Serious lack of power!!

[ytt105]

I've got a 93 RR 3.9V8 with ZF auto.

Goes Ok but seems to lack the verve my other two Rangies had, (rebuilt 3.5 EFI with ZF, and a 3.9 EFI 5spd).

Saturday we did a test trip with our new Cub Supamatic Camper, (weighs about 700kgs fully loaded) from Canberra to The Cascades (near Cooma).

Boy am I disapointed now.

Got 33lts/100 on LPG, down to 40km/h on the highway up a couple of the big hills to Cooma and had to use low range to get up one hill into The Cascades. The road into The Cascades is suitable for 2wd and really is quite easy.

To make matters worse my mate towed the camper home with his 3.0l Pajero and didn't even know it was there!!

The performance didn't change with either LPG or petrol so I'm thinking its more fundamental, either camshaft or valves.

The engine has done 260,000kms and I don't think its been touched.

The other thing I thought of was the possibility of the auto slipping too much. Last week I changed the tranny fluid and it was filthy so obviously hadn't been maintained properly. The auto seem to work fine, changes gear beautifully, but just as we started on the drive to Cooma it seemed to slip a little, just like a slipping clutch, only did it the once.

Any and all suggestion welcome.

We are going on an eight week tour of NSW and QLD in four weeks time, I hope!!

[6.5 rangie]

Have you checked the timing lately?

[RaginRover]

I would say the cam is worn - 260,000k and hasn't had the heads off - push rod cams wear in rover motors

Tom

[C.A.Moseley]

If the motor seams to run fine (free rev or not towing) could be the bands in the box or torque converter. feed it to it on flat ground no load if it wants to pull but slips i'd say one of the above, if it just doesn't wanta play it'd be the previously mentioned cam or push rods

[justinC]

I'm with the camshaft etc. THEY WONT DO 260,000km, and will probably have some round lobes by now.

Has the engine got any vacuum at idle? Quickest way to check for cam wear , retarded ignition timing or leanness is with a good vacuum gauge. in park or neutral with all accessories off,You will want around 15 to 18 " of vacuum for a healthy motor.

Also, see if the distributor is even advancing, I have had quite afew Rangies and some disco's with seized advance mechanisms in the distributor, and as most of them have a perforated vacuum advance capsule anyway, it leaves no advance at all!!

JC

[up2nogood]

Sounds like time for a new timing set, cam and lifters.

[ytt105]

Yes it was the timing. All my fault, I've been progresively increasing the advance because LPG likes more advance. Apparently not as much as I gave it.
My previous LPG Rangie ended up with about 12 deg advance, so that is where I started this one, and kept advancing it until I could get no more on the vacuum gauge, about 15".When I connected the timing light I could even see the marks.
I've since found out that my model should have only 3 deg to start not 6 like my earlier model.
I've now got the timing set to about 5 deg and it goes like a rocket, even though the vacuum only reads 11".
Just drove it into the garage, very pleased that it flies, and then there was the unmistakable smell of coolant!!!
Damn little water pump hose!!
Better in the garage that west of Charters Towers I suppose!!
Anyway, thanks for all the help, and well done 6.5 rangie!

[6.5 rangie]

What do i win