Lotus Elan Central

I should start by saying I bought a car from the cheaper end of the market.

That said, I have a habit of doing that and turning them into something better, always with an emphasis on originality wherever it remains sensible to stay at original spec. The plan for this car is initially to get to the bottom of it's running fault(s) and then work on cosmetics before I go into any kind of upgrade mode.

The job list grows a bit every time I look at the car, but for the moment the priorities are:

1) Pass the MOT
2) Buy and fit a decent alarm / immobiliser
3) Drive it for the rest of the summer
4) Replace the cambelt kit and water pump (more for peace of mind)
5) Give it a service, replace oil, brake fluid and coolant.

The other thing I should say up front is that I'm up for the challenge of doing all of whatever work is needed by myself, at home and so I always appreciate shared experience from others - my trail of Vauxhall ownership has led me to buy the dealer level diagnostic kit (Tech1 and Tech2) and I've not been dependent on the motor trade (apart from parts) for a least the last 10 years, probably more. A problem that leads me to buy more tools is more fun...

A photo of the beast...

So, part one - it appears to be running very very rich and I have started to work through diagnosis, but need to take stock and do it properly.

Starting with the problem - it takes an age of cranking (5+ seconds) to start, when it does, it runs on only one or two cylinders for a short while it emits a bit of black fuel-laden smoke from the exhaust. My first thoughts were low compression, or perhaps leaking injectors, as it occasionally starts properly when left to go cold. On the road it seems to drive pretty well, smoothly at least. Starting is awful, reliably, from cold or hot. Occasionally, in either state, it might start normally, but that would be on less than 1 in 20 tries.

I've checked
Compression - 185PSI on all cylinders
Battery Volts - it doesn't appear to dip below 10V on cranking
Alarm - previous alarm is now on the garage floor (siren was faulty)...
Spark plugs - 1,2 and 4 quite fouled with black soot, 3 much less so. Fouling reduces with longer drives and looks browner. Cleaned up, gaps checked and correct at 0.8mm
Injectors for leakage - Superficially checked I suppose - for the compression test, I ran the engine until hot, switched off and pulled fuse 5 to disable the ECU and prevent it running the fuel pump / ignition. With plugs removed, no fuel smells from the bores / exhaust. So I don't think they are leaking. I don't have a fuel pressure gauge to carry out an injector balance test.
Coolant Temperature sensor - works correctly and is read correctly by the ECU


Then, in the quest for data, Geoff helped me out hugely by supplying an ALDL interface so I could use Elanscan to look at what the ECU thinks is happening.

I have taken a couple of logs, the first is a 'warmup' log that confirms that (as I suspected) my thermostat is goosed. I can't actually see anything else wrong from the data but I am hoping that you guys (and girls) will spot something and let me know what I missed.

The second log is driving it a few miles to my local MOT garage, where I used their gas tester to see what was what. The journey was all normal (slow) driving in 30-60 limits.

And here was the result of the test at tickover - photo below.


My understanding of this is that it corroborates my theory about it running too rich - low Lambda reading, high HC and high CO. That was with the engine hot, after revving it a bit to clear initial start up fuel in the exhaust.

I will host and link the Elanscan runs in case anyone fancies a challenge. At the end of the 'warmup' one, there are two start events - I simply switched off the engine and re-started to capture the conditions in the log. Unfortunately I was a bit remiss with logging from cold and missed the first couple of minutes, but the MAT and CTS values did agree before I took the car out of the garage.

Comments (and suggestions) very much appreciated.

Ian.

Log data here:

Warmup phase to fans cycling:
http://abs-zero.com/lotus/20140723_first_warmup.ecu

A few miles drive at low speeds:
http://abs-zero.com/lotus/20140723_local_drive.ecu

Spark plug comparisons:
Plug 3:
Others:
That would suggest pot 3 is running leaner than the others, which might point towards a leaking inlet manifold gasket, but idle revs are fine and IAC appears to be sensible.

Ian.

I had a chance to look at the car again today and have a couple of theories, which I'd appreciate some review of.

Yesterday, I cleaned up the earth to the ignition coil amplifier - mainly because it was screwed into a slightly dusty looking aluminium sheet. Tried cranking over, it was clear this hadn't changed anything, so I pulled the plugs out. They were wet with petrol, so I used a small blow lamp to burn that off and used a torch to look at the piston crowns, obviously they looked wet and a little sooty, particularly in pots 1 and 2. So I left it all open overnight to evaporate and this morning pulled fuse 5 (ECU) and cranked the engine over a few turns, before looking back at the piston crowns. Slight wetness in a couple of pots on the inlet side.

So, I'm considering leaking injectors again, which was my initial hunch.

Last night, I searched some more and found the correct setting for the idle bleed screw in the WIKI under 'tickover', which suggested that it should be 1.5 turns out from fully-in. Checked mine this morning and it was only just over half a turn, so, despite not putting the car back into service mode and adjusting the idle properly, I reset it as per other people's examples and drove it to a friend's garage in Croydon.

For fun I fitted a new set of plugs (NGK ones as per the WIKI) and drove the car the short way to Croydon, where I had the job of repairing a customer's Corsa D. (Note to self: these things are better got at first, rather than 4th hand, as there's 3 other people's diagnoses and fault repair attempts to re-diagnose and reject).

Anyway, back to my car. After fixing the Corsa (the Elan engine had cooled) I pulled the plugs out and inspected them. As before, no3 was quite white, the others were a medium browny colour, slightly black around the sides of the insulator. Again there was wetness on the piston tops, this time on pots 1 and 2 particularly.

I then spent well over an hour chuntering at my inability to fit a hose to the fuel rail input connection on the back of the inlet manifold. My reasoning was that I could measure the fuel pressure at idle and during a big blip of the throttle (or better, using a mityvac to actuate the fuel pressure regulator to confirm the pressure increases in non-idle conditions. I can't find anywhere a spec for what the fuel pressure should be though, so it was just going to be a 'I got x bar on my fuel rail, what should it be?' question on here tonight. Alas I chuntered on for a while and still couldn't fit the inline pipe and had to give up for the day. Good news though, I have borrowed the test kit and will have another go, probably after removing the rail.

Driving the car today was less pleasurable really, mainly because the engine 'felt wrong' and very occasionally misfired into the exhaust as it left idle. It's very wrong, I've done 135 miles on an indicated 3/4 tank of fuel, so I could have run a Veyron for the fuel consumption I have managed so far . I won't drive it anywhere now until I have what looks to be a proper fix, as I don't want it to end up bore washed. Apart from anything else I am sick of the smell of unburned petrol!

On the way home I stopped off and connected up my Elanscan interface and logged the rest of my return journey, then left the engine to run until the cooling fans had cycled before switching off. I will attach the logged data in a mo, but the first thing I'd note is that the IAC is set solidly at 3 steps for the whole of the time it was idling and it couldn't (quite) get to the desired idle of 950, settling at 975 instead.

So I am also considering that there is an air leak somewhere. What I can't tell is whether it is in the inlet manifold (favouring cylinder 3 to make it run leaner than the others) or elsewhere, but I have been round replacing vacuum hoses and will continue doing so until I have got every last pesky one.

What's the community wisdom here, a combination of two faults, or something else?

Cheers,

Ian.

Some more observations from the scan data:

On the move, the engine coolant temperature drops to 75 degrees, reinforcing the knak'd stat diagnosis. That will make it run slightly richer I guess.

MAT quickly goes up to just under 70 degrees when the car is idling and doesn't remain in the 20 to 60 degree range expected. No idea of impact on mixture.

MAP struggles to get close to the desired range, sits solidly at 0.43 (not in the 0.3-0.4 range), probably due to the wrongly set idle / air leak / fault.

Course of action - comments appreciated:
1) I think my next job should be to remove the fuel rail (can it be done with the inlet manifold in situ?) and check to see if any injectors are dripping when the fuel rail is pressurised. I can't easily fire the injectors for a known time accurately enough into a test tube, so I can't test flow rates, nor do I have a pulse generator to fire them and check for pressure drop (to check injection quantity balance).
2) Find, check and replace remaining vacuum lines to ensure no unwanted leaks.
3) If the injectors seem OK, I think I need to have the inlet manifold off to check them for cracks, the gaskets for leaks and give it all a good clean out and overhaul.

The next bit of information I will be looking for is injector models, specification (of standard items) and a source of gaskets, seal rings etc.

I've just found a comprehensive set of manuals online, so will have to spend some quality time to get to know them, which might answer some questions.

Ian.

Today's log file can be found here:

http://www.abs-zero.com/lotus/20140726_ ... d_idle.ecu

Despite having no idea what you are talking about whatsoever my only thought, until someone more technical comes along, is that you should do (2) first - always take the low hanging fruit!

epipete wrote:Despite having no idea what you are talking about whatsoever my only thought, until someone more technical comes along, is that you should do (2) first - always take the low hanging fruit!

Agree about he low hanging fruit. I've already replaced the ones to the EGR control solenoid and the one to the fuel pressure regulator, the others appear to be (not exclusively) to control heater components and (I expect) boost. I just wasn't expecting to see petrol on the tops of the cylinders or wet plugs on every cranking event so had to assume that implied a problem with the injectors themselves.

Cheers, Ian.

Hi Ian & welcome to the forum. It sounds like you've got the right mindset for Lotus ownership
Once up & running, the Elan is not usually a handful to keep running.

I have checked your warm-up log & can see some things which you may want to investigate. I can see you let the engine idle until around 960 seconds. I agree that your stat should appears to not be controlling your engine temp.

You appeared to engage 1st gear, reaching 12mph, then 5th, reaching 6mph , then 1st again to reach 2.5mph.
Your engine speed reached 6500rpm although you applied zero throttle.
Your battery voltage dropped off completely.

rip wrote:Hi Ian & welcome to the forum. It sounds like you've got the right mindset for Lotus ownership
Once up & running, the Elan is not usually a handful to keep running.

I have checked your warm-up log & can see some things which you may want to investigate. I can see you let the engine idle until around 960 seconds. I agree that your stat should appears to not be controlling your engine temp.

You appeared to engage 1st gear, reaching 12mph, then 5th, reaching 6mph , then 1st again to reach 2.5mph.
Your engine speed reached 6500rpm although you applied zero throttle.
Your battery voltage dropped off completely.

Thanks Rip, I'm hoping I have some simple faults that previous owners just couldn't find and I can put them right and end up with a good car.

As for the interesting readings, the car didn't go anywhere on the warmup log, I'm not sure if there was either data corruption, or the speed sensor is noisy in some conditions (stopping in a transition between 0 and 1 and therefore appearing to intermittently oscillate at the ECU input). Note that there are two (or was it 3) startup events included at the end of the warmup log - what I did was run the engine until the fans had cycled and then switch it off for a few seconds before attempting to restart it, repeated twice. The aim was to show what the ECU was doing during cranking that was obviously not having the desired effect. Perhaps that caused the odd readings, as it could quite possibly have upset the ALDL feed if the ECU suspends data output (part full serial buffer) and then starts anew when cranking starts next time, leaving the buffer full of mixed old and new data that gets wrongly interested by ElanScan. It seemed to happen to some readings more than others, so I feel I am clutching at straws.

I have been looking up injectors and conclude that ours are possibly of the Rochester type, which might mean they have the ball type nozzle and are reportedly prone to gunk up with varnish deposits. I suppose if they began to gunk up they might also fail to close correctly.

So cleaning might be the answer, otherwise a new set. Trying to manage my expectations and looking at the Fuel Injectors page on the wiki, a set is identified from RC in the states that has a flow rate of 320cc/ min at a specified 43.5PSI, which equates to 3 bar. They are also 'peak and hold' types (low resistance), which I think might differ from many (the majority?) other cars. If that is a correct spec, then I should now be able to test my fuel rail pressure and once I have removed it, that will be my next step. Those injectors weigh in at about £353 if my calculations of exchange rates, postage, import duty and vat are roughly correct, so not the end of the world.

I have partly disassembled it and got it to the point where all I need to do now is disconnect the fuel input and remove the fuel pressure regulator and then I should be able to get both the fuel injectors and rail out, all being well. I hope. Given there is potential for the areas immediately around the injector bores to be dirty and therefore make refitting a risky job, perhaps I would be best to remove the plenum and manifold and take the opportunity to clean both up properly before putting it all back together. I had to stop this evening because I didn't want to disconnect the rail and (inevitably) spill some fuel just before closing the garage up for the night and leaving a stinking (and not to mention potentially explosive) atmosphere.

I was wondering if there was an identically sized Bosch injector, as there is a good chance of finding a set over here and they appear to be very reliable, even second hand. There will be a slight difference in spray pattern between a Bosch disc and a Rochester ball, but if the flow rates are correct the difference should in effect be pretty marginal. I did find on eBay a set of injectors from a 1.6 Corsa that will have the wrong flow rate, but were obviously the same physical design as ours. I have the offer of the loan of a set from An Esprit turbo (uses the same management as Elan) but unless I can confirm the spec is the same (which I really doubt) that idea is a non starter and I don't want to take silly risks.

The challenge will be to find someone trustworthy to test my injectors and either clean or recondition them (or buy new ones).

I will post some photos when it is in bits. If the test works, then I might be able to get some video too.

Ian.

Hi Ian,

I believe some on here have fitted these from RockAuto. Not much more info on the site, but the parts cross reference might be useful.

Also these are a lot less than the RC injectors, which I thought people fitted if they needed more fuelling due to other mods (larger turbo for instance). However, usual caveats apply as I have neither fitted these myself or the RCs. Someone wiser will no doubt pipe up....

As an aside, but of interest to me is, once you have the rail off, could you kindly take some snaps of the fuel regulator and how it fits - thank you

From Rock Auto:

Isuzu, 1991, Impulse, IMPULSE 1.6L L4 Turbocharged : Fuel/Air : Fuel Injector
ULTRAPOWER Part # MFI559 New Premium Quality New Multi Port Injector; 4 WHEEL/ALL WHEEL DRIVE -- $33.79 Each
These are EOL (End of Life) NOS TRW OEM parts.

Also on eBay US:

Set of Four BRAND NEW Delphi Fuel Injectors, 1991-92 Isuzu Impulse & Lotus Elan:
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... =mtr&item=201131507741#ht_3370wt_1125 --- $159.00 for the set

The eBay items are EOL, NOS from Delphi, NOS and come with the retaining clips. The Rock Auto injectors don't come with the clips.

When these are gone, I don't expect to see anyone else offering OEM injectors (and at a great price).

Of course, you will need to add shipping, Duty and VAT to the price.

Maz_r, thanks, I wasn't totally confident that the RC ones were correct, but found this 'spotter's guide, which i think would be useful to other people: http://www.robietherobot.com/storm/fuel ... rguide.htm. Good also to know that you have bought a set and they were good, plus correct for standard fitment - i wont have any need for upgrade bits.

John, it says 'God' against your name as well, and I can see why - thank you. . I have emailed the eBay seller as they don't post to the UK and I guess will have to consider it. I expect postage will be about $80 based on RC's price for shipping. Your post helps a lot because these parts don't show up in my eBay searches it seems simply because postage is not offered to here. In the UK, Delphi is well known for all sorts of parts and TRW make the power steering pumps for newer Vauxhalls, but I have never seen injectors from them. If you are pretty confident of the Rock Auto ones too, I will give them a shot, particularly if the Delphi ones aren't available.

Great prices though, on both - I was battening down the hatches to pay double that and am almost inclined to fit new anyway, but have never owned an engine that has had a faulty injector in over 20 years (the majority of the cars have been over 10 years old and i have had quite a few of them).

Hopefully this evening I will have chance to pull them out and all being well will find a way to test them at home. Will update later.

Thanks very much for both replies, they are really appreciated.

Ian.

Ian,

If it helps: I recently installed the injectors from Rockauto as well. The look identical to the OEM ones (of the S2 at least)
Fitment is perfect (as per above) and they run beautiful

Oh, more info here:
viewtopic.php?f=37&t=23179&p=294867&hilit=injector#p294867

Ian: If the eBay seller won't ship to the UK, you could get someone in the US to receive the FREE shipment (you buy eBay and pay for them but use a US address to receive it) and they could post them on to you for around $35.00 by USPS Priority Mail. email (don't PM) me if I can help.

Both injector supplies are OEM and correct for the Turbo M100.

Thank you both, really helpful. I nearly went straight ahead with an order of some kind but kept my powder dry until I had it all to bits, so I'll attempt to describe what I have done and then let a few photos do the talking. I have succeeded in getting the injectors out and the rail, then plumbed in a pressure test kit inline with the high pressure feed from the pump so that I can pressurise the rail and verify that (a) the injectors don't (do) leak and (b) that the fuel pressure regulator operates correctly.

It was a fiddly job to say the least, but nothing got bent or broken so I'm happy with it. The rail and injectors were moderately dirty really with no previous attempt to clean either up, so once out, I used carb cleaner and a paint brush to get rid of the worst of the muck and make them clean to handle, but more critically, to prevent introducing any of the disturbed dirt into the rail or injectors. Needn't have bothered I guess.

Conclusion is that injectors 1 and 3 leak well enough to be blowing bubbles out (with fuel). The other two appeared to remain dry for the first 30 minutes of observation (I periodically primed the pump by switching the ignition on). When disassembling the rail there was no residual pressure. I'm going to conclude they are probably goosed as there were traces of rust on the necks inside the rail as though there had at some point been a small amount of water in the fuel, so I shall definitely replace them and it looks like my lawn mower has just won a couple of gallons of fuel as I will also empty the tank before fitting the new ones.

The fuel pressure regulator appears to work OK, holding 3 bar while the pump is running and dropping to approx. 2.4 bar if I suck with my mouth on a small bore tube pushed on to its nipple. Oooo-er. On that basis, provided that drop is what it should be (no specs found yet) the FPR passes my non-scientific test, since the vacuum connection is to reduce fuel pressure at idle (wonder if it raises it on boost also?).

I think my plan is now to remove the inlet tract and manifold and clean it all up as it will be difficult to clean up the injector bores well enough and put the rail back - I will need gaskets, and as a non-expert on M100 parts will trawl the search to work out where the best place to get them is, otherwise the default might just be to put an order together to RockAuto for:

4 injectors
Water pump and gasket
Cambelt kit
Correct thermostat and gasket
Inlet manifold-to head gasket
Inlet manifold-to-plenum gasket
Heater resistor?

Guess that would make the postage worthwhile. Does anyone else need anything?

Photos in a moment when I have resized them, but enjoy this youtube clip that shows an injector leaking. https://www.youtube.com/watch?v=JPMOZr3 ... BXNi1nnIDQ

Conclusive enough? It's pretty slow to be honest, so hard to believe this is the cause of thhe flooding - the pattern / flow rate must be well off.

Ian.

Hmmm... RockAuto is going to be VERY expensive for gaskets, since they send parts from multiple locations, so if a gasket comes from location A, that's 49p plus £10 postage please. Another gasket at 62p also attracts a tenner postage. Are these bits readily available in the UK still? Guess I need to google my local (?) Isuzu dealer and see if I can get that stuff locally.

Injectors are £19.99 each, plus tax, £22 shipping, plus duty and VAT, which is a great price.

Ian.

Hope the photos are useful. There's no need to remove the rail to get the injectors out, but I'd suggest degreasing and washing the area within the 'U' of the inlet tract so that as much muck is removed from that area before parting the seals from the rail and inlet header (bores where the injectors seat).

Anyone would think I didn't need to be at work tomorrow... eek...

Ian.

Two sets of injectors ordered from Rock Auto (Thanks all). Yes, you did read that correctly, I effectively ran a 24 hour group buy and added a set on for maz_r so they should be here in 5-12 days according to the site (cheapest postage option).

I didn't order the gaskets and other bits as none were going to be shipped from the same location, so some of the smaller gaskets were going to turn out at £12 rather than £0.59 and so I need to find a better (probably more local?) source.

Haven't touched the car tonight, but did look at some youtube videos of people cleaning their own injectors using ultrasonic baths etc. Has to be worth a go, surely, even if only for the sake of trying it? One video shows a guy using a syringe attached to a can of carb cleaner - the plunger removed and injector inserted into the plunger end, then tube from the carb cleaner inserted into the other end. He then squirts carb cleaner into the syringe (pressurising it) and has button rigged up to a small lead acid battery to energise the injector and release the carb cleaner through it. He runs carb cleaner through both ways. I wonder how effective that is - I'd want to make a 50Hz generator instead so it 'buzzed' the injector to get more actuations in for a given volume of cleaner, the crux of it really is whether my injectors are failing due to internal damage, wear or just (washable) contamination. Enjoy: https://www.youtube.com/watch?v=_NMM6Mk ... e=youtu.be

The other video used an ultrasonic bath like you'd use on jewellery etc and placed the injectors into that for a bit. Usually those things are filled with water, but I can't see that being good for an injector, so if I tried it, I'd try using carb cleaner I guess. Outside! More enjoyment, there are also DIY ones... https://www.youtube.com/watch?v=Baw_29n5vbM And the DIY... https://www.youtube.com/watch?v=JWfnMN7Mlfo

Ian.