Error Codes 22 + 33, High Idle and Running Rich

[roj]

Hi everyone.

I have a 1990 Elan SE Turbo with 99,600 miles on the clock and was acquired last summer. It had sat practically idle over the past 4-5 years covering only several hundred miles. After purchase, my wallet took quite a pounding getting her back up to spec with a new cambelt, full service, new set of tyres, etc, etc. She runs fine but on recently on start up she can be as high as 2500RPM and then after warming up will drop to 1250. I know they start on high idle when cold but after a recent trip to a specialist, it was noted that the idle speed needs to come down. It also smells rich when parking up in a garage after a run. Plenty of steam/vapour comes from the exhaust which is usual I guess on a cold morning. However, this afternoon for example after getting up to temperature, there's still vapour/water sat around the exhaust outlet.

I've trawled the forum to find an answer and have hunted for leaking vacuum pipes to start with. I thought I may have had a leaky pipe from the plenum to the MAP sensor (because of the error 33 code) and as I connected a hand pump to that line and applied the appropriate amount of pressure and with the car running, the idle came down to around 950rpm. That pipe was replaced but no joy. Maybe the MAP sensor? I've battled the passenger side inner wheel arch off and have checked the reservoir. The pipe that comes from the intake looked like it was just about hanging on and possibly kinked. Cut the kinked section out and reattached making sure it was well on the reservoir and was not kinking on the loop up to it. Still no joy.

I'm at a loss as to what to do next. Not keen on doing a throw money at new sensors all round treasure hunt. After a week of battling ElanScan and ending up buying the cheapest Win11 laptop available (useful for other stuff), I have finally been able to gather some data. Start up from cold to the point of the cooling fans kicking in. I then recorded a good 12 mile trip immediately afterwards with speeds up to 70mph and some hard accelerations giving the turbo some welly. I think the car runs fine apart from being rich and idling high.

With the error code 22, I whipped the air intake off the throttle body. Looks a bit dirty in there so plan is to get that off and give it a good clean.

Other item to note is that the injectors were taken out, sent off to be cleaned and checked along with the big service last year (summer).

I've also just recently changed the heating valve for a Volvo one as the internal heating was very poor. This has now improved although oddly, no water came out of the pipes when removing the old one. Coolant levels appear to be normal and have not dropped.

So enough of my waffle, see attached Elan Scan files and if any ES gods out there can have a shufty and give me any pointers then I would be very grateful. Many thanks in advance.

Cheers, Rog.

[chrism]

roj I'm NOT an expert but I can see that your EScan supports your code 22 and 33 diagnosis.

Do you reckon it's possible that both sensors have become 'duff' while it sat idle? They're electrical 'bits' that could suffer from moisture, bad contacts etc? I wonder if there's a way of checking them over with a multimeter? A simpler way would be substitution - but that'd involve buying new parts ...unless you had access to another m100.

I think I once read about the MAP sensor being unscrewed and cleaned - and isn't there a method of resetting the TPS by slowly pushing down and releasing the throttle a number of times with the ign on, then switching off for a minute or so, then leaving ign on for a minute or so? I think I'd try these. Another fix with sensors could be to disconnect the battery for a while, then reconnect in the hope that they'll reset. If your TPS and MAP still play dead I'd suspect they could be corroded by the relative lack of use...

Sorry I can't be more helpful, but perhaps one of our specialists might have some more useful suggestions.

[roj]

Forgot to mention the codes were recognised with the good old paper clip.

I’ll definitely be cleaning the throttle body. Is it possible to clean the throttle sensor? Those things are not cheap although I did read someone had sourced an alternative at a much cheaper price and only had to re-solder a couple of wires.

I’ll have another check of vacuum pipes and I think I may bite the bullet on a new MAP sensor unless anyone can shed any light on cleaning/recommissioning them.

Also forgot to mention the car has a PNM Parts/Peco sports exhaust with the extra silencer. Should that have any effect on the problems I am experiencing.

I’d also had a crack at disconnecting the battery to see if that reset anything. No change.

[Tuga2112]

I think the biggest clue you gave us is the fact that you have applied manually a vacuum to the system and your idol went down to a very good number.

That to me suggests you definitely still have a vacuum leak. you have to keep in mind that if the leak is somewhere else and you have applied negative pressure near the sensor the the leak is still present it's just that you made the sensor read the right amount but if you didn't apply that negative pressure in that line the leak would effectively increase the pressure all the way up to the sensor.

How long did you keep the pressure down for and did you actually notice the pressure going up as you were waiting for the engine to react I guess my question is did you leave it therefore a bit and see the pressure increasing even though we shouldn't?

Personally I would be considering changing all of the vacuum tubes first, just general tubing for that is not too expensive and since you already figured out one issue in one corner and considering the fact that they are now getting to 35 years old it won't do any harm swapping them all.

I'm suggesting this because I have also AI Idol but it's in my na and right now I have a few meters of vacuum tubing waiting to be fitted because it's cheaper to just swap them then it is to buy the tools required to fully diagnose a vacuum leak

[roj]

Agreed Tuga. I’ve ordered some pipes and will replace the whole lot and be done with it. At least that can be ticked off and narrow down fault finding.

[roj]

Bit of an update….

I’ve replaced all known vacuum pipes that can be seen. This includes the pain the @rse one that goes down the back to the secondary throttle valve (or what ever it’s called). Also include the pipe down to the vacuum reservoir in the passenger side wheel arch. Only pipes that haven’t been changed is the smaller pipe from the reservoir which makes its way back into the engine bay, across the bulkhead before disappearing through the bulkhead. The other pipe is the one that comes out of the bulkhead and into the heater valve (which has been changed for a new plastic Volvo type). Could those affect idle speed and running rich?????. If so, how the chuff do I go about changing them? Especially if the leak is behind the dash. So you know, I have the ability to swap between windscreen, blow vents, foot vents and change temperature so I assume we’re all good as there must be a vacuum.

So I bit the bullet and purchased a new MAP sensor and fitted it today. No change….However, my error code 33 has gone, like wise the error code 22. I did disconnect the battery before changing the sensor so the ECU will have reset. Went for a drive, no problems, got home, let her run up to the fans kicking in.

The other trick I have tried is the manual movement of the throttle valve 5 times with the ignition on, turn it off for 40 seconds, start the car. No change….

When cold she fires up at 2000rpm, once or twice has climbed to 2500rpm. Once driven and warmed up, she’s back down to around 1250rpm. You can hear the revs jump when changing gear sometimes as well (as clutch depressed).

When performing the old paperclip test and starting the car, she runs perfectly at around the 950-1000rpm. Could this be another sensor? I have a throttle position sensor on the way. Not a £300+ Lotus one but a £30 item from China. One of the other members on here flagged it and had success.I also plan to take the throttle body off and give it one hell of a clean.

I daren‘t adjust the idle speed valve yet until other avenues have been explored. Even if it brings the idle down, it doesn’t fix the running rich part.

So that’s where I am with this one.

Any help or suggestions gratefully received.

Cheers, Rog

[TorqueHorse]

Hey Roj,
Sorry you are still having idle issues.
I took a look at your original scan you posted. Not that I really know how to interpret these things (and my reference scans are from a closed loop system) but a few things stood out.
Your Manifold absolute pressure was indeed higher than mine.
Your actual idle speed was way higher than your target idle (so something is not behaving the way the system is expecting it to)
Your Idle Air Control valve values looked high. The max should be 80, but yours read at over 100 at one point. (Could just be out of calibration)

Your Coolant temps looked normal.
Your TPS voltages looked normal.

Things I would check next:
Run another ElanScan and see if your Manifold Pressure is down relative to what it was before (compare it at a similar RPM from your other scans).
Before starting your engine, but with the elanscan on and recording, slowly depress and release the accelerator pedal. You should be able to see the TPS voltage values change in real time via elanscan and you can compare against the expected voltages from the Engine Management Manual. (This can help eliminate if you actually need a new TPS sensor or not).
If you want to check if there is a leak in a vacuum hose, you can get little silicone nozzle caps. My hand vacuum pump came with a whole bunch. Just plug the nozzle at the intake manifold and see if there is a difference.
If you want to check if a stuck open IAC is contributing to your idle problems, the easiest way I found is to take off the big silicone hose going to the throttle intake. At the bottom of the now revealed throttle body housing lip is a hole that goes down to the IAC. Mash your thumb over it while your friend starts the car. Roll your thumb back just a bit so a little bit of air is getting in. If you are able to quickly get the car to idle well by manually rolling your thumb to find a sweet spot (compared to how long it takes with just the IAC trying) then that probably means your IAC valve has issues and it would be worth going deeper through the troubleshooting checklist on that item. (In case it isn't clear, you are using your thumb to recreate what the IAC's pintle is supposed to be doing by either opening up or closing off that flow of air).

The fact that you had those error codes though is making me wonder... It looks like an open or shorted to ground wire could also throw some of those errors. Regardless, if its not an easily found vacuum leak, then I'd really stick to the troubleshooting checklist for section EMK 6 under "...Incorrect Idle..." in theengine management pdf

[roj]

So........

The plot thickens! Otr should I say the cr*p I've discovered in pipework! First of all, big thanks to Torquehorse and your suggestions. Especially the stick your thumb over the hole in the throttle body. Soon as I did it, the revs immediately came down. I read more about the IAC valve and decided either way, it's gotta come out and might as well do it whilst I take the throttle body to clean it. After a good hour of wrestling with old pipes and their associated fittings, I was able to remove the throttle body. This also allowed much easier access to the IAC valve.

What I discovered was quite a shock. I'll let the pictures speak for themselves. This poor thing has been chocking itself to death. What on earth is going on with that pipe coming out of the throttle body? I haven't inspected it yet. Loooks like something has melted on the end of it. Hopefully cleaning those parts up this weekend. So a few questions to the group.

• IAC Valve - New one? Had look online, SJ are out of stock and it appears everyone else is too. Any alternatives? I see on the forum there are Vauxhall Astra ones but that also involves dismantling and rotating 180 degress or something. Not so keen on that but if needs must.

• IAC Valve - Cleaned up and maybe it'll function correctly again? Anyone with experience on that?

• Pipework - Obviously I'll be cleaning any cr*p out of pipes. Any handy hints on what to use or best way to do them. For the sake of it, would it be wise to replace the pipes?

• Still awaiting my cheap Chinese TPS sensor and will await its arrival. In the meantime, I'll check over the old one. Any pointers on anything to look for?

• Is this thing now going to run like a dog after cleaning it all up? I'm guessing it's been set up to overcome all blockage/dirt etc rather than fix the problem itself.

* Any thoughts on how it could have got so bad? A simple blockage has made it run rich and because it's been left so long the junk has just accumlated?

Apologies for all of the questions as this is certainly a learning curve for me. Thanks for help and guidance. Really appreciate it.

[dapinky]

First, my experience is slightly different to yours, in so much as the throttle body was a bit grubby, but nowhere near as grim as yours....

I started off with an aerosol of 'Carb Cleaner' but it didn't last long (it wasn't full when I started) to get the worst off, then read the contents of the can and decided that liquid Naptha would do the same job..... so I went to the shelf and grabbed a 5L can of Fast panel wipe (which is 98% naptha) - do not use the Slow wipe - it isn't naptha (but may well still do the job for what we need here).

I then stuck the whole item into a bowl of naptha and left it to soak for a while...... and when it cam out it didn't need a lot of work to look brand new - being a bit lazy, I finished it off with clean naptha in a spray gun to simply wash away the crud and rubbish - if you just leave it out in the air, the liquid will evaporate and leave the carbon behind.

Obviously, I removed as much as possible first without stripping it right down, and blew it all out with compressed air afterwards to ensure the passageways were clear.

I cleaned up the IAC valve at the same time - but if I were doing it now, I'd use the 'aftermarket' GM version and adapt it to fit.

[roj]

Anyone got a link to the retro fit of a GM IAC valve?. I saw a post on here with one stripped down but can’t find the post/thread. Doh!

[Tuga2112]

my M100 throtle body has never been that crummy.
but my 4Runner was. and it was the reason why my iddle was too slow at one point in time..,

as far as the crummyness i personally wouldnt worry much about it at least for now.

IAC valves.
i have done the swap you mention. and i ended up rotating it 180 degress around to install as well as enlarging th holes in order for things to eventually fit... its been just fine 3-4 years now. I Have a spare on the shelf. but i suspect you will find a replacement easy enough on ebay. i think mine was 12 each, (reason why i got a spare)

i took this picture while trying to install it which will give you an idea why when you turn it 180 degrees it needs adjustment.
the bolt is already threaded in. and the valve is seated. but the secon hole doesnt align. so you will need to enlarge them both to be able to rotate it a little to fit

[roj]

I managed to find the post on alternative IAC valve.

https://forum.lotuselancentral.com/viewtopic.php?f=46&t=16687&hilit=Idle+air+control+valve+gum&start=20

So for the sake of £12, I’ll give it a shot. Currently no other option.

We shall see next week. Tomorrow is throttle body cleaning day!

[roj]

Forgot to ask. Whilst cleaning out all associated pipes with the throttle body. I removed some pipes from the oil separator box. Is this something that needs cleaning / maintenance/filter inside changing? Or is it a leave it alone kind of thing.

[Tuga2112]

never touched mine. its probably going to reach 140k next month. but i wouldnt stop you if you really want to go there.

[roj]

A can of carburettor cleaner later and we have promising results. By no means finished.

You'll see that the one pipe outlet has disintegrated. Part of it was folded over and therefore created the blockage and got worse over time. I guess this might be a case of chop the cruddy end off as far as possible. Just had a quick look at the parts list and doesn't appear to be a separate item. Unless anyone knows any different. If there are replacements out there (please let me know), but how do you get it out and equally, how would you get the new one in???

Also had a quick bash on the IAC valve. I have a GM part on the way, just interested to see how well it would come up.

[dapinky]

The water pipe is a zinc-plated steel tube, which is press-fitted into the aluminium casing. Now, what adhesive, if any, that is used would be a pure guess.

If it were me, I'd remove the whole steel tube that remains by mechanical means (pulling, grinding, drilling or whatever works), then clean the hole up and replace the tube with a stainless steel or alumin(i)um item..... I haven't looked, but would expect to find a suitable hose joiner in the right sort of diameter - something like this??

I'd be fitting it (cut-down if needed) with a 'chemical metal' (JB Weld or similar) adhesive/filler.

[Tuga2112]

If it were me, I'd remove the whole steel tube that remains by mechanical means (pulling, grinding, drilling or whatever works), then clean the hole up and replace the tube with a stainless steel or alumin(i)um item..... I haven't looked, but would expect to find a suitable hose joiner in the right sort of diameter - something like this??

I'd be fitting it (cut-down if needed) with a 'chemical metal' (JB Weld or similar) adhesive/filler.

I Would consider getting a new tube with a threaded end, and the possibility of tapping into the metal. replacing the whole section with new. PTFE tape should be enough to seal it

im not suggesting my idea to be better. just what came to mind when i saw the pictures.

[roj]

Sorry for the questions but one last thing observation on the throttle body. On the pic attached, you will see where I have highlighted where one of the pipes connects. Inside this pipe looks to be an insert. I assume its an insert as it has a perfect hole in the middle and is hopefully not more cr*p build up in that pipe. The other pipe seems clear. That's not to say that pipe is missing an insert. Anyone have a throttle body to hand to look at and check. Thanks in advance.

[TorqueHorse]

Yes, that is a factory restriction on that vacuum hose take off. Looks as it should

[roj]

Thanks for confirmation TorqueHorse.