Fuel efficiently

[Shiggins]

Originally Posted by Shiggins

So I have the new 02 sensors in ( this solved the surging problem),new air filter, new fuel
Filter, new 777 injectors and cleaned the throttle body and sensors.

It looks like the fuel efficiency is going a bit better but I still want to do everything that I can to help it. I can't remember if i replaced the spark plugs and leeds when I first got the jeep 2 years ago so I'm considering changing them do I need to gap them or should that already be done if I get the correct plugs? The other thing is the dizzy cap and rotor. The one I have looks to be in good Condition. It's clean and I can't see any burn or shock marks on it. Is it necessary to replace if it looks in good condition?

Any opinions on this quote guys?

[anthonygubbin]

Originally Posted by Shiggins

Any opinions on this quote guys?

If the plugs are 2 years old its time to replace them regardless. If its missing after you swap the plugs, then get a new cap. For some reason I have found the dizzy caps wear out on mine. Not so much the contacts but they start to arc out after a couple of years. You can hear it tick on mine when the cap goes but only if you know what to listen for. I don't so I rely on a mech to tell me its buggard.

Regards A

[Capt. Crunch]

Originally Posted by junglejuice

As I specified this was on an OBD1 engine and yes it made a difference but so did the TBS.
Mine would ping, badly even when empty on the slightest incline when the temp was moderately warm, add the trailer and it was terrible which made climbing hills difficult when trying to minimise the pinging.
Add the TBS and the pinging disappeared for a while but eventually it came back but slightly less pronounced.
The I added the 99 manifold and TBS and then the pinging disappeared altogether, even when doing the OTT up Cape York in the heat up there towing 1t with the Xj heavily loaded it still didn't ping, not once.
I had a few members here tell me that the TBS catergorically does not work so as an experiment I removed it just before my missus went out in it (it's her daily driver), when she got home she proceeded to tell me that there was something wrong with the brakes as they must be on as the car was sluggish.
I then refited it and upon return she informed me that the brakes were all good again!!
I have to state that my OBD1 engine was down on compression, see this image for a comparison between my original OBD1 and the replacement OBD2 engines...


Also of note that the best ever milage I acheived to date (measured) was with the OBD1 engine, 99 intake, TBS, snorkel, 3.73:1 diff gears, stock 225/75's empty on the highway I got 10.1l/100 for a 100km trip.

Once I fitted the OBD2 engine (still OBD1 PCM, 99 intake TBS etc) my performance increased but my fuel consumption increased once over 100kmh (quite noticable) but since changing to the OBD2 PCM on a recent trip of approx 650km I noticed despite sitting on 110kmh where allowed I actually used less fuel (according to gauge position) then previously for the same trip at 100kmh (stock 97 manifold, no TBS).
I have yet to try the 99 intake with and without the TBS with the OBD2 PCM and I will also be trying a set of 777 injectors as well when I get a chance...

I used dodge neon injectors for mine and it also stopped pinging on 91 completely. I do still feel a noticeable difference in power between 91 and 95.

in terms of economy on daily driving though what was the difference between 99 intake and stock intake (as in numbers) more than .5km/l?

[COFFMAN]

Originally Posted by anthonygubbin

If the plugs are 2 years old its time to replace them regardless. If its missing after you swap the plugs, then get a new cap. For some reason I have found the dizzy caps wear out on mine. Not so much the contacts but they start to arc out after a couple of years. You can hear it tick on mine when the cap goes but only if you know what to listen for. I don't so I rely on a mech to tell me its buggard.

Regards A

WTF.......... man you must be on some good shite....

[junglejuice]

Originally Posted by Capt. Crunch

I used dodge neon injectors for mine and it also stopped pinging on 91 completely. I do still feel a noticeable difference in power between 91 and 95.

in terms of economy on daily driving though what was the difference between 99 intake and stock intake (as in numbers) more than .5km/l?

Hard to pin point exactly, best I got when stock around 14's (highway) compared to 10.1, same engine, same PCM but extractors, lower diff gears, removed roof racks, snorkel, new O2 etc but not only better economy but better performance.

Real world heavy loaded consumption with full length roof rack, roof pod, loaded interior with the afore mentioned mods with the OBD2 engine was 12.5l/100 but it's now better again without the manifold and TBS but the correct PCM....

[anthonygubbin]

Originally Posted by COFFMAN

WTF.......... man you must be on some good shite....

Which part don't you understand????? Standard plugs are normally good for 50k. As for the cap I can't work out why there is any confusion. Unless your referring to the ticking because yes I agree I can't tell if it is ticking unless someone give me the stethoscope to listen to it like has been done in the past.

Regards A

[bruggz351]

Originally Posted by anthonygubbin

We struggle to get Caltex 98 over here but even Caltex 95 gets me better economy than any other brand that includes BP 98. Funny thing is an friend swears her 07 Lancer gets better economy using at least 95 and it too has to be Caltex. This I know is odd considering all the fuel is supposed to come out of the same tank at the refinery.

Regards A

Thats it AG. I've been told this by truck drivers, and others. Also read on the interwebs. Go figure????

But the XJ doesn't lie.
Any other brand and the motor runs bad. We tried Shell Optimax 98 and same story. Ran bad, fuel economy dropped.

When we change, we use at least 3 to 4 tank fulls to get a true indication.
Ampol is the same... and everytime we use Ethinol blends, it mucks every frukcing thing up and costs us a small fortune to clean the shiteness out of the sysem.....
Also stay away from independants, unfortunantly, as most of the time we have no joy the fuels from these either.
Some times though, we have no choice about the fuel, depending where we are, but the occassional tank full doesn't usually effect things that badly.

I reckon the ol' beast is probably due for an ignition service too. Might helps a little...