High CO / Poor hot starting

[Danevansgolf]

Those injectors are perfect. I received some a few weeks back. They are slightly shorter, but that doesn't matter.. When I changed mine, I took off the rocker/cam cover to make life a hell of a lot easier. Doing this makes getting the injectors out and in a very simple job.. The gasket on the cam cover is made of rubber, so is reusable as long as it's not corroded and knackered. They are available from sj sports cars. Enjoy

[GeoffSmith]

Wouldn't an elanscan have caught this?

It would be good to see the fault on a scan.

It would and it would. It probably wouldn't have set an error flag but the MAP output should have been out of the ordinary.

[Danevansgolf]

Sorry all.. It's the mat sensor which has gone. And I've spoken to my mechanic and the elanscan showed up variables in the readings. I've ordered a new mat sensor from sjs. Can't remember the price, but I'll keep you informed on the outcome. Give me a few days.

[GeoffSmith]

That makes a lot more sense but it would still be interesting to see an ES log.

[Danevansgolf]

PROBLEM IS NOW CURED.
Starts on the button, even when hot. And the lumpy driving experience has disappeared.
All down to the coils being knackered. Paid a premium for a pair of coils only as I wanted them the day after. So they were £35 each. Shhhh don't tell the wife. My mechanic says the car (Lola) drives beautiful and is like new and that I will sh*t my pants. Sounds good. MOT tomorrow and get to test drive in a few days time. Good luck everyone.

[Artaban]

I will sh*t my pants

Hope thats down to the cars performance and not his exorbitant bill for the work which you'll need to explain to the wife.

[Brit-Car-Nut]

PROBLEM IS NOW CURED.
Starts on the button, even when hot. And the lumpy driving experience has disappeared.
All down to the coils being knackered.

Was the problem the MAT sensor or bad ignition coils?

[Danevansgolf]

Ha ha ha ha ha ha ha.
That's all I can say. NOT!,!!!!!,
Back to square one again. Car ran beautiful the other day, once the coils had been replaced and the mat sensor changed.. 3 days later, mechanic checks it all over and the car is back to how it was??? Arrggghhhh. Will update with the next port of call? Running out of ideas. Any suggestions
Hesitation and retarding of engine when throttle is open?
Takes ages to start when engine s warm or hot?

[Brit-Car-Nut]

The AS4 which I ordered via PeterD's posting (NO BLAME INTENDED - he posted that his ended up not fitting either but I had already ordered mine) DOES NOT Fit. Unfortunately, I will have to order a different one because the one I got was not boxed or otherwise marked, so maybe the seller was shipping the wrong part.
I have ordered an AS5 and will go to NAPA when it arrives to see if they have the plug for either and check them that way.

[Brit-Car-Nut]

It gets more complicated.

The Standard AS4 that I ordered from a seller on eBay is apparently NOT an AS4.

The REAL AS4 has two notches that make sure you insert the plug correctly and having looked at a VERY EXPENSIVE AS4, I see that my previously purchased sensor is nothing like the real deal.

By looking at the plug on the M100, I believe the one I just looked at is correct, but I won't know until I get one in hand to actually try the M100 plug. (I could be upside-down in my observations).

AS4b.jpg

It should get here around this time next week so I will be able to plug it in.

FYI, the different plug notches are needed because even though they are all 2Bar sensors, different car manufacturers demanded different connections and the only way to make sure you have the right sensor is if the plug slides right in.

I will update this again once the order arrives.

[Brit-Car-Nut]

I finally got a REAL AS4 sensor. That is the Standard Motor Products part number. The GM number is 12569241 and the ACDelco number is 213-1520.

You can tell it is correct if it has an orange mask inside the plug socket.

The plug fits correctly and the car runs as normal.

I also got an AS5 because that is also listed but that is the one for the NA M100 or Geo Storm or Isuzu Impulse non-turbo. It doesn't have any plug notches and it will plug up but it is only a 1 BAR sensor, so the ECM doesn't like the output it gets when running so it stumbles.

My previous picture is the correct item.

I am trying to work out a decent price through an obsolescence company I have used previously. I really don't want to pay $50.00 or more for a MAP Sensor. I will let everyone know what I can arrange and the price I can get them to reduce to.

In the meantime, DON'T TRUST all of the cheap sensors on eBay. MOST appear to not be the right item. I bought 3 others from different eBay sellers and none of those had the correct plug socket.

[nhaynes]

OK, here's the fix for my High CO and Poor hot starting which actually manifested into a mis-fire on 1 or 2 cylinders - FUEL INJECTORS!!
I bought a set of Delphi (Rochester) injectors off ebay:
http://www.ebay.co.uk/itm/Set-of-4-BRAN ... SwxCxT9R52
I'd completed several diagnostics before buying the injectors with the help of Pete, another LEC member is Essex. We confirmed the ignition system was ok and also the ECU. Pete brought his Elan around and we swapped ECU's. My ECU in his car was fine so we knew it wasn't my ECU drivers. So we checked resistance across injectors and two were showing low resistance so noW I was almost certain, fuel injectors were the root cause of my problem!
I followed the WikiLEC process for Fuel Injector removal and re-fit. There are 3 small errors on the WikiLEC page: First error, no mention of relieving the fuel pressure before starting. On RHD Elans, the fuel cut off is under the hood stowage, close to the battery. Simply push the fuel cut off switch down and pull back up when you want to re-start. Following the WikiLEC instructions 2. The bolts holding the plastic wire cover are 10mm not 12mm and 6. The 14mm fuel rail bolts are 12mm. I'd already removed the injector harness wire clips (which are a sod of a job), with a metal tooth pick you can buy from a dentist. The next most difficult item is 5. Removing and catching the T26 Torx screw securing the fuel pressure regulator. On re-fit, do be careful not to slice any fuel injector O rings, the clips that hold the injectors in place on the rail are close and I managed to cut one of mine. Annoyingly, I didn't discover this until I'd completed the work and I had a floor of fuel on key on. Also dont remove the injector to rail clips as they are difficult to secure back on the rail. I suspect these clips aren't actually required as the injectors are captive between the cylinder head and fuel rail that are bolted together. I suspect the clips were merely an assembly aid to keep the injector and rail together when assembling in the engine plant. Be careful not to lose the T26 Torx screw on re-assembly of the fuel pressure regulator. Press a bit of blutak into the Torx drive to secure the screw to the socket and carefully start the screw into the thread. I've purchased a extendable magnetic stick which is really useful for catching or finding screws as they fall!
So, a couple of hours later, second start after fixing the fuel leak and everything fired up. Fantastic! No mis-fire at all. I then checked my CO level with a Gunson CO meter. It was running very rich ~8% before, now its <1%. Make sure any CO check is done when the engine is Hot, after the cooling fans have cycled. I then switched off and did a hot start. She started immediately, so the hot start issue is also fixed. I'm feeling rather chuffed now!!!

[John_W]

Well done Neil. I hope that you have fun driving it now.
John

[peteoddcar]

Great News
I will order a set for my car as seems to be an age related failure from what I can gather.
I think they are still available on EBay

[Steve A]

Yesterday I fitted a set of these http://www.ebay.co.uk/itm/Set-of-4-BRAN ... SwxCxT9R52
mainly because my car doesn't like starting when it's warm or even after I've been to an event and it's time to leave an your surrounded by "other Lotus "owners and your willing yours to start but it takes just long enough for people to start looking before it bursts into life
Anyway so after reading nhaynes postings I'd convinced myself this was the way to go
Using the wiki and nhaynes tips (BTW it's a T30 Torx screw securing the fuel pressure regulator )
Not the easiest task typically Lotus awkward I'd say but fairly straight forward if you like putting ships in bottles that is.
As mentioned before these injectors are slightly shorter but as others have used them with success I thought it was worth a shot,(it's just typical that there seems to be quite a few up for sale recently )
After I fitted the injectors it started on he button (but it always did if left over night), I checked for any leaks, none.
So I intended to take it round the block and give it another check but the sun was out and I just didn't want to stop as you do
One thing I noticed that seems different, it really pops when I'm off the throttle, it did a bit before but it seems much more pronounced ?
The injectors are described as upgraded would this make a difference ?

Thoughts

[Giniw]

Have you reset your ECU? It might make a difference if it had learned odd corrections? (not sure if it corrects anything with an open loop though?)

[Simon_P]

The injectors are described as upgraded would this make a difference ?

Yes, they are cheap injectors upgraded to expensive ones. So the seller won't be able to answer your questions!

[Steve A]

The injectors are described as upgraded would this make a difference ?

Yes, they are cheap injectors upgraded to expensive ones. So the seller won't be able to answer your questions!

what makes you say that?

[Steve A]

Have you reset your ECU? It might make a difference if it had learned odd corrections? (not sure if it corrects anything with an open loop though?)

To be honest it didn't occur to me to do so, if the ECU runs with the standard injectors how will it know or calibrate (if that's the right word) to the new ones ?

Before I changed the injectors the car was running rich and the exhaust was also quite sooty leaving deposits around the bumper which wasn't a recent thing I didn't know if it was related to the hot starting problem.
After my long drive yesterday I left it for an hour and it started on the button

[Giniw]

I think when the car is using a lambda sensor in closed loop the ECU may adjust a bit the fuel quantity it asks the injectors to ... inject in the engine to obtain a proper air/fuel ratio. Of course the ECU may adjust it in near realtime (=short term adjustment) but I believe it also has a long term correction factor so it affects the base command sent to the injectors even before the lambda live correction.
That is something I would try myself, I am not sure of anything. In any case, that probably won't be worse if you try I think.