Help! Engine Management Light 5th Gen VTI

Post by **Doggo** » Tue Feb 12, 2013 2:24 pm

Engine Management Light -1999 2.2VTI Motegi H22a8

Hoping someone can help here. Sorry this is a bit long. I don't mind admitting I'm clueless when it comes to car mechanics :-/

OK, so I bought a Prelude with an engine management light on. Yes, I know. For financial reasons it's going to be a few weeks before I can do anything with it and it's in storage uninsured (Can't be driven around) until my company car is returned in a couple of months for when it needs to be fixed. I don't have any jacks or stands at present, but have some basic tools.

The car will go in for its cambelt in a few weeks but from what I've heard the local Honda garage otherwise might not be much good for diagnostics...

SYMPTOMS:
A bit sketchy as I've only had one journey home in it and was babying it due to light on and cambelt.

Engine management light comes on when driven a little while – seems to be more from accelerating than just at random. Definitely comes on when revs go up to anything reasonable (maybe 3.5k+?). Light goes off when ignition turned off. Drove many miles on motorway with light off by keeping revs low/gentle throttle – then booted it in third (Couldn't help myself), but light came back on and revs dropped out before redline.

On arriving home found oil level a little high.

Did paperclip test and got code 2 long 1 short, which I believe is VTEC Solenoid (or solenoid valve or something)

Also, revs seem to drop very low (Almost to stall) briefly when you get off the throttle. Otherwise idles at maybe 800 rpm(?) which I guess is OK(?).

Car has full dealer history and 44k on clock but never had Cambelt done. Probably stood for a bit before I had it.

I was thinking:
Might be oil level, but probably not as not that high, plus why revs drop so low?
Might be O2 sensor (Revs drop) but would that explain the VTEC solenoid light?
Might be cambelt related, but I'm replacing due to age and as far as I know there's no problem?
Might be VTEC solenoid, but would that explain the revs thing? Plus the light comes on way before VTEC engagement
Could be idle sensor (Idle problem)?
Could be other exhaust related? Or Cat. related? (Doesn't sound like any leaks but otherwise unchecked)

One more thing – it had a new clutch before I got it. Not sure if something might have got knocked in the process?

Saw this thread, which seems to suggest that maybe the idle thing is unconnected with everything else and maybe the least of my problems?
http://www.ludegeneration.co.uk/honda-p ... 18-10.html

Any suggestions about what (simple) I might try at home (And what first) before crying like a girl to the local Honda Garage? (Alternatively, anyone know any very good clued up garages in Scotland?)

Any help appreciated! Not asking for anything comprehensive it's just that you guys probably have a better feel for what's more likely to be the case.

Cheers,

Doggo

Post by **Donald** » Tue Feb 12, 2013 2:36 pm

Can't really help you other than ~800 rpm idle is normal.

Post by **Merlin** » Tue Feb 12, 2013 2:52 pm

Yeah a code 21 is for the VTEC solenoid, which also ties in with you not getting VTEC. It could be gunked up which requires a clean. Have a look at the 5G service manual http://prelude.openbarr.com/manuals/5th_gen/ page 122. I take it you could only get to 6.5K before you couldn't rev any higher?

If I were you I would disconnect the battery for a couple of minutes, this will clear all stored codes from the ECU. Then, if the engine management light comes back on, it will be easy to diagnose as only the codes that are effecting you now will show.

As for revs dropping, do you know if you have any holes in the exhaust? Specifically before the O2 sensor? Like in the flexi pipe?

mercutio · Post by **mercutio** » Tue Feb 12, 2013 3:21 pm

as already said clear the codes, check again, clean vtec solenoid

Post by **Doggo** » Tue Feb 12, 2013 3:27 pm

Donald wrote:Can't really help you other than ~800 rpm idle is normal.

It all helps, cheers!

Post by **Doggo** » Tue Feb 12, 2013 3:47 pm

Merlin wrote:Yeah a code 21 is for the VTEC solenoid, which also ties in with you not getting VTEC. It could be gunked up which requires a clean. Have a look at the 5G service manual http://prelude.openbarr.com/manuals/5th_gen/ page 122. I take it you could only get to 6.5K before you couldn't rev any higher?

If I were you I would disconnect the battery for a couple of minutes, this will clear all stored codes from the ECU. Then, if the engine management light comes back on, it will be easy to diagnose as only the codes that are effecting you now will show.

As for revs dropping, do you know if you have any holes in the exhaust? Specifically before the O2 sensor? Like in the flexi pipe?

Merlin,

I did try disconnecting the battery for a while (Also using brake pedal to remove any residual current) and this is the code that was left.

Honestly couldn't tell you what revs I hit. Really I ought to drive it again for more info. - just uninsured until end of month and paranoid about causing any damage! (I guess on reflection the engine is protecting itself).

Thanks for the Manual link - looks excellent, and sounds like I now have a plan:

1. Buy Multimeter!
2. Test Solenoid
3. Clean solenoid, or replace solenoid/gasket/seal as thought required
4. Get on ramp and check exhaust carefully
5. Test(?) or Swap O2 sensor if no holes?
6. Cambelt!

More to the point, your and Merc's comments make me think that the solenoid is actually a good place to start (Which I wasn't at all confident about despite the code!). If it's not the solenoid then I'll think again.

I'm getting feeling that no-one else is trying to connect everything together into one problem so this seems to make sense.

Thanks!

Post by **Doggo** » Tue Feb 12, 2013 3:50 pm

mercutio wrote:as already said clear the codes, check again, clean vtec solenoid

Merc,

Thanks. Good to see some accord on a good place to start!

I'm lucky to have other transport, but it's driving me nuts not being able to drive it!

Post by **Merlin** » Tue Feb 12, 2013 4:35 pm

Multi-meters are a good idea, and really cheap (I didnt realise how cheap untill I looked). The problem with the VTEC solenoid is that they get gunged up so hopefully you dont need to replace anything.

Dont worry about what revs you were able to hit, I was just asking if you noticed. 6.5K is the limit you can go if VTEC does not engage.

Post by **Doggo** » Tue Feb 12, 2013 4:53 pm

Merlin wrote:Multi-meters are a good idea, and really cheap (I didnt realise how cheap untill I looked). The problem with the VTEC solenoid is that they get gunged up so hopefully you dont need to replace anything.

Dont worry about what revs you were able to hit, I was just asking if you noticed. 6.5K is the limit you can go if VTEC does not engage.

Indeed. Fancied a nice Fluke one but that'll have to wait.... just ordering a new cheapy off ebay for £13 delivered!

If anything I thought I'd revved a little higher, but this seems a good place to start regardless. If I remove the solenoid to clean around do I have to replace the gaskets/seal even if apparently OK? Not a problem - I'd rather do stuff properly - just not sure.

Edited to say what I actually meant.

Post by **Merlin** » Tue Feb 12, 2013 5:04 pm

Personally I'd only replace if they look distressed or broken, or if you have an oil leak from there. Although the service manual does say to replace it. It wouldnt cost more than a couple of quid to replace.