Unusual starting problem

[SimonW]

That's great. Does the Injector pulse width 18.4ms look okay for: car off, ignition on, when running it's around 2ms?

The car idles fine, starts at around 1100rpm then settles at 950/975rpm. I've not adjusted anything with the timing, CO or idle screw.

Is there a timing light that you would recommend?

[HJ2]

It would be very interesting indeed to see if the base timing is correct, so start there and keep us posted on that one.
Perhaps you have already checked your new injectors for leaks as well? It is always possible that even a new component has a failure. If you have a known good old injector you can sequentially exchange it for the new ones to see if the problem lies here.
Also check the bond straps that ground the injector and manifold.
Finally you can also check the MAT sensor and CTS sensor to see if there is no garbage temperature reading that is responsible for throwing the mixture off (rich).

Good luck!

[SimonW]

The injectors have been checked new and old

The cold CTS and MAT data is below:
Ambient temp:22.9
CTS: 21.5
MAT 25.1
Op. temo.-temp 57
Coolant Raw 115.0

Even after starting and running well, the new spark plugs are black with carbon after 20 mins at idle speed.
I'll take a look at the bond straps and check/set the timing next week (once I receive the timing light).

[Rambo]

Is there a timing light that you would recommend?

The names "Gunson" and "Accuspark" spring to mind from hearing other people talk about them

However, I don't know whether they are using "Gunsons" as a generic name for a timing light or not. A bit like people referring to a "Hoover" (these days a Dyson) as a vacuum cleaner or a "Bendix" as a washing machine

I'm sure someone more knowledgeable ie Dapinky, LotusflashermanPhil ..... will be along soon with a recommendation and a link. There are plenty of choices on EBay, Amazon etc......

[Fredjohn]

Is there a timing light that you would recommend?

Whatever make you get make sure the lead is long enough to reach from the plug lead (or whatever spark source used) to the timing mark, plus a bit!!!!!!!

[dapinky]

I'm sure someone more knowledgeable ie Dapinky, LotusflashermanPhil ..... will be along soon with a recommendation and a link. There are plenty of choices on EBay, Amazon etc......

This is likely a question to someone much younger than me (and therefore, by default, also Phil ) - my strobe light was first used by Fred Flintstone and handed down to me when he gave up driving! (it doesn't have all the fancy bits like the 'modern' ones and sits inline with No.1 HT lead - with suitable extension pieces etc).

[GeoffSmith]

The data looks OK, next is to do the same thing and then start the engine.

[SimonW]

Hi,
This is with the Elan SE just started from cold (sorry the image isn't clear):


I'm logging the data now until the fans cycle.

[Bern]

I've got a timing light like this but the pickup for the plug lead isn't long enough to reach the lead without removing the engine top cover, and I run it from a spare battery as the leads won't reach the Elan's battery. And it seems like you can either have the strobe on the timing mark, or be able to see the mark, but not both at the same time!

Apart from that it's fine!!

[SimonW]

Thanks, I'll take a look at the timing light!

Please find my ElanScan data attached. If anyone could take a look I'd be most grateful as I don't really know what I'm looking for:

[SimonW]

Please could anyone recommend someone that could check my Elanscan data?

[Simon_P]

Please be patient - It isn't a quick job and every hour someone spends looking at your car is one less doing their own... I could for example be answering Clemo's PM. and hes been a member longer than 4 days.

You say that you are recommissioning your car, so any number of things could be wrong with it.

Start by setting the base timing and the idle. If you don't do that first then everything is a guess.

Check all of the earths, plug and pipe connections.

Fully warm your injector pulse width is about 1.75 to 1.8 and it should be nearer 1.3 to 1.4 so yes it is rich. (there is no point checking it at any other temperature than fully warm)

With a quick glance at the sensor outputs they seem ok.

You can ignore the AFR readings, as your car doesn't have an O2 sensor it has a CO pot to calibrate it.

So if your sure everything is in order... you could adjust the CO pot.

[Simon_P]

Just to add that after changing injectors you should adjust the CO anyway to account for the difference in injectors.
also
It could be that running rich and poor starting are separate issues.

and re check the timing after adjusting the CO

[SimonW]

There's absolutely no expectation to respond to me over anyone else and I apologise if my posts appear impatient.

Yes, i'm new to the forum and Lotus Elan ownership, learning my way around and asking openly for recommendations of who to ask or see to solve my starting issue and start connecting with Elan owners (hopefully on the road).

Thank you for looking at the data and your advise
I'll order the timing light and research how to set the CO, then report the progress

[Brit-Car-Nut]

If you find the injector pulse width is still wider than normal after checking for inlet vacuum leaks, check the engine temperature in Elanscan. It is possible the coolant temp sensor (CTS) has failed and is giving the ECM the wrong information. The dash gauge might read normally, but that uses a different temp sensor.

There is a post on here that provides the resistance value for different temperatures that would help you diagnose a bad CTS (very common failure part).

I found it under the WikiLEC topic at the top: http://wikilec.com/view/Coolant_Temperature_Sensor_(CTS)

[Simon_P]

The CTS/MAT/MAP and ambient pressure traces are normal and map to another idle from cold to fans cycling scan that I have, but the injector pulse width is consistently higher.

Timing is 2° retarded but that may be an ecu correction, hence the comment to re check.

[Brit-Car-Nut]

You need to check / set the timing in "service mode"

The pulse is ecm adjusted based on engine temp and throttle position. The longer the pulse, the more fuel is supplied.

It would be nice if you tell us exactly which version M100 you have... NA, Turbo, Turbo S2?

And what modifications have been applied already.

It might help too if you let us know who / where you got the car. It might have some history that has been discussed on LEC before.

Is it possible someone has added a manual Boost Frequency Controller kit that bypasses the MAP, etc.

[SimonW]

Thank you for the extra info.

It certainly makes more sense to why the car is running rich and why it would be more difficult to start with the extra fuel.

There are no modifications, it's a completely standard 1990 Elan SE Turbo (UK) which I purchased from eBay around 18 months ago near Holmfirth.

[Brit-Car-Nut]

I am in the US, so can't advise a specialist near you, but someone else on LEC will know who to recommend to you. It might be a bit of a drive, but having someone that knows the car's systems intimately might see something that is different that you wouldn't even realize it has been changed.

I would lower the coolant level, remove the CTS and, using a sauce pan, stove, thermometer and ohm meter check that the CTS is behaving correctly.

I believe the CTS specific to the M100 (per Lotus) is very expensive but a proper replacement is available under a different model part number.

I found an interchange listing that says the CTS part number from GM is 25036979. Google it and find other supplier part numbers for that.

The Esprit part number is A910E6928F which is Lotus Obsolete, but SJs is offering it for £19.00

Rock Auto has multiple listings that interchange with that part number and in the US they are as cheap as $3.17
and as much as $13.02 (Delphi is a GM company)

AGAIN: If this info is incorrect, would someone let me know and I will change the interchange list I have.

[Fredjohn]

LEC member Neil (enright) is close to you in Nottingham, but haven't seen him on here for ages. Perhaps send him a pm?