Misfiring

[Pascal]

Hello everyone,

I have same king of trouble since yesterday :
- misfiring when engine (normaly) hot, around 3000 rpm, falling to 1000 rpm, and cough
- when cough : a bit of white vapor and strong gas smell (have you got this gas smell ? )
- orange light 'engine' on after 'calling' a bit the power
- light off when driving low, engine back to normal operation, stop misfiring

- when back home, stop engine hot :
boiling noise from engine BUT I HAD THIS BEFORE FOR LONG (do you have ? )
the coolant level is high (up to durit input) in the tank BUT I HAD THIS BEFORE FOR LONG (do you have ?)
no mayo anywhere
no loss of coolant , level remains stable, THIS FOR LONG : NO PROBLEM

- start is perfect when cold,
start almost impossible when hot.

I see no sign of head gasket problem but I really wonder about the high level of coolant when hot.

I plan to ElanScan but I have a computer problem (no, not the Random Access Memory gasket ! ! ! )

Tanks for sharing experience,
Pascal - France

[Pascal]

Hello LEC friends,
my good old calipso (faded to pink) red had some severe cough 5 days ago (after 500 miles without trouble the previous week ends).

I spent time reading the wiki and forum, many thanks to all of you : LEC is a gold mine for informations.
After discussing with LEC ' HJ2, Fred, Peter D, Epipete, Geoff ... (you're great ! ), I open this line.

My coolant is the green one. Level is standard.

1° when driving : car suddenly having serious cough around 3000 rpm, self lowering to 1000 rpm, and maybe engine running on 2 or 3 cylinders.
2° sometimes - when coughing - : smoke with strong gas smell. Seems to be white (grey ?) smoke.
3° i notice a lot of bubbles at the return of the coolant to the tank as soon as the coolant is becoming hot ( 65 °C ? ).
4° a lot of poping when deceleration
5° smelling gas when start from cold
6° after a severe cough : just driving slow and the engine is fine again. Acceleration ... orange 'engine' lights on.
7° big expansion of the (hot) coolant in the tank when stopped, level rises up to the return inlet, making difficult the coolant input in the tank.
8° temperature gauge almost never higher than 1/4
9° paperclip test : code 15 just after the problems.

Key words seems to be ...
- overfuel
- coil pack
- CTS defect
- bubbles at the CTS / wrong measure
- bubbles in the circuit / overheat
- injectors
- air lock
- HG - head gasket - failure

What I did :
- lowering the coolant level a bit : -1cm under the normal level when cold
- tighten very hard the tank cap.
DOING THIS, THE CAR NOW WORKS SIGNIFICANLY BETTER !!!
- Almost no more poping.
- No cough.
But I always have the bubbles at the coolant tank inlet when (normaly) hot. HJ2 has same, and you ?

Then this morning I notice :
8° black soot (in tears, spots shape) on the ground in my garage at the exhaust surroundings. Never seen that before.

I join an ElanScan file if someone can find time to investigate and share comments.
- The car works well at the moment but I suspect something deteriorates - Wonder if it could be serious ( HG fear !)
- I also wonder if a too high level of coolant could somehow "flood" something, then the cough.

Have a good day,
Pascal - France

[DeanG]

I had some similar issues. An intermittent bad fuel injector caused overheating of the controller that caused the associated injector to fail intermittently. The resulting mixture caused my catalytic converter to fail. A bad smell (sulfur) is an indication of a bad catalytic converter. I hope this helps. Good luck.

[tb10]

I'm not sure if Pascal's car has a Cat as his car is a 1991 variant and I didn't think that Cat's were put into the cars for the European market when they first came out (unless Pascal has now got an S2 of course!)

[Pascal]

Hi,
no cat but the fuel injector is a track.
Pasc

[Pascal]

Hello, do you know ...

what kind of failure code could appear if I have a fuel injector trouble ?

What about code 15 ?

Pascal

[muley]

Hi

Code 15 is faulty coolant temp sensor. I got a new one from Rockauto and the problem was fixed. Default value is -60 deg Celcius which will cause over fuelling...

Jim

[Pascal]

Hello,
I used the Elan yesterday evening, working fine but :

- obvisously not the max power (I tried a 120 hp old Elise that was significantly more agressive). Jauge showing maxi +0,5 bar.
- idle when cold : 1600 rpm (1100 when hot)
- very difficult to restart when hot
- still the bubbles at the coolant tank inlet when hot
- engine noise has changed (not as soft as before).
- I do not feel the durits are very hard (but i have few experience. someone told me the durit would be completely hard if it is a HG problem ??? )
- green coolant clean

I await for a new tank cap from SJS but i suppose it will not make the difference.

I plan to change all the thermostats (CTS, Jauge sender, fan switch and thermostat ... 300 GBP ! ) , but I wonder about a possible alternative problem : injectors ? Coils ?

How could the ElanScan help / how to read what parameter ?

Tanks for any light in the night ...

P sc l

[HJ2]

Hi Pascal,

A lot to read about what's happening when driving, but not what you have done!
Did you set base timing as per manual yet?

I still don't believe your head gasket is leaving the car early....

Also 300 GBP sounds steep!
Better drive to Delft then, as I am a lot cheaper

[GeoffSmith]

Pascal,

Sorry for not having time to look earlier but don't go mad buying things just yet. I've just taken a look at the spreadsheet you posted last week and you appear to have fault flags 0x16 set which means that the MAT, TPS and CTS readings were all low. As all three signals seem to share supplies and pass through the IHC connector, I would suspect the IHC connector or the ECU and/or connections.

A quick check that the TPS is correct is to turn on the ignition (but not start the engine), run ElanScan, look at the <<Throttle>> output and floor the throttle: The reading should increase from 0% to 100%.

If the CTS reading is low then the ECU thinks the engine is cold and the idle speed & fuelling increases and you will get run very rich and get a wet and sooty exhaust.

An ElanScan log (save the .ecu file, zip it and post on LEC rather than the Excel files) from cold until hot would be useful, especially if you can reproduce the problems.

Geoff

[HJ2]

Enough homework for now

[Pascal]

Thanks,

the base timing was set by Franck FVH and I remember he has difficulties to do it despite his great experience. Could something else be erratic and pollute his setting ???
1° Also, he made this more than 2500 km ago, could this change spontaneously ? How often do you set the base timing ?

2° Could someone file a "normal" scan here or give a link, so that i can compare to what i read ... at least for my own culture and understanding -

I do some more tests, have a beer and come back.
I still hope to be in Limburg but i fear a bit a possible breakdown - i must come back to work (brand new job since this week, not time to play joker ! ) ...

3° I note ... open bar in Delft

[Pascal]

just a quick feed back to Geoff before harder investigations :

Car cold, engine not yet started :
--> throttle operates properly from 0 to 94 % (adjustment needed).

But - (i didn't notice that before) : Coolant T° : -1 when MAT T° : 24.043
True garage temp is about 22 / 23 °C and my beer about 12°C so what about this -1 ?

I started the engine : coolant -1.75 °C , and MAT 22.94 °C (seem to be the value on my garage thermometer).

After some seconds , coolant rises to -1 , I stopped the test to keep cold (to put my fingers in if needed, or make another cold test).

During the previous test some days ago, i did not record from completely cold/engine off, and did not see the -1 .
It seems (from previous test) that the coolant temp rises normally and reaches 60/75 °C after some 8/10 minutes.

Paperclip code is still 15.

P sc l

[GeoffSmith]

There is something wrong with your coolant temperature sensor (CTS) or wiring - high resistance gives a very low temperature reading. Have you changed the CTS? The CTS is the blue one in the Wiki diagram.

[Pascal]

Hello,
tank you for separating the two topics, i likely made a mistake somewhere.

The CTS is one of the parts I planned to buy to SJS , and -1 °C is one more reason.
I planned to replace all those parts : CTS, fan switch, thermostat and jauge sensor, so all the parts on your sketch (in fact I previously used your wiki-sketch to clarify the parts references and names ) .

1° --> I have purchased ( french supplier : Oscaro) a "cold 95°C" Denso fan switch (not yet arrived) , this will clarify the compatibility doubt. I don't know yet if the Denso is exactly the controversial Mazda.

2° --> I read on another topic of the LEC that someone had a sticked thermostat. This could create a trouble in the coolant return. The cost is 10 GBP, not the worse in the list so I plan to buy one.

3° --> I received this saturday a yellow tank cap from SJS, it fits perfectly my tank (GM brand) . I have seen some tanks pictures on the LEC, they are white and you cannot see through the plastic. Mine is translucent plastic, I can see through although it is not easy.
So there are at least two kinds of plastic tanks and potential cap compatibility problems.
It is obvious, but i confirm : this did not change anything (but it is a pleasure to fit a cap with a smooth operating gasket).

4° --> herewith parts list offer from SJS , some SJS équivalents in.
SENDER UNIT, TEMP GAUGE A100M0042F EACH 27.85
TEMPERATURE SENSOR, (For Radiator fans & Recirculation pump) SJ100E0014 39.00
THERMOSTAT AND GASKET (SJ Sports) SJ100E0021 9.56
TEMP SENSOR, (For Engine managment) A100E6373S 59.34
Comments are welcome ... that's some money.

Regards,
Pascal
Hope to be at Limburg Lotus Tour , 21st, june.

[dapinky]

Pascal,

The CTS (#A100E6373S) is expensive from Lotus - there is a cross-referenced one "Fuelparts WS1037" which is easily available in UK and Germany, so should be good in France. It is a Nissan/Dawoo (and probably others) standard part.

The radiator sender (# SJ100E0014) is a standard General Motors item and comes in various settings so you can decide when the fans operate - probably availlable in France, but easily availlable from Rodney Dickman in USA.

[GeoffSmith]

Pascal,

I would recommend you buy a CTS (bleu) and thermostat. Replacing the temperature gauge sender (vert) and fan thermal switch (rouge) will not cure your problem.

As Dave says, cheaper alternative CTSs are available or if you want to buy from SJS then buy the one listed for the Esprit (A910E6928F) at £16 rather than the one listed for the Elan (A100E6373S) at £59.34 - THEY ARE IDENTICAL IN ALL BUT PART NUMBER AND PRICE!

There is no evidence that your thermostat is not operating properly but they are comparatively cheap and it is always useful to have a spare.

Unless your temperature gauge appears wrong (normal temperature at less than ¼ scale and fans on at ~¾ scale) then the temperature gauge thermal sender is probably OK.

Unless you want the reassurance of your fans starting up at a slightly lower position on the gauge then I would not worry about the fan switch. Once you cure the problem, you can run ElanScan to confirm that the fan switch is operating correctly.

Geoff

[Pascal]

Hello again ...

I had the stupid idea to drive a bit , I ended stopped 6 km from home.
Impossible to start again, even after 1 hour cold.
Car back on a flatbed truck.

It begun with the engine lowering, then like turning on two cylinders, smoke cloud (black soot around exhaust) and strong fresh gas smell, and finally stopped.
I let the car become cold (1 hour), and cut the battery circuit 5 minutes.

I have now the car back in my garage (my mechanics is in holydays this week !!!) and I don't know what to do with it.
Can't run an ElanScan with a stopped car
What could I try ?
Did I flood the whole engine ???
Any idea and mockeries are welcome.

P sc l

[Pascal]

Hello,

1° CTS is dead ( I await one from SJS, Esprit ref, thanks Geoff) , I read : 23000 ohms when 22 °C, this is out of the hot range.
( 20°c / 3400ohm /// 4 / 7500 /// -7 / 13500)
Could this alone stop the engine ?

2° I have sparkes from the lead plug at every 4 wire. Does this mean that the coils are working fine, I think yes.
3° hall sensor : I could'nt open to look at it, cover seems to have 5.5mm screw heads ? The spigot is in perfect condition and the sensor is turning properly. I hunt a 5.5mm key to remove the cover.
4° still smells fresh gas at exhaust.
(5° code 15 at paperclip test. Fault 16 on ElanScan during last test.)
6° Starter turns, sparkles at 4 plugs. Hissing noise Under bonnet : I think air is coming in. But no firing noise at all.

Any test suggestion is welcome (as long as I can do it on a stopped engine ), awaiting for the new Esprit cts.

friendly, Pascal

[Pascal]

Hello,
thanks to friday evening time, I took the plugs off, you can imagine they were dark black. I cleaned them and the engine accepted to start, in a nice blue cloud. Idle was errating.
That was the opportunity to ElanScan ...
definitely crazy CTS : was around 33°C, then changing from 33 to ... minus 40, or zero or -13 or whatever. Never seen that before.
Air/fuel ration and advance also turned crazy.
Awaiting for the CTS spare ... I shall also change the spark plugs !

Pascal