Koenig
NAXJA Forum User
- Location
- BC, Canada
Hi guys!
OK, i'm starting to get extremely frustrated with my XJ
I've been trying for about a month now to track down this problem I am having. It is proving to be a hard one to track down. This is an 89 XJ w/ Renix 4.0l non-HO engine and AW4. Initially I thought it was my tranny slipping when the problem first surfaced at highway speeds in 4th (OD) gear. While accelerating slightly I would get a sudden lurch or jolt in the driveline. This was intermittent, but was definately happening when I was on the accelerator and never while coasting. Lately the problem has gotten a little worse, and on top of this jolting in 4th gear, I am also having problems going up steep hills and accelerating on level ground. The problem is not happening under normal city driving conditions, but when I need to get on the gas heavily (all the way to and INCLUDING WOT) I am getting an intermittent stumble and bogging down. While trying to accelerate heavily, the engine seems to waver back and forth between full power and very little power.
So here is what i've done up until this point.
- spent countless hours searching this forum for the magical solution!
- replaced TPS (adjusted it properly to 83%)
- replaced O2
- checked the CTS and MAT with voltemeter
- checked the CPS (reading ~265 ohms)
- checked all over for a vacuum leak
- cleaned the contacts for the balast resistor
- hit the cat to see if it's making noise (which is isn't)
I think that this problem is timing related. There is an intermittent pinging happening when i'm accelerating heavily. If the engine is suffering from pre-ignition, does this rule out a back fuel pump and a clogged up cat? I have a hard time believing that it is fuel related simply because under low-normal acceleration there is a lot of power and torque. I can also not understand how the XJ starts up and runs smooth (idle between 500-900rpm with maybe a 50rpm lope here and there, which I would say is normal for a 17yr old Jeep). It does not show any signs of this issue if you rev is while in neutral either.
Any help or ideas at all would be definately appreciated! Sorry about the long post!
I have a new CPS that I will be putting in this weekend, but I was always under the assumption that this sensor either works or doesn't...so i'm assuming that it won't fix the problem. I really thought the TPS and O2 sensor would fix it...now I don't know!
Koenig
1989 Jeep Cherokee Laredo
~140,000km 4.0L AW4 NP231
OK, i'm starting to get extremely frustrated with my XJ
I've been trying for about a month now to track down this problem I am having. It is proving to be a hard one to track down. This is an 89 XJ w/ Renix 4.0l non-HO engine and AW4. Initially I thought it was my tranny slipping when the problem first surfaced at highway speeds in 4th (OD) gear. While accelerating slightly I would get a sudden lurch or jolt in the driveline. This was intermittent, but was definately happening when I was on the accelerator and never while coasting. Lately the problem has gotten a little worse, and on top of this jolting in 4th gear, I am also having problems going up steep hills and accelerating on level ground. The problem is not happening under normal city driving conditions, but when I need to get on the gas heavily (all the way to and INCLUDING WOT) I am getting an intermittent stumble and bogging down. While trying to accelerate heavily, the engine seems to waver back and forth between full power and very little power.
So here is what i've done up until this point.
- spent countless hours searching this forum for the magical solution!
- replaced TPS (adjusted it properly to 83%)
- replaced O2
- checked the CTS and MAT with voltemeter
- checked the CPS (reading ~265 ohms)
- checked all over for a vacuum leak
- cleaned the contacts for the balast resistor
- hit the cat to see if it's making noise (which is isn't)
I think that this problem is timing related. There is an intermittent pinging happening when i'm accelerating heavily. If the engine is suffering from pre-ignition, does this rule out a back fuel pump and a clogged up cat? I have a hard time believing that it is fuel related simply because under low-normal acceleration there is a lot of power and torque. I can also not understand how the XJ starts up and runs smooth (idle between 500-900rpm with maybe a 50rpm lope here and there, which I would say is normal for a 17yr old Jeep). It does not show any signs of this issue if you rev is while in neutral either.
Any help or ideas at all would be definately appreciated! Sorry about the long post!
I have a new CPS that I will be putting in this weekend, but I was always under the assumption that this sensor either works or doesn't...so i'm assuming that it won't fix the problem. I really thought the TPS and O2 sensor would fix it...now I don't know!
Koenig
1989 Jeep Cherokee Laredo
~140,000km 4.0L AW4 NP231