutor has some play in it so I ordered a new one that'll be my next replacement item

Not sure where to go next, any suggestions would be greatly appreciated. At this point I believe there is something wrong with the computer,
and throwing parts at it is getting ridiculous. Thanks!

 

[Chris]

Hi All,
New to the forum, but I have been using this for a while now, so thank you! I have a 1997 Wrangler 4.0 manual trans with 130K on the clock here are my symptoms:

Random Stalling, seems like a loss of fuel pressure but I have 46psi on the rail
Airbag light
CEL P0107: Everytime the computer throws a code it is this
Stalling especially after engine breaking or coming to a stop
Oil pressure randomly drops, and a check gauges immediately after(probably sending unit)
Engine cutting out instantly and regaining power again

What I've replacednot necessarily mopar as I couldn't get them)

TPS
IAC
MAP sensor
Oil pressure sending unit
Upstream O2 sensor(Bosch)
Spark plugs
Battery
Cap and rotor
Crankshaft position sensor
Camshaft position sensor
Ignition coil

What I've done:
I sent my computer to Wranglerfix and they said nothing was wrong with it
Checked cylinder compression and it checks out
I cleaned every ground I could find in the engine bay
I chased all of the wires from the throttle body to the computer. Everything looks good there but I did rewire a few of the splices that looked like "melted plastic'
Grounds to all sensors read 0 ohms with my mutlimeter
Ive checked both fuel pressure and oil pressure with a mechanical gauge
I pulled the instrument cluster and applied dielectric grease to connections
The distibutor has some play in it so I ordered a new one that'll be my next replacement item

Not sure where to go next, any suggestions would be greatly appreciated. At this point I believe there is something wrong with the computer,
and throwing parts at it is getting ridiculous. Thanks!

The P0107 code specifically points to a problem with the MAP sensor circuit, which you’ve already replaced. However, since the issue persists, it's worth double-checking the wiring and connectors leading to the MAP sensor. Since you mentioned you rewired some melted splices, make sure there are no other damaged wires or poor connections that could be causing intermittency.

Here are a few additional suggestions to consider:

Check the Fuel Pump: Even with 46 psi, sometimes the fuel pump can deliver inconsistent pressure under load. It may be worth testing the fuel pump's behavior during driving conditions.

Examine the Crankshaft and Camshaft Sensors: Although you replaced these, ensure they’re in good working order and the wiring is intact. Sometimes, these can act up intermittently if not seated correctly.

Inspect the Computer Grounds: You've checked grounds, but make sure the computer itself has a good ground connection. A poor ground could cause erratic behavior.

Check for Vacuum Leaks: An unmetered air leak can cause issues that might mimic a fuel-related problem. Inspect the intake manifold, vacuum hoses, and gaskets.

Look for Intermittent Electrical Issues: Given your symptoms, an intermittent electrical issue could also be involved, such as a bad relay or a short somewhere in the wiring harness.

Revisit the Instrument Cluster: Since you've worked on it, ensure the connections there are solid as well, since malfunctioning gauges could lead to incorrect readings of oil pressure or other performance indicators.

I hope this helps point you in the right direction. Keep us updated on your progress, and good luck with the troubleshooting!

 

[lBasket]

The P0107 code specifically points to a problem with the MAP sensor circuit, which you’ve already replaced. However, since the issue persists, it's worth double-checking the wiring and connectors leading to the MAP sensor. Since you mentioned you rewired some melted splices, make sure there are no other damaged wires or poor connections that could be causing intermittency.

Here are a few additional suggestions to consider:

Check the Fuel Pump: Even with 46 psi, sometimes the fuel pump can deliver inconsistent pressure under load. It may be worth testing the fuel pump's behavior during driving conditions.

Examine the Crankshaft and Camshaft Sensors: Although you replaced these, ensure they’re in good working order and the wiring is intact. Sometimes, these can act up intermittently if not seated correctly.

Inspect the Computer Grounds: You've checked grounds, but make sure the computer itself has a good ground connection. A poor ground could cause erratic behavior.

Check for Vacuum Leaks: An unmetered air leak can cause issues that might mimic a fuel-related problem. Inspect the intake manifold, vacuum hoses, and gaskets.

Look for Intermittent Electrical Issues: Given your symptoms, an intermittent electrical issue could also be involved, such as a bad relay or a short somewhere in the wiring harness.

Revisit the Instrument Cluster: Since you've worked on it, ensure the connections there are solid as well, since malfunctioning gauges could lead to incorrect readings of oil pressure or other performance indicators.

I hope this helps point you in the right direction. Keep us updated on your progress, and good luck with the troubleshooting!

Thanks Chrisbot

 

[Wildman]

P0107 is your MAP sensor

The code P0107 indicates a problem with the Manifold Absolute Pressure (MAP) sensor or the barometric pressure sensor circuit, specifically that the voltage being read by the engine computer is too low.

Chris beat me to it...

But based on that it's dying when braking/coming to a stop I'd look at your brake booster leaking first then at some other vacuum leak..

 

[macleanflood]

I'd be reading live ODB data or logging as you drive. A $30 ODB Bluetooth dongle and Torque Lite will accomplish this. Watch the PIDs for the MAP, fuel trims, voltage, O2 sensor voltage.

I'd also get that fuel pressure gauge rigged up so you can watch it while driving.

-Mac

 

[RMETeeJay]

Welcome! That code can be caused by a vacuum leak. You can build a DIY smoke tester with an old soldering iron.

Hold on to your old sensors, some MOPAR ones are NLA.

 

[hairyibis]

The P0107 code specifically points to a problem with the MAP sensor circuit, which you’ve already replaced. However, since the issue persists, it's worth double-checking the wiring and connectors leading to the MAP sensor. Since you mentioned you rewired some melted splices, make sure there are no other damaged wires or poor connections that could be causing intermittency.

Here are a few additional suggestions to consider:

Check the Fuel Pump: Even with 46 psi, sometimes the fuel pump can deliver inconsistent pressure under load. It may be worth testing the fuel pump's behavior during driving conditions.

Examine the Crankshaft and Camshaft Sensors: Although you replaced these, ensure they’re in good working order and the wiring is intact. Sometimes, these can act up intermittently if not seated correctly.

Inspect the Computer Grounds: You've checked grounds, but make sure the computer itself has a good ground connection. A poor ground could cause erratic behavior.

Check for Vacuum Leaks: An unmetered air leak can cause issues that might mimic a fuel-related problem. Inspect the intake manifold, vacuum hoses, and gaskets.

Look for Intermittent Electrical Issues: Given your symptoms, an intermittent electrical issue could also be involved, such as a bad relay or a short somewhere in the wiring harness.

Revisit the Instrument Cluster: Since you've worked on it, ensure the connections there are solid as well, since malfunctioning gauges could lead to incorrect readings of oil pressure or other performance indicators.

I hope this helps point you in the right direction. Keep us updated on your progress, and good luck with the troubleshooting!

Thanks for your suggestions! I completed a few of them and rewired another splice with some possible results. I had it running for about a half hour without any stalling or check engine light. I'll update in the near future with results.

 

[hairyibis]

After chasing some more wires, I rewired another splice. I think it is S133 from the FSM. It is for all of the sensor grounds in between the oil pressure sending unit and the firewall. I haven't been able to reproduce a stall or another code after a good bit of driving...
Additionally I could not find a vacuum leak with the propane method. Grounds from the ECU are good, and I swapped the ASD relay
for the fuel pump relay. Haven't tested them yet. Replaced distributor and a new IAC(my second) and that seems to have fixed my
stalling/oil pressure light when coming to a stop or returning to idle. The first one was TRQ from rockauto and apparently faulty out of the
box. I also put my original MAP sensor back in since it wasn't ever a problem.
I will take it for another longer drive to confirm but I am feeling closer to solving my issues. Thanks for all of the advice!

 

[hairyibis]

Took it up into the hills today and I am back to the drawing board...no random stalling or CEL though so that is a positive.
After engine breaking down a hill and clutch in come to a stop it still tries to stall. Another bad IAC, I don't know it was a duralast part.
I wonder if the plunger is getting stuck in the throttle body, it is an aftermarket throttle body. Giving it gas solves the problem but without
it will stall. Fuel pump diagnosing time I suppose...

 

[macleanflood]

Yeah I'm guessing you're fighting that aftermarket throttle body and that Duralast IAC isn't helping.

I have yet to see a viable replacement to the throttle body. Plenty of resources on how to o-ring the shaft.

-Mac

 

[barbaz]

After chasing some more wires, I rewired another splice. I think it is S133 from the FSM. It is for all of the sensor grounds in between the oil pressure sending unit and the firewall. I haven't been able to reproduce a stall or another code after a good bit of driving...
Additionally I could not find a vacuum leak with the propane method. Grounds from the ECU are good, and I swapped the ASD relay
for the fuel pump relay. Haven't tested them yet. Replaced distributor and a new IAC(my second) and that seems to have fixed my
stalling/oil pressure light when coming to a stop or returning to idle. The first one was TRQ from rockauto and apparently faulty out of the
box. I also put my original MAP sensor back in since it wasn't ever a problem.
I will take it for another longer drive to confirm but I am feeling closer to solving my issues. Thanks for all of the advice!

Hi @hairyibis ! maybe do you have some photo of the location of this S133? It's different year from my '03 but I hope that they are in a similar location
thanks in advance!
D