Suction Control Valve Removal

[Tractionman]

They were the good old days I remember Juddian, and my main experience of injectors, etc on hgv.
That's why I can't get my head around'modern improvements, and swapping bits round.
Old school I may be, but it all worked and for a very long time, not like some of the shyte now.
I don't know what went wrong with Toyota's design and testing, that wasn't obvious from the start, they obviously didn't do enough. Money again I suppose. Design it, build it, flog it and f**k it !

 

[GeekOKent]

The most weird thing happened today. Driving along at about 60mph, the 120 went into limp mode. I was about 15 miles from home, so decided it's worth going on. About 2 miles later the check-engine light came up, and the ATF temp light (?), and the truck cut out completely.

Pulled over to the side, had a poke under the hood - nothing leaking, nothing smelling burnt, plenty of diesel, filters are good, batteries are good. No tools or techstream , so couldn't really do anything. For giggles and shits, tried the ignition and everything came back on, and we drive home just fine, the truck smooth as ever.

Never happened before, but is this in line with the sort of problem you had @TonyP ? Mind you, it's not a cold day and the truck had done about 20 miles in the day already.

 

[TonyP]

Yup same experience I had. Typically when cold, but also in mid August driving to MotoGP. Was fine for 30miles and then went into limp mode. I got so good at restarting I didn't even need to pull over, knock it into neutral, turn ignition off for 2 secs, restart, back into drive and off we go..... lost maybe 15mph from 70

I suspect my issues were the injectors, but best start with the scv as that's whats most recommended from reading around

 

[GeekOKent]

Thanks.

I am at about 150k miles now, and as far as I can tell it's still running the injectors the truck was born with. So maybe time to think about a refurb set of those too.

Time to go look at the piggy bank.

 

[TonyP]

Yeah at 150k miles thats past the typical mileage when they get changed, most are are around 120k miles.

I think the quality of diesel used makes a difference, I have used cheap as supermarket stuff, so that couldn't have been good for the injectors....

 

[TonyP]

Well if you can do them yourself it's about £600 with all the bits and recon injectors where you send the old ones back on exchange....

 

[deryans]

yeah, it's un-kaizen (not like toyota) like to not have the SCV throw at least an upstream/downstream sensor code that can trace back to a root cause, was actually a guy in ireland knew the symptoms after I posted a short video and we replaced it, truck fine since then, 185K, think it's still on original injectors, had them checked a few months ago still within tolerances ----- for now.

 

[karl2000]

Does it record the original code that triggered the check engine light?

 

[deryans]

not that I can recall, it threw a crankshaft out of position first, then we looked at that, thought water damage, mech was suspicious, he was right, but we replaced cam pos sensor anyway, problem persisted, put back old sensor , tried numerous resets, got one fuel pressure out of tolerances, reset again, ECU suspected, another few days of diagnostics, resets and still persist, finally got her back after 4-5 days , drove it sparingly, then it happened again, said FFS, lets just replace the SCV and be done with it, all good since. then, and that was 6 months ago, tricky, not logical and confused codes. - you kind of have to have been there to see how difficult it is to pin this down, surprise as I said before, all good , SCV's cheap tbh, (they're basically a mech actuator to preserve fuel pressure, but they are a working precision item so will def wear out). ** workaround on a 120 that has a no-go code or a limp mode is to disconnect (-) lead from batterie and wait 30-60 seconds, this resets her and she's good to do, it was ok with an SCV, but I'd be using this seriously sparingly , ie to get it to the shop and not anything else

 

[deryans]

actually, it showed no codes - after the initial crank out of Pos, so hard to start diagnosing, we even thought it was the immobiliser , because she'd turn over and get compression, fuel good, battery good, but no catch ....... hard to work through

 

[karl2000]

Is it safe to assume that all these failing SCV's are the short ones?

 

[deryans]

I'd never assume as someone somewhere with a short SCV will pipe up and say different, but `I do understand that `roughtrax (and similar) suppliers only provide the longer one (denso) as of 2019 ? but after 150k for a "consumable" wear and tear item, not sure if it matters if its long or short: its preventative maintenance, wish `I'd known , I'd have swapped mine out at 120k - some 60 k ago

 

[karl2000]

Another (probable) SCV issue...

 

[Betoner]

Short one out,long one in... had some problems with falling a hex bit down under.
But job is done!

 

[karl2000]

had some problems with falling a hex bit down under.

ha ha you too.....


Well done!

 

[TonyP]

Easy job, but a arse to do. Well done

 

[Tractionman]

And me. Trapped on heavy aftermarket bash plates, and messing around on my back with a telescopic magnet.

 

[Iwan]

Eventually it threw a B2799 code and doing a bit of searching it's related to the immobiliser, and a thread on IH8MUD indicated that replacing the EFI fuse might help. I swapped it with the 20A from the seat heater, and tried again. Started on the button, and sounds and drives perfect.

As a new owner of a lc5 registered 30/11/2004.

I has an immobiliser fault occurring, it arrived with this and the truck hasn't been on the road since 2019/20. The truck has 94000 miles on the clock.

When it arrived last week the dash was partially dissembled to get to the ecu, so I resembled it to look into the immobiliser problem and it started straight up day before yesterday.

Yesterday morning the dash was like a xmas tree and doing the symptoms described in this thread. Turn the key fires then just turns over!

Left the batteries disconnected over last night and it fired straight up this morning and was able to move it. Turned it off and back to xmas tree dash and no start.

From reading @TonyP 's quote above and checking that it indeed has the short silver version SCV fitted. It's looking like a SCV fault does indeed activate the immobiliser.

Where do I find the EFI fuse and is it correct that removing the fuse cancels the faults on the ecu?

Also from the extensive service history upto 70 000 miles it states that the engine has 174bhp, is that correct for the age of the vehicle? With reference to euro ratings for ordering the new SCV.

Thanks in advance Iwan

 

[karl2000]

Does the engine actually start and then stop? From what I remember of the immobiliser on these, the engine will fire up and then it gets killed within a second or less.

Do you have an immobiliser light on the dash?

I'm not sure that the SCV is ithe first place I'd go to with an immobiliser fault. But it's worth changing the short one anyway.

have you got a check engine light? Have you got any current or stored codes?

Any idea of the history of the thing - eg ECU replaced?

The engine ECU and immobiliser ECU need to be in sync. If you change one or the other the two need to be syncd up. There's a procedure on here somewhere for doing that - might be worth a try. (From memory it involves shorting pins on the obd connector - if you can't find it here I'll check my notes, I had to do it once!)

 

[karl2000]

Btw these immobilisers are very sensitive to battery voltage, so make sure your batteries aren't at the lower end of acceptable voltage