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ESPRIT 85 turbo start issues


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Dear colleagues

I still have a hard time to start my recently acquired 85 turbo.

I managed to start it up several times, but there are definitely some issues.

So now I started searching for the problem!

Ignition is there, but I do not know if it is strong enough.

checked compression:

cyl 4: 115PSI

cyl 3: 116PSI

cyl 2: 118PSI

cyl 1: 120PSI

this has been checked with throttle full open and engine cold ( as I have not been able to start it)

Any comments on these compression figures, are they normal for a cold engine?

Could this be the reason for the poor starting?

Note that I have tried already a lot of times to start it, plugs are wet, so there may also be some fuel in the cylinders eventually washing out the oil.

Will try to start the car and measure the compression again when hot.

Any comment is appreciated.

Merry Christmas and a happy new year !

Marc

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Compression figures look adequate.

Wet plugs, good, as fuel is getting there.

You have ignition, but is it on the right cylnider at the right time? Has anybody disturbed plug leads, distributor etc recently? If so you could have 1&4 swapped, and 2&3 swapped even if 1 or 4 line up with just before TDC.

Other than that, what colour is the spark at the plugs? (blue or yellow)

Andy

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Andy

thanks for your feedback !

good to hear that compression is fine, hope it will come up to 130psi if the engine is hot.

don t know about swapped leads, if I manage to start it up it runs fine, after a while.

Maybe parts of the distributor or the ignition are corroded, ignition may become too weak then, what do you think about that ?

Or the carburators give too much fuel ?

Tonight I will try to start it up again, hopfully I can have it started and then do the compression test again with hot engine.

Kind Regards

Marc

I ll check the color of the spark, guess it should be blue ?

Marc

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I wouldn't get too fixated on the compression. A lawn mower engine starts reliably with much lower compressions.

You have fuel and spark which are the essential ingredients. Now you just need to make sure you have enough spark and not too much fuel and the spark happens at around the right time. The fact that the engine runs sometimes means that the plug leads are in the right order. Ignition timing has to be only approximate for an engine to start so don't worry too much about that.

Try less choke to begin with incase you are flooding the engine and do what you can to make the spark stronger.

S4 Elan, Elan +2S, Federal-spec, World Championship Edition S2 Esprit #42, S1 Elise, Excel SE

 

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I worked a bit on the ignition.

Removed the box and the ignition amplifier (Lucas AB14) seems to be quite new.

I also have a spark from the coil, cannot judge if it is strong enough. None of the connections were corroded.

So now I will have to remove the distributor and check it.

From what I read here on the forum that can be a tricky. - let's see.

Cheers

Marc

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Given fuel mixture to the cyliders, adequate compression, and a spark at the right time, any engine must run. As you have wet plugs, you obviously have fuel to the cylinders, but you may have too much - having flooded the engine by overenthusiastic throttle pumping, for example. Every depression of the throttle squirts a bunch of fuel down the inlets, this is to give good response to sudden throttle openings. I find using the choke and not touching the throttle at all gives me good cold starting on my 82 Turbo...then I let it run for a bit before teasing the throttle until she gets used to the idea of working! Other than that, it'll be ignition related and the first thing is to see what sort of spark you get if you disconnect the lead from the ignition box to the distributor..when you crank the engine, you should get a good, fat, blue spark at least 5mm long. Be careful not to give yourself a shock or ignite the carburetters... If you have a good spark, then it's down to plugs, plug leads, rotor arm, distributor cap or timing. I've found the connections from the distributor to the ignition box are liable to develop high resistance and stop the sparks that way, so any connectors there are well worth a look...that would be my bet for the most likely cause, as it gives intermittent total ignition failure. Good Luck, Engel, it's all part of Lotus ownership....!

Scientists investigate that which already is; Engineers create that which has never been." - Albert Einstein

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My 83 Turbo had similar starting issues with the plugs being wet. Couldn't figure why the carbs were flooding? Checked float clearances, needle valves, etc but she still flooded. Took the plenum off a bam she started up like it was fuel injected.

The problem ended up being the set screw on the vacuum actuated diffuser valve was loose so the valve remained closed causing the flooding at start up.

Since the valve is an emission device to prevent fuel vapors from the carbs coming back thru the turbo and out the air filter I removed the valve and plugged the vacuum line.

Car starts great even on cool to cold mornings.

Louis

83 Turbo

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Thanks a lot for your feedbacks.

I have removed the distributor to find out that it was new.

Well, taking it off was quite easy, but putting it back on will become a real challenge ! (clips !!!!)

So ignition side doesn't looks that bad.

I will continue to search on the fuel side.

Louis suggested a few things that may be interesting here.

It'll take a while though until I have everything together again.

Marc

post-4237-1199097393.jpg

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There are a lot of peole who say do not use the blue dissy caps, use the black ones, there are issues with poor spark with the blue ones.I'm going to state the obvious, the HT lead from the coil isn't in correctly, but that could be because youo had to do that to turn the pod round, and you were going to correct that once it wasback in place.

Andy

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thanks Andy

That is interesting. I noticed that one of the contacts is not perfect on my blue cap, that means it is partially covered with blue plastic. Think I will rework that before refitting ! and if it doesn't work maybe get another one.

You were right, I had to undo the main HT lead and I will refit it when I will build the stuff together again.

Wish you all a happy new year !

post-4237-1199119818.jpg

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Well, I inpected the whole ignition system and it does not look that bad.

I have a spark at the plugs and none of the ignition components looks corroded, a few items even look quite new (AB14, dizzy cap, rotor)

Now I managed to get the dizzy cap back on (not an easy thing) and it still does not start.

It sometimes ignites, but does not start.

After a while the plugs are wet then !

So I am where I was before.

Louis

Can you tell me where the vacuum actuated diffuser valve is located, I wanted to check that too.

Note that mine is a UK spec car, so I am not sure if it has one.

Any comment is appreciated.

Marc

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How quickly is the engine turning over when you try to start it?

Have you checked how strong a spark you get at the plugs themselves? Take out one of the spark plugs and crank the engine over with it attached to each of the plug leads and the plug resting on the cam tower where there is no paint). See how strong a spark you get. Should be nice and fat and blue.

Did you try starting with less or no choke?

Do you have the throttle open or closed when you try to start the engine?

How old is the fuel? Has the car been standing for a long time e.g. months?

S4 Elan, Elan +2S, Federal-spec, World Championship Edition S2 Esprit #42, S1 Elise, Excel SE

 

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The diffuser valve is located at the inlet on the diffuser as it comes off the turbo. On the outside of the diffuser is a vacuum actuated pot that moves the valve lever arm. Maybe someone has a picture handy that shows the valve.

From my experience if your plugs are wet then its flooding. Try taking the plenum cover off or at least loosen the bolts to where you can get a good gap and see what happens. Be careful not to tear the gasket. If she cranks up then there is an air intake restriction somewhere.

Also check the chock lever that connects the chokes on the two carbs. Double check and make sure it allows the chokes to fully close.

Louis

83 Turbo

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Another old trick to help non-starting engines is to take the plugs out and heat them up on a gas stove, then replace them and start up. Often helps....but I'm beginning to think your problem is timing. Perhaps checking the timing from first principles, engine at TDC on firing stroke for no.1 cylinder (set the cam timing marks together, they're the dots on the rear face of the cam pulleys) and check you have TDC on the crankshaft, rotor arm pointing to no. 1 plug lead, and all the other leads in sequence given the direction of rotation and firing order. Worth a go.

Scientists investigate that which already is; Engineers create that which has never been." - Albert Einstein

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thanks a lot for all the tips, will have to check out things one by one.

I have added a picture of the engine. Can anybody point to the area in which the vacuum actuated diffuser valve is located.

post-4237-1199474173_thumb.jpg

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Still not running?

Other Things you could look at:

The air gap on the distributor pick-up (i.e the gap between the magnetic rotor & sensor)

The resistance of the sensor - its not uncommon for them to break internally where the leads exit the dizzy.

(I know both these would potentially give no spark at all but could also be intermitant)

Ensure that your static timing looks OK - i.e pick-up is aligned with ridge on rotor at maybe 10% BTDS

You could try replacing the condenser that sits inside the Amplifier unit (very easy)

You could try removing the plenum, full throttle (no pumping!!) & cranking with your plugs out to dry out the cylinders - then try Easy Start to prove whether it is electrical or otherwise.

If the engine was simply catastophically flooded, a guaranteed way to start is by tow-starting...

Failing all that try a mobile tuning service to get some accurate diagnostics!

good luck - cheers Steve

Oh - and are you 1001% certain your plug leads are where they are supposed to be???!

Edited by 910Esprit
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what is the best way to turn the engine manually ?

- I want to set it to TDC (check on gearbox marking) and check position of number 1 HT lead.

in what direction will the rotor rotate (looked at it from the rear) ?

still a lot of things to check - what a hobby ! :-)

Cheers

Marc

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what is the best way to turn the engine manually ?

- I want to set it to TDC (check on gearbox marking) and check position of number 1 HT lead.

in what direction will the rotor rotate (looked at it from the rear) ?

still a lot of things to check - what a hobby ! :-)

Cheers

Marc

Hi Marc,

It rotates all anti clock wise and your rotor will in 12 o'clock position at TDC. (normaly by n

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Hi Marc

I don't see the valve on your diffuser. It would be located between the turbo and the word TURBO stamped on the diffuser.

To set the engine at TDC remove the plugs and put the car in 5th gear. Lean over trunk to look down to the timing pointer on bell housing (it may have a rubber grommet cover, mine didn't). Push the car forward (NEVER BACKWARDS!) until the pointer is lined up with TDC mark stamped on the flywheel.

You could also jack up the car and turn the crank pully. You may have to turn it two revolutions. Double check that the TDC mark in lined up with pointer on bell housing.

Now check your timing marks on the cam pulleys. Some pulleys have colored dots, mine is just punch marks with no color.

Louis

83 Turbo

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thanks a lot for all your help all tips were helpful - finally I have a result.

It is starting, this time with choke.

But with choke it stays around 1000rpm - is that normal? read somewhere that with shoke fully pulled it should be around 2000rpm.

Have removed the dizzy cap again and cleaned the whole ignition system with contact spray and WD40.

After it has run for a while (5-10min) it starts perfectly.

I have checked compression after a 10min warmup. Engine is not completely warm!

Figues look now better, still not at 130psi, but closer.

compression Lotus Esprit turbo 85

cyl. cold (PSI) at 45 deg (PSI)

1 120 122

2 118 120

3 116 120

4 115 120

measured with motometer compression tester range: 250 PSI

found also in the manual that compression should be min 120 when cold , min 130 when hot. So guess compression is ok.

- I have added a few videos on youtube

Maybe some of you can comment, does it run as it should?

They are no "Spielberg" movies, but most important is the sound.

Have a look and tell me what you think.

Movie 1

description : idling just after start up - sounds a bit strange

Movie 2

description : accelerating after warmup - better

Movie 3

description : starting after warmup - I am happy with that

Movie 4

description : moving backwards - strange clutch sounds

Cheers

Marc

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Starting up cold (with choke on) it sounds like the carbs needs some twiking. Sounds like one carb is running rich. Do you have a manometer to check the carbs? Can you tell if both chokes are opening the same amount?

From the beginning the plugs were wet with fuel but she wouldn't start. Now it starts with the chokes on that means its getting even more fuel. Strange.... I guess she demands it and if she ain't getting it she isn't going to start until she gets it.

Another unique Lotus learning experience.

Louis

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Marc

I dont like the sound of your engine idling cold - It sounds too mechanical - although it could just be the recording. Can you locate where that 'deisel' noise is coming from. If its simply the exhaust, or even the top end then I would not worry too much, If its from the side of the block It may be more to worry about.

Also your 'hot' start still has a lot of steam in the exhaust. I would not expect that from a hot engine. Does the car consume water, Is there any mayonaisse on the filler cap? what does it smell like!!?? I'm just wondering whether its water or unburnt fuel or both!

Lets hope its simply the recording making it sound off!

cheers Steve

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thanks for the comments !

The engine is not completely hot, it has run for about 10 min in the garage.

As the car does not have a registration yet, I cannot drive it on the road.

For how long should steam be coming out of the engine if the car has been standing for a while ? 10 min ?

Yes there are traces of brown jelly in the expansion tank, but only a bit. When reving the engine the level in the tank increases, no bubbles. - is level increase normal ?

What about the rpm with choke - is around 1000rpm ok or should it be higher?

How can the carburettors be cleaned, is dismounting required?

Now I am already happy that I can start her up. Just choke will do. It is best with my current setup not to touch the gas pedal at all, otherwise it dies, - and plugs become wet etc...

Will keep you updated

Cheers

Marc

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  • 7 months later...

i have not looked at the other posts, but black dizzy cap, from halfords,

Лотос - для тех которые знают разницу

ENIGMA for those who are paranoid or download one :)

 

 

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