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12j.... even more sluggish than normal...is that possible??


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Hi All

Have a 12j in a 90..... I am realistic...it's slow...but bear with me.

I used to have a 12j in an xMod 110, and that was nippier than this one.... admittedly that would have had a lower ratio transfer box.

The 90 behaves well, starts first time, no smoke.....now after changing the head gasket...

Thought the head gasket may have been the issue...it did need changing....but now seems to have lost more performance!

Had the diesel pump reconditioned by Automarine a couple of years back, replaced cam belt and lift pump etc

Uses no water and the oils stays pretty clean...for a Landy Diesel !

Performance..... given time it gets up to about 60 on a dual carriageway...happy with that....... but on normal road it can lose speed very quickly on a very slight gradient...seriously hardly noticeable slope...and you rapidly have to drop down through the gears......no real revs....not expecting a screamer but the power seems to be between 800rpm and about 2000 max...then falls flat

Throttle stop is ok, can get full throttle and revs fine with no load.

It just feels sort of strangled....I know they all do, but this more so.  I did a lot of miles in the 110 so know roughly how it should feel.

I have 2 thoughts..... or 3 actually!

Is the pump a bit retarded??   Retarded ignition gives a bit more bottom end on a petrol...but diesel??

Could the lift pump be not delivering enough diesel??

Or could the injectors need cleaning or replacing...reconditioning.

I used the best 4 from a 12j and 19j ( both same part number ) when I first rebuilt the engine a couple of years ago.

First one looks a bit sooty but had 2 copper washers ( that was me 😞 )  think the oil on the third one was just from during the strip down....took these pics during the HG change.

Any ideas all..... other than put a tdi in...... if it ran like my 110 did I would be entirely happy...doesn't do a lot of miles, minimal towing except a chain harrow and that's in low ratio!

Ironically this starts way quicker than the 110 did!  that was 10 elephants on the glow plugs and a bit of grinding from the starter...this is 10 elephants and instant start.

injectors.jpg

Edited by gbmoto
typo
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Hi Gazzar

It's just a standard 1.41:1,   MOD 110's are a bit lower..... I do have one of those in the garage actually!

Injector pump is good, compression seems fine, no smoke when running, bores show hone marks and piston ring gaps were fine 2 years and not many miles ago...plus recon head.

The 12j and 19j have a belt, and I changed that when the pump went in, again 2 years and not many miles ago.

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Lift pump , I've recently added an inline electric pump to two Tdi 90's to complement the mechanical lift pump . In both cases smoother and more power driving normally . They are not expensive and fit well under the seatbox beside the tank .

cheers

Steve b

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5 hours ago, steve b said:

Lift pump , I've recently added an inline electric pump to two Tdi 90's to complement the mechanical lift pump . In both cases smoother and more power driving normally . They are not expensive and fit well under the seatbox beside the tank .

cheers

Steve b

What pumps did you use if you don't mind me asking?

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I think it could be a combination of things adding up. I would get the injectors checked out (but if it isn't smokey they are likely to be fine). Check the timing, both cam and pump. Check the valve clearances. Get a new fuel lift pump (a quality mechanical one should deliver plenty of fuel to the injection pump). Change the fuel filter and air filter. Are you using the correct grade of engine oil? 

Have you had someone sit in the drivers seat with their foot right down on the accelerator pedal while you check that the lever on the pump moves all the way?

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Thanks All, actually I had been wondering about adding an electric pump, seems to be a popular mod over in the USA, although it could be pasting over another problem i guess.

I have checked out all the other stuff, new lift pump etc when I did the rebuild 2 years ago ( and not many miles )

Probably should change the fuel filter actually...may have been some stuff in the tank as it had been sitting for a while before I got it going again, but again not been in there for long.

Have checked and def getting full throttle..... almost disappointed it checked out ok as it really felt like that was the problem

It has the correct oil, but agree, it is just like it is running with thick tar as a lubricant!!...... I am erring towards fuel feed at the moment.

All your suggestions are a great help..... even if it confirms I haven't missed anything obvious... please keep them coming... I am flummoxed!

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Poorly performing diesels are usually the result of not enough air or not enough diesel.

My first ports of call would be to see how it runs without the fuel cap and to change both air and fuel filters.

Mo

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4 minutes ago, gbmoto said:

I have checked out all the other stuff, new lift pump etc when I did the rebuild 2 years ago ( and not many miles )

Probably should change the fuel filter actually...may have been some stuff in the tank as it had been sitting for a while before I got it going again, but again not been in there for long.

I think your problem is in here. Give it a thorough service renewing oil and all filters for quality parts. Check and adjust where necessary valve clearance and timing as 2 years is plenty of time for something to have wandered off from where it should be.

2 years is also plenty of time for your mechanical lift pump to have failed or start to fail. I would just replace your current one with a quality part such as Delphi.

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8 hours ago, Chicken Drumstick said:

What pumps did you use if you don't mind me asking?

Facet  - the first one was the same Facet type as used on RRC/110 V8 an the second was a solid state Facet the owner obtained online . Both mounted on isomounts to underside of seatbox near the tank . I too have always advocated fixing the standard set up - good pipework and filter and new lift pump but of late it seems mechanical lift pumps are a technology too far for modern manufacturers . Iirc it was Boydie that did this years ago and commented then on smoother engine and better performance .

The last one I added an e-pump to had a Delphi OEM lift pump a year ago (and only 2k miles) that failed on the road , I have to wonder if these repeated Lift pump failures are related modern diesel make up .

cheers

Steve b

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All the service stuff (apart for fuel filter) was done a couple of weeks ago when I did the head gasket swop, but I am drawn to the electric fuel pump anyway, what circuit would you wire it in to Steve?

I am intrigued by fuel cap, have had exactly that on a couple of motorbikes...... but doesn't the Landy have a separate vent ?    Although I guess that could be blocked a bit too.... an avenue I hadn't considered.

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^^^this along with checking the timing and adjustments. Its surprising what a difference a nice clean fuel filter can make. Until these are complete you aren't at the modification to the fuel transfer stage. 

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Indeed , do the fuel filter - a good chance to see how powerful the lift pump is filling the new one and by all means check the FIP timing . retarded will make it gutless . When correct it should have a slight diesel knock when revved and a very small amount of black smoke accelerating hard on the road .

The first one I did was the RRC type which picked up the ignition live on the FIP stop through a fused relay to pump . With the second ( a 200 Tdi converted 2.5 turbo 90 ) I found a spare white (ign. live) in the wiring loom plugs by the clutch pedal box and ran straight from that , the solid state one fitted to this one only takes ~5a .

I assume you have checked the air filter element is not soaked in oil which can happen ? If you have a raised air intake check for birds nests , Blue Tits love a snorkel ( fit a mesh guard)

cheers

Steve b

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Don't waste your time/money on an electric pump - can be beneficial on some setups but the standard lift pump draws more than enough to feed a 65hp diesel without breaking a sweat.

Yes swap the filter, check the gauze on the pump, do a compression check to see if there are anomalies, check good air flow from filter into manifold. 

Accurate timing makes a big difference with these engines, it may benefit from a slight advance.

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Thanks Again all, have ordered a filter, so will fit that, check tank venting and gauzes etc then test.

I don't think it has a sedimenter like the 110 but will have a look

Ironically was going for MOT on tuesday but the guy I use has had to isolate due to a family member with a temperature, so testing may be a little in the future as it expires in a couple of days!

Depending on how that works out may do a little advance.

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19 minutes ago, gbmoto said:

 

Ironically was going for MOT on tuesday but the guy I use has had to isolate due to a family member with a temperature, so testing may be a little in the future as it expires in a couple of days!

Depending on how that works out may do a little advance.

Are MOT test stations still open?  In Ireland the equivalent testing is postponed due to the virus. 

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2 hours ago, gbmoto said:

Although I hear we have a 6 month amnesty??

If your MOT expired after 1st April it will have been extended by six months automatically. Check the status using the Gov.uk website and it should be updated if the original expiry is soon.  

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  • 1 month later...

Hi All, thought I would do a quick update.

Yes, MOT not an issue...extended...yay!

Had the last week off so changed  diesel filter...element looked ok but there was a bit of silt in the base so probably worth doing.

Maybe a tiny bit better after??

Anyhow...for the time being leaving it as it is...it is the best starting Landy I have ever owned ( that's done it now 🙂 ) and actually gets from place to place OK.

I think the main difference between this and my old MOD 110 was the transfer box, being lower closed the gears up a bit.

Yesterday it did 3 and a half hours of chain harrowing quite happily and driving home did seem a little more peppy.

So will just regularly use it and appreciate it.

Many thanks for everyone's helpfull suggestions.

 

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25 minutes ago, gbmoto said:

Had the last week off so changed  diesel filter...element looked ok but there was a bit of silt in the base so probably worth doing.

Silt?! I would say that was a very worth while filter change! I swap mine every 12 months regardless. The filter also should trap any water that is lurking in the fuel from condensation in the metal tank. It's helps to keep the diesel tank full when not in regular use to stop condensation forming in the tank.

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