original Exige S1 177bhp ECM wanted

The Marketplace Parts For Sale / Wanted
41

Spent all day messing around with the Exige.

Not sure what’s changed but managed some minor wins.

So today’s achievements include:

I) The injector/fuel pump relay cutting in after cranking

II) The injectors getting a signal (Noid light flickering).

III) The Ignition coil pack getting a signal (sparkplug tester flickering)

Not sure why these parts are waking up, nothing tangible has been carried out. May be the battery had early stages of Sulfation which with multiple draining and charging together with the Noco is reversing!

Will try again tomorrow, with the scope connected, if same results and no fuel in cylinders, I will remove, inspect and test fuel rail and injectors. Will also try Topdon battery tester again as it may have given false results on the battery condition.

Never did find the front earth point, removed lots of stuff and traced the cable as far as I could before it disappeared heading towards the chassis on the front near side.

Based on the south coast.

42

That all sounds promising!!
If your car has AC, then getting to the earth point is challenging, as its behind the AC unit, which all needs to come out first!

43

Yes, about to start a new day of testing with optimism.

Aha, now that explains the hidden earth point.

AC was installed as an optional extra at build.

Not convinced it was one of my best decisions.

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Following this with great interest. How lucky we are to have such knowledge to draw on. Fingers crossed for a solution ( that’s the best I can offer)

45

Thanks for your support thommo,

Yesterday’s wins were short lived.

Carried out yesterday’s tests today with scope, lights, multimeter and battery tester attached, in an attempt to find out why it did not start.

I got intermittent injectors and ignition coil operations. The Topdon indicated the battery is 100% fully charged, has 386 cca, a little disappointing as it’s rated at 520 cca, but turned the engine over at 180 rpm so starting should not be an issue. Tried with the NOCO attached, still intermittent results.

I’m thinking relay, the dual relay for fuel pump and injectors may have a pair of burnt, dirty or worn contacts.

Alas it didn’t take long to rubbish that theory. All four relays on the cockpit rear bulkhead are the same, so swooped two over, no change. Just to support the findings I connected a test light to the yellow wire (live to No4 injector) and the engine ground by the oil dip stick, the light lit up each time the fuel pump kicked in. Oh well, on a positive note, it saved me the cost of an £8 relay.

Time to look at the next issue and ponder on the previous issue tonight.

Since I can’t smell fuel on the spark plugs when the injectors are functioning I suspect the fuel injectors are gummed up with old petrol. Only have a basic service kit (O-rings and filter/strainer box) so time to remove them and decide which option to take later. Clean them, get them serviced or replace them.

A quick look online injectors £100.93 +vat +p&p each, no change out of £500. Buy a cleaner/tester £300 - £500 or get them serviced at £12 - £25 each. tbc

46

Time to go back to the beginning maybe.
Check fuel pressure - don’t confuse pressure and flow. With a duff fuel pump, you can pump fuel out of the tank into an open collector no problems, but as soon as you load the pump against the regulator to build pressure it can’t do it. I would suspect some fuel if it had less pressure, just not a lot. If you haven’t got a fuel pressure tester, remove the return pipe and see what comes out. If nothing, then you’re not getting enough pressure, as the regulator is never getting to it’s release point.
You can normally hear/feel the injectors clicking when they are energized. You can test this either cranking or with a good live and earth - don’t hold them constantly open, as they don’t like that! Give one a good live, and touch an earth on/off the same as an ECU would, while holding the body and you should feel a click to tell if the solenoid is working. They could still have a stuck valve inside. I have seen something, on a non Lotus, that had been stood and the injectors were stuck shut. They got someone to crank the engine over, while they tapped the injectors with a hammer/punch, and the engine fired into life one cylinder at a time after a couple of taps. If you are feeling really brave, I have pulled the fuel rail and injectors out of the manifold, held the rail and injectors into the rail, and had someone crank the engine over to look at the spray pattern. Be very careful if you go this route!
If you are getting intermittent coil/injector signals with the modified CPS, swap one of the non modified ones back in. If you go back to no signals at the coil/injectors and rev counter doesn’t show engine speed, you have a pretty good idea that the ECU isn’t happy with the crank speed signals.
Shame you’re not closer! Doing this remotely is quite challenging!

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Apologies for the delay and the length of my reply, I wrote it over several days.

Back to basics. Seems I’m back to the start again.

Both the fuel injectors and ignition pack not working. Again the Fuel pump/Injector relay is not being energised after initial ignition reset process completed. I’m back to the CPS sensor signal voltage. Will measure the output again, but nothing has changed? Will also run another set of diagnostics.

I don’t think the fuel pump is the issue. I had disconnected the return line when I put new fuel in to make sure it was both clean & primed. But in for a penny, will place a pressure gauge on order.

One thing on my list to do was the 48 pin plug and connector replacement. Intermittent fault and connectors, experienced this before on one or two ships. So a fun couple of hours with the right release tool for the pins and new connector shells. Checked each pin for damage, documented each wire and socket/plug number carefully, just in case. No obvious issue where it counts so removed from my list. Ran another set of tests for comparison with the last set, all similar so happy with the work.

Well the new pressure gauge kit arrived today and a fuel pump pressure test carried out.

Not the 43.5psi (3bar) expected but a creditable 28psi. Not too bad considering the engine is not running. Alas the gauge kit did not come with a calibration certificate, so the pressure is a ball park figure. Not sure the engine would run sweetly, but even with poor atomisation and penetration the pressure should be good enough to start the engine. It may pick-up when the engine is running.

Good idea of yours to put an independent power supply across the injectors. Did that and found all four injectors hesitant but after a few attempts got the solenoid free. Can hear and feel the solenoids working, don’t get the squeak of the fuel passing through the valve (or is that just diesel injectors?). As you say it don’t prove the valve is working. But it gets another potential problem off the list.

Cranked the engine over and heard a loud bang. A moment of optimism, then realised that is was caused by me exercising the injectors. Not sure which cylinder it was but I’ll take it as a good omen.

Pulled the injectors, complete with fuel rail & pressure regulator, placed them into jars and cranked the engine. As suspected, without the fuel pump/injector relay being energised the injectors won’t work. Oh well it’s now setup to see the spray pattern and quantity of fuel delivered by each injector when they do work. Who needs a £600 injector tester, when you have four jam jars and a fire extinguisher?

NOTE: This is NOT a recognised or recommended practice, a tester and the correct cleaning/testing fluid is better for both testing and a person’s health.

Now the battery has had a night to recover, I cranked the engine over. Not easy to see what’s going on whilst cranking, yes I’m doing this solo. Still after a few turns I took a look in the jars and found a drop of petrol from No 4 injector jar.

Inspired I carried on and managed to position the jars and myself so I could crank the engine and see No1 injector. A couple of cranking sessions later it sprang into life. It seems that No2 and No4 injectors did likewise. Shame about No3, not a hint of petrol in the jar.

At this time I’m pleasantly surprised the injectors work, perhaps the ignition coil has also sprung into life also! Time to refit the injectors back into the engine and go for a start. It took a while, seven attempts to be honest, but is was firing on three cylinders. A little throttle and the third injector sprang into life, revs raced up to 5000 rpm.

Tic overs a bit lumpy, but the engines cold, the fuels 7 months old, the airbox and filter need to be fitted, maybe the IACV checked and the injectors serviced. Ah the car that never stops giving.

Time to stop irritating the neighbours, pack up and celebrate with a pint of Tetley tea, also contemplate where I put the ancillaries, auxiliaries, rear and front clams for next week excitement. Tidy up the wiring, pipes and rubbish is order of the day for tomorrow.

So what was the issue? I don’t know for certain. I did punch the end of the CPS in towards the reluctor wheel again this afternoon with a brass drift and plastic headed hammer, not sure what the air gap is now, or the voltage generated. Maybe the 48 pin connector replacement, or refitting all the rear grounds and engine sensor plugs. Who knows but I’m relieved to see it start even if the exhaust wrapping is smoking like a steam train and smelly. Something to look into over the weekend. Will post if it’s of interest.

A big thank you to JDS and to all who offered helpful words of wisdom and support, and those who read my posts.

2 Likes
48

Duly noted and will ignore when mine inevitably fails.

:slight_smile:

Thank you for taking the time to update.

Every single thing you do is of interest to someone in here. I am sure of that.

Even if you try something and it fails its a point that someone else might come across and find it useful in ruling out for them.

49

Congrats. So glad you got there in the end.

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Hi andybond,

Thanks for the support and encouragement.

I may put a list of issues I found preventing the Exige starting, just as a pointer should anyone else have a similar problem after a long lay-up. I have it all documented somewhere.

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Hi thommo,
Thanks for your support, it’s a big relief it’s finally going.

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Thanks Dave, I could not have got the Exige working without your help.

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Well done for the perseverance.

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I think it was John (@JDS) who is at SeriouslyLotus who assisted.

I am sure Dave (@seriouslylotus) was pointing out things too :slight_smile:

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Thank you.

56

Thanks for the info.

I thanked JDS a couple of posts back, didn’t know their names, but thanks again John we got there in the end.

The Dave I was thanking is EXG932 who loaned me his spare ECU and tested my ECU at the start of this thread.

57

Glad you have got there.
I’d get the fuel pressure/tester checked, as a third less is lot to be missing.

58

Thank you. I think your right.

I took a closer look at the manual and found I had misread the fuel line pressure, iaw Lotus Service Notes section EMN page 21 the pressure gauge with engine idling should read 2.9 - 3.1 bar with the vacuum hose disconnected and 2.2 bar attached.

I had 32 psi on the gauge this afternoon with the vacuum hose connected at 1250 rpm which is 2.2 bar.

However tomorrow I will carry out all the tests iaw Lotus Service Notes section EMN page 21 to ensure the system is issue free and the gauge is usable.

59

Just stumbled across this but glad you seem to be on the home stretch! I know how annoying it is to not definitively find the fault, but if the tacho was moving during cranking, it probably wasn’t related to the CPS, as that is driven separately by the ECU.

Electrical fault finding can be pain - I recently took resistance readings at the ECU plug and cross-checked them with wiring diagrams. There were 648 combinations…. :sob:

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Hi C8LGY,

I thought the CPS provided a variable signal to the ECU for both timing and engine revs.

The ECU is solely responsible for the initial rev counter and speedo reset which is illustrated by both needles going backwards before returning to zero when the ignition is turned on.

Glad the Exige ECU only uses 41 pins and bulkhead connector 42 pins, not sure how many readings I took from sensors, grounds, connectors & ecu but nowhere near 648.