2 cylinder Elan

[elaverick]

So on the latest episode of help the mechanical idiot... I currently have a 2 cylinder Lotus.
My wife took it for a run to the supermarket last week, just a quick 5 mile jaunt. Ran fine all the way there, but when she started it to come back it was making a terrible noise (misfiring).
Sure enough sitting at home its making a bloody awful noise, so I called out the AA on homestart to find out if it's safe to drive to a garage.
Having had a good dig around, it turn out that its failing to fire on cylinders 1 & 3. Spark is good, plugs have been swapped to check them out (no difference). There's good compression (comparable to 2 & 4) on the faulting cylinders, but the plugs are staying dry.

I thought head gasket initially, but as the AA fella pointed out, why is it failing on two cylinders that aren't adjacent to one another. He suggested maybe an injector failure, but if that's the case, then why would two fail simultaneously.

I have a feeling regardless of the problem it's going to mean a trip to Williams Automotive, but does anyone have any pointers as to what I might be looking at (so I can get an idea of cost as much as anything), and whether or not it would be safe to limp it either the 13 miles to the garage or the 3 miles it would need for the AA to recover me the rest of the distance.

All suggestions gratefully received.

[HJ2]

My bet is on either an injector failing (2 injectors share part of the harnass so 2 cylinders fail) or a coilpack failure (waste spark ignition) so if one pack fails, 2 cylinders are gone as well.
The good thing is: Coil pack failure and injector failure result in 2 different cylinders failing, so with your description you are pretty much able to determine the cause of the failure.
The bad thing is: I can never remember what root cause is connected to what cylinder pairs

Somebody will show up soon explaining it better then me and WITH the correct info to get you sorted. Meanwhile you could do a search on this on the forum as well to help you out. I am pretty sure it's on here somewhere

Both repairs can be done in situ by any moderate experienced mechanic!
Also: Start by checking and re-torquing all of the bond straps on the engine, intake, coil packs and fuel injectors!

[wayne]

Coil packs are for 1&4, 2&3 Wiki

[HJ2]

So it must be an injector then.
Check bond straps and unplug one injector at a time to find the defect one.
I would replace them all if they are the root cause

[Bern]

Just had a look at the electrical manual and it looks like, for the injectors, 1 and 3 are connected and so are 2 and 4. So it definitely looks like the injector wiring.

However as both have failed I'd check the connectors and wiring before replacing the injectors, as both have failed I'd say it's likely to be the electrical feed to them rather than the injectors themselves. But, I've never had a problem with an injector so not had to look at them!

Electrical manual

The wiring diagram is about 1/2 way through, Engine Management, not sure if your's is an NA or turbo, but there are different wiring diagrams. I assume the turbo diagram is the one after the NA (the heading is cut off).

[elaverick]

Thank you all so much for this. I'm probably going to wuss out and get the Williams to fit it for me (unless it's a stupidly simple thing to fix), does anyone have any idea about the sort of price I'd be looking at for parts and labour on something like this?

[Simon_P]

Before you wuss out, try what HJ2 says and unplug injectors 1 and 3 one at a time. Also check the harness connector... It's simple and free!

[elaverick]

Before you wuss out, try what HJ2 says and unplug injectors 1 and 3 one at a time. Also check the harness connector... It's simple and free!

That's a price I like and a skill level I can aspire to
I'll give it a go tonight.

[alan e]

And when its fixed don't let the wife drive it, then it wont go wrong ever again

[dapinky]

Elaverick,

Many moons ago i had the same problem, and it took me many more moons to sus it out (and advice from a guru who inparted words of wisdom, which worked wonders)....

Basically, there are things you can check to establish if it is the injectors themselves, or the wiring to them...

First, turn on the ignition, but don't start the engine (or try to).

Then stick your head under the bonnet over the injector rail.

Open the throttle by hand (on the cam where the throttle cable operates).

You should hear each of the 4 injectors 'click' in turn - this is an inbuilt diagnostic for the ECU, but it doesn't seem to appear in any of the Lotus workshop manuals. Basically, they each energise and the click is the ball-bearing moving through full travel.

If one injector fails to click, then the issue is "probably" with the injector itself - but if 2 fail to click, then it is "probably" the wiring to the rail.

With mine, it was the multi-connector block at fault - there are 3 of them just in front of, and below the coolant reservoir - one of these blocks connects the fuel rail to the wiring loom (I can't remember which one it is, off hand).

I wiggle of the block and wires soon had all 4 injectors clicking correctly, and then i fired up the engine and all was good.

Having discovered the location of the fault, i turned off the engine, disconnected the block completely, cleaned up all terminals with a good spray of contact cleaner and fine wet/dry. Then put it all back together.

It is still going strong to this day - i don't know if damp had got into it in the past from an overflowing (or poorly topped-up) coolant reservoir, or elsewhere, but it obviously got there somehow.

It may or may not help you, but it is a simple (and free) check to make.

[HJ2]

[rip]

I have had 2 fail in the last 2 years so, when the second went, I had a good idea what the problem was.
As Dave points out, you can hear them clicking. You can also hear them with the engine (trying to) tick over but you will need a stethoscope or long screwdriver touching each injector in turn with the other end to your ear to hear them.
There is a good guide to replacing them on the Wiki & it took me around 90 minutes to change all 4. It is a bit fiddly but certainly achievable.

I used replacement parts from Rock Auto but be careful: I am not sure if they have corrected it but they listed the same part for NA & Turbo. This one is wrong for the turbo. They also list another, more expensive, one for the turbo only which is correct.
I now get a slightly lumpy idle at cold but otherwise it runs fine & seems to be more economical than it did with the old injectors.

[Simon_P]

Rip did you reset the Ecu and adjust CO after the injector change? Sounds like it might be a bit lean.

[elaverick]

@dapinky
Thanks for the tip. I’ve tired as youve suggested and I can definately hear 3 clicks. However the bit thats confused me is after disconnetcing injector 1 and trying again AND doing injector 3 and trying again (after reconnecting 1)... Im still hearing 3 clicks. I’m assuming the cylinders are numbered left to right sequentially here.
We’ve got Tom Day fuel injector services nearby so I might drop the car into them and see if they can assist.
Thanks for everyone’s help with this. It’s greatly appreciated

[rip]

Rip did you reset the Ecu and adjust CO after the injector change? Sounds like it might be a bit lean.

I thought it may be a bit lean.
I have reset the ECU a couple of times. I have not adjusted the CO but it has since been through an MOT & the emissions were normal.

[John_W]

I’m currently in Carcassonne with a 2-cylinder Elan.

A couple of days ago we were entering Rocamadour when the engine started to run very rough and had no torque; it sounded ‘orrible, like I had a hole in the exhaust, but at least the noise was useful to clear the tourists from the main street to let us get to our hotel!

I took the plug leads off one-by-one to identify which cylinders weren’t doing their stuff, and 1 & 3 made no difference: I therefore diagnosed injector problems (rather than coils which would have produced a 1&4 or 2&3 combination fault). Shortly afterwards the hotel asked me to move the car to let somebody else in to the stack - it fired up on all four and has been working fine since.

However, today it reverted to 2 cylinders just after we left Peyreperteuse and I had to nurse it back to Carcassonne. It runs, but like a bag of nails, and going up hills is interesting! The engine was far too hot (no hotter than normal) to investigate wiring connectors etc, so I’m going to do that tomorrow.

We’re 1,300 miles into a 3,500 mile trip, and I would like to complete it. So I’m looking for advice and ideas:
- does it sound like an injector problem?
- anything else it could be?
- are there any other diagnostics I can do? (I have not run an elanscan log yet, but would that show anything?)
- apart from wiggling Pinky’s wires and cleaning connector blocks, is there anything else I can do, given that I’m unlikely to find a spare injector in a shop here? (I can buy a suit of armour, though.)
- is it worth getting a garage to clean the injectors?
- To disconnect the electric input to the injectors (to definitely identify which one isn’t working), do I have to un-seat the thin wire clip? (not something I fancy attempting without proper tools)
- If I drive it in this condition will I do more damage?

All ideas gratefully accepted!

John

[lotustonybassplayer]

if you have the ignition on, engine not running, open the throttle you can hear the injectors clicking on and off use a screwdriver or similar on each injector to determine which if any are working or not

[HJ2]

Top tip!

You can get the staple-type fixture of the injector connector off with a fine flathead screwdriver & a pair of needle nose pliers or your wife’s pincet for all that matter.

Cleaning won’t help as the problem is electrical. Or else you would have 3 working cilinders, not 2
I hope you solve it

[GeoffSmith]

John,
Agree with HJ that it's most likely electrical so probably not worth cleaning.
If it's one injector going down (and dragging the paired one with it) you might be able to get it running on 3 if you disconnect the bad one. Be sure to try disconnecting both as disconnecting the good one may result in there being enough drive to make the bad one operational. If it doesn't improve then it is likely to be wiring or ECU output drive.
We are heading to Bordeaux on Monday so please give me a ring (sorry, rephrase that, give Sarah a ring!) if there's anything we can do.
Geoff
PS Have you tried Colin (Bolsom)?

[sideways]

I miss the days of the "Italian tune up"

I truly understand that with today's drivetrains that simply standing on the throttle, under load, on the street - with perhaps a modicum of Redex having been stuffed into the carb(s) is no longer a sensible thing to do.

But it did cure many ills.

Back then...