Guerillastyle
NAXJA Forum User
- Location
- SF
Update as of november problem has yet to re-arise. Seems like swapping out the TPS did the trick. From now on I keep an extra TPS under the back seat.
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Aw-4 Freeway speed "bucking"
- Thread starter Guerillastyle
- Start date
cruiser54
NAXJA Forum User
- Location
- Prescott, Az
Glad to hear.
8Mud
NAXJA Forum User
- Location
- Central Germany
Mine was doing the same thing, it turned out to be multiple issues. It was starving for fuel at peak torque 2200-2400 RPM and wouldn't run the RPM's anywhere near red line. It would buck like crazy at around 2200 RPM. I also initially thought it was a tyranny issue.
It was also over reving at start up.
I replaced the O2 sensor and fixed the O2 and engine temp.wiring where it was cooking on the front of the exhaust manifold (really hard to see). I had to disconnect the harness underneath and pull it up so I could repair it. I also rerouted it a little so it was farther from the manifold. Seemed to cure my bucking problems.
My TPS ground was loose in a splice under the insulation on the firewall. It took me forever to find that one. An ohm test on the TPS ground wire with the TPS disconnected wouldn't get the same ohm value two ties in a row and it got worse when I'd shake the injector and sensor harness near the firewall.
On another 87 I found where a wire was fatigued alll the way through under the insulation in the injector harness right where it makes the bend at the firewall. If all else fails, worth a look. I got lucky it was hard to find as the insulation was still in tact but the wire is broken.
It was also over reving at start up.
I replaced the O2 sensor and fixed the O2 and engine temp.wiring where it was cooking on the front of the exhaust manifold (really hard to see). I had to disconnect the harness underneath and pull it up so I could repair it. I also rerouted it a little so it was farther from the manifold. Seemed to cure my bucking problems.
My TPS ground was loose in a splice under the insulation on the firewall. It took me forever to find that one. An ohm test on the TPS ground wire with the TPS disconnected wouldn't get the same ohm value two ties in a row and it got worse when I'd shake the injector and sensor harness near the firewall.
On another 87 I found where a wire was fatigued alll the way through under the insulation in the injector harness right where it makes the bend at the firewall. If all else fails, worth a look. I got lucky it was hard to find as the insulation was still in tact but the wire is broken.
cruiser54
NAXJA Forum User
- Location
- Prescott, Az
8mud, that's the road I took to come up with this:
Cruiser’s Renix Sensor Ground Test
This sensor ground circuit affects the CTS, TPS, IAT, MAP, ECU and diagnostic connector grounds. It’s very important and not something to overlook in diagnosing your Renix Jeep as it is common for the harnesses to have poor crimps causing poor grounds. If any or all of the sensors do not have a good ground, the signal the ECU receives from these sensors is inaccurate.
Set your meter to measure Ohms. Be sure the key is in the OFF position. Using the positive (red) lead of your ohmmeter, probe the B terminal of the flat 3 wire connector of the TPS . The letters are embossed on the connector itself.
Touch the black lead of your meter to the negative battery post. Wiggle the wiring harness where it runs parallel to the valve cover and also near the MAP sensor mounted on the firewall. If you have an 87 or 88 with the C101 connector mounted on the firewall above the brake booster, wiggle it, too.
You want to see as close to 0 ohms of resistance as possible. And when wiggling the harnesses/connectors the resistance value should stay low. If there is a variance in the values when wiggling the wires, you have a poor crimp/connection in the wiring harness or a poor ground at the engine dipstick tube stud. On 87 and 88 models, you could have a poor connection at the C101 connector as well.
Revised 06/12/2012
at's how I came up with this:
Cruiser’s Renix Sensor Ground Test
This sensor ground circuit affects the CTS, TPS, IAT, MAP, ECU and diagnostic connector grounds. It’s very important and not something to overlook in diagnosing your Renix Jeep as it is common for the harnesses to have poor crimps causing poor grounds. If any or all of the sensors do not have a good ground, the signal the ECU receives from these sensors is inaccurate.
Set your meter to measure Ohms. Be sure the key is in the OFF position. Using the positive (red) lead of your ohmmeter, probe the B terminal of the flat 3 wire connector of the TPS . The letters are embossed on the connector itself.
Touch the black lead of your meter to the negative battery post. Wiggle the wiring harness where it runs parallel to the valve cover and also near the MAP sensor mounted on the firewall. If you have an 87 or 88 with the C101 connector mounted on the firewall above the brake booster, wiggle it, too.
You want to see as close to 0 ohms of resistance as possible. And when wiggling the harnesses/connectors the resistance value should stay low. If there is a variance in the values when wiggling the wires, you have a poor crimp/connection in the wiring harness or a poor ground at the engine dipstick tube stud. On 87 and 88 models, you could have a poor connection at the C101 connector as well.
Revised 06/12/2012
at's how I came up with this:
8Mud
NAXJA Forum User
- Location
- Central Germany
Like always, your write ups are thorough and concise.
- Location
- MilkyWay Galaxy
I must have the only working C-101 left on the planet! LOL
cruiser54
NAXJA Forum User
- Location
- Prescott, Az
My 87 and 88 still works but with the CPS bypass done and the sensor ground bypassed also.
