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VTEC not kicking in on Honda Elise (Hondata)

Maxx

Maxx

Messages
24
Hi,

First post here, sorry to kick off with a question but am struggling at the moment.

I have a Honda Engined S2 Elise. It's one of the early ones (No 12 from Maidstone Sports cars). It uses the HONDATA piggy back ECU, the ECU has not been pumbed into the OBD2 socket.

Cars been fine for 2 years or so but recenrly the VTEC has stopped kicking in. I was on a trackday and MSC were there so they swapped out the cam sensors, as this is one potential cause, no joy.

They advised an oil change, done and still no joy. Also disconnected the battery for 30mins to clear any possible ECU issues.

The car revs fine, right to 8k. The VTEC is programmed to kick in at 4,500 adn there is normally a definite pitch change and surge. I get a very slight pitch change but no surge.

I cant easilly run it round to MSC as i'm 170miles away in Nottingham.

Anyone any ideas?

Does anyone on here know a place nearer to Nottingham that can help? i.e. they would need to be able to read the HONDATA I assume).

Many Thanks

Malcolm
 
Lee,

Wow, thanks for the swift reply. Now, I should have explained, I am to engines what Kimmi Raikonnen is to public speaking :)

I do have a local mechanic I use for most things though. Could you just expand a teenzy weenzy bit on your post, where is the solenoid located?, any way to test? or is it a relatively cheap part we could just replace and see?

Many Thanks

Maxx
 
Lee,

Thanks. I've since done a search and have a pretty good idea where it is and have an idea of how to test it.

Ta
 
I can remember a chap on CTRO had the same problem, free reving, healthy engine, just no vtec.

Turned out to be the solenoid after I mentioned it to him.

Best of luck Maxx.

Keep us posted.
 
Thanks for all the help and suggestions guys. Just spoke to my mechnic guy, he thinks he knows where the solenoid is, it looks to me like it's on the engine block, just next to the oil pressure and oil temp sensors, near the exhaust manifold, is that about right?

Someone mentioned you can connect a live feed to it and see if it clicks but didn't expand on it i.e. how to. Guess my mechanic should know this.

Apologies for just signing up and launching straight into a question without saying Hi first. I'll have a look rond when I have a moment and see if I can contribute ... clearly this will not be on the mechanical side :) but if you want to drive em quicker then i'm your man.

Malcolm (Edeson)
<2007 Britcar 24Hr Champion, Honda Civic Type R>
 
Maxx said:
Thanks for all the help and suggestions guys. Just spoke to my mechnic guy, he thinks he knows where the solenoid is, it looks to me like it's on the engine block, just next to the oil pressure and oil temp sensors, near the exhaust manifold, is that about right?
Click to expand...

Sounds about right Max as the VTEC is only engaged once oil pressure & coolant temp is up.

Your mechanic will defo know how to wire a live up to it & you'll hear an audible click almost like a relay switching to know it is that. They can stick so it might just need freeing up.
 
OK, just dropped off gthe car with my mechanic, he did mention one thing, which might be significant.

There is some sort of "sensor" in the middle of the large water hose. I did take a picture but it didn't come out, so I will attempt to describe.

So, looking at the engine from the rear (of the elise, exhaust manifold is nearest me, gearbox on left), on the left hand side, well down, near the bulkhead there is a thick (2") pipe. The pipe is split into two halves and there is like a collar round it and on this collar is a metallic square "thing" with what looks like epoxy resin in it. There is an electrical wire to it.

He metioned that on the last service it looked quite corroded and he cleaned it up. I imagine it's some sort of water temp sensor?

Could this be the problem if it was faulty? Is it this that provides the ECU with engine temp?

Is it a standard Honda part?

TIA

Malcolm
 
Defo could be the culprit tbh Maxx.
i-VTEC change over is governed by oil pressure being adequate & coolant to up to temp before it will allow cam change over. So if the coolant temp sensor is scuppered it wouldn't allow the change over which makes sense.
 
No joy today i'm afraid. My guy didn't get a lot of time to look at it, was just trying to fit it in and had an unexpected breakdown call to deal with as well.

Couldn't actually get the solenoid off (the one in the cage near the exhaust manifold). Could get one bolt off but the other is really close to the block and the rear bulkhead of the Elise, his socket was on a reducer and just couldn't get purchase. We did connect a live feed and it did "click" but it was a click more than a clunk, which is what I was expecting. Not much more than a loud click tick.

All the cables look good and he cleaned the contacts up and sprayed with wd40.

We also "found" what looked like another solenoid on the end of the engine block (opposite side to the gearbox). Very hard to get at in the Elise, could only see it with a mirror). Looked a bit rusty actually but connectors looked fine.

I do now have a contact in Leicester who knows the conversion well, has all the gear and can definitely sort it so will go that route.

I am still curious though ..

Does my description of the solenoid "tick" sounds about right?
What is the other thing I describe on the end of the engine block?

Maxx
 
very unusual it does sound like a solenoid problem, my friend was working on a dc2 and took it for a drive and had no vtec, looked about the engine bay and found the vtec solenoid was unplugged and the problem was rectified when he plugged this back in.
 
SORTED


Took it over to Simon Scuffham, the main man behind the original Elise/Honda conversions. He plugged his electronic wizardry in and we went for a spin. At first it was a bit of a mystery. The VTEC "was" kicking in and all looked as it should, just then Simon said "OK, turn around, I know what it is".

Sure enough he pulled the air-filter apart and was presented with perhaps the filthiest air-filter he had ever seen. What he'd seen on the laptop was an air-flow measurement that should have been nearer 70 was in fact 40 at best which led him to this discovery.

The air filter looked like it had not been touched for 2 years (basically the length of my ownership). It doesn't do a lot of miles usually but I had used it on the road a lot during the winter. It's had numerous oil-changes but only 2 services during that time and both coutersy of my sons mechanic (he runs a 2nd hand care company) so no bill to check.

He is a decent mechanic but obviouosly no exposure to elise/honda conversions, the air-filter is a Hurricane. It may be that he did clean the air filter on the first service but definitely not on the last one. The Air filter is actually fed via one of the scoops on the side of the Elise so does pick up lots of road grime.

Anyway, sorted and lesson learnt.

Malcolm
 
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