Loss of power/Rough running when Turbo....

[NIL8379]

cuts in.

Problems again. Just got car back on road after a long lay off since last sumer.

Had to fit a new ECU since last on the road. Now having the chance to really test the car I find it has a fault when driven hard.

You wouldn't know anything was wrong unless you bring the turbo into play. Car initialy pulls well then as the gauge get to about .25 power is cut and engine is a rough as a bears a**e! Immediatly you back off the throttle all is well again.

No fault codes logged!

Any ideas?

Steve.

[M100 TWO]

plugs is the cheaper option to go for first, then plug leads but I expect all along it is the coil braking down under load
john

[NIL8379]

Interesting John, I did suspect the plugs and put a new set in yesterday but no difference. Have you had a coil go? If so are the symptoms as I have described them? Is there an easy way of proving that it is the coils breaking down. There's no fault with the engine when the throttle is wide open in any gear, only when the turbo kicks in........

Still puzzled as to why there's no fault codes from the paper-clip test????

Would I expect to see a fault code if it was the coil/leads problem?

Steve.

[timmo]

maybe a sticky wastegate

[M100 TWO]

Steve yes I have had a coil go this year, it does not bring up any codes and it is how you describe your problem the only way to prove it is to change the coil pack

[John_W]

Still puzzled as to why there's no fault codes from the paper-clip test????
Would I expect to see a fault code if it was the coil/leads problem?
Steve.

Steve,
Only expect fault codes from the ECU if it gets unexpected readings from its sensors. ECU fault codes don't pick up everything, nor are they meant to.

Did you gap the new plugs correctly at 31 thou? If that is OK, check the leads on a dark night with the bonnet open, or suspect the coil pack.

Do you know which cylinders are misfiring? If so it could tell you which coil to change.

John

[NIL8379]

Thanx John, timmo and John W for your input.

Yes, I did gap the new plugs at 31 thou and have been doing a bit of experimenting with the gap to try and prove that it's the coil.

Set all 4 plug gaps to 20 thou and road tested car. Much improved, the misfire only happened once when the turbo gauge got to 0.75.

Just been out again and can't get it to misfire at all.

The tickover isn't happy with the plug gaps at 20 thou, I'm going to open No 2 and 3 cylinders to 31 thou as I think it's the coil that drives plugs 1 and 4 that is playing up. This is from looking at the colour of the plugs after running the car.

If it still runs ok with 2 and 3 at 31 thou I'll open up 1 and 4 to 25 thou, this may give me some reasonable performance till I get a new coil pack.

Still not ruled out the leads.

Anyone got the very cheapest price for a coil pack and set of leads?

Best ive got so far is £80 leads and £92 coil S J Sports cars.
Waiting reply from 24/7 Isuzu spares.

Finally, is there a reliable way of testing these coils/leads???

[stevieg8571]

Hi,
I had the same symptoms with my car at the end of last year(there's a write-up about it in the ignition section).
The unwillingness to really accelerate got progressively worse until one Sunday afternoon it'd idle fine, but wouldn't leave the garage!!
It also turned out to be the coil for plugs 1 & 4 that was the problem.
I managed to get an MSD pack sent from the US after hearing the Lotus ones were hard to obtain. I also changed the leads for less than £20, they're a SAAB item according to the invoice.

Steve

[NIL8379]

Cheers stevieg8571, could you give me the Saab part number as I think it would be a good idea to eliminate the leads if it's only going to cost me less than £20.

Also could you say what the total cost was for the coil please?

I've not identified which coil is a fault yet, I think it hasn't broken down sufficiently to show it's self under normal running/tickover etc.

Thanx, Steve.

[stevieg8571]

Hi,
I got the leads from a motor factors here in Preston. Although I asked for Lotus elan leads, the invoice states 'OEF571 SAAB LEAD SET'
They're the correct lenght/fitment so I'm assuming that's what they have them as in they're applications book. Cost me £17.73 inc VAT!!
GM owned Lotus and SAAB at the time of the elan's design so maybe that's where they origanted from?
As to finding which, if any coil's broken, I unplugged each lead 1 at a time to see how it ran. I noticed that unplugging 1 & 4s leads made no different at all, which pointed to that particular coil.
I think they're $42 each, but maybe there's tax and def delivery (if you can find somewhere that will) on top of that. I got a friend out there to get them for me, and she did it all for free

Hope this helps.

[NIL8379]

Thanx stevieg8571 for that info.

Have tried removing plug leads in turn but there is a significant difference in tickover when each lead in turn is removed therefore not being able to say which coil is faulty, (if it is indeed a coil).

Have also read the interesting thread under the ignition section.

Steve.

[Enright]

OK this is a wierd one:
I've recently developed a bad misfire when I accelerate hard.
I've put new leads on, tried a different set of plugs that were previously OK, swapped coil packs for another old set (which I also thought were OK), all to no avail.
I've got no fault codes, and it doesn't matter whether I'm in open or closed-loop mode (so I can rule out O2 sensor and CO potentiometer).
Unfortunately a wire has broken on my Elanscan lead so I can't post a log.
Timing has been checked and is fine.

1st question: has anybody got any ideas? I could try swapping the individual coil packs over to see if I have one bad and one good in each pack.

2nd question: would anyone in the US be prepared to act as a receiving/forwarding address for a set of MSD coils? Nowhere in the UK seems to sell them, and some of the US eBay sellers want to charge - get this - $136 for shipping of a $46 part!!!

[Monty]

Neil,

Could it be a faulty HALL?

Don`t forget you can get cheap coils from Rockautos

[Enright]

Aha, progress.

Thanks for the reply Monty, but I don't think it's the hall. I already replaced that a while back. I'll check out Rockauto for coil packs, good tip.

I've repaired my Elanscan cable, (finally) worked out the correct COM port, and got a log file.

And it looks like I might have been wrong about the lack of fault codes. The "EST monitor error" flag had one registered already.

I started monitoring it from cold until the fans cycled twice, then went round the block. In every gear it coughed and spluttered while accelerating, so I aborted the run and came back.

I'm hoping that out of the two sets of coil packs I have, half of them work. So I'm going to try a bit of mixing and matching to see if I can improve the situation, then get back online to see if I can order some replacements.

Meanwhile, if anyone can spot anything else wrong with the attached log file (or even confirm my deduction), then that would be great, thanks!

[Enright]

Got it!

The chopping and changing worked - both of the 1&4 packs were on their way out.
So now I'm running 2 x 2&3 packs, and it's working fine.
However if half of my coils have already gone, then the others won't be far behind, so I'd better get ordering some replacements quick!

As a result, my request for help in forwarding a shipment from the US still stands. If anyone has a PayPal account then I can reimburse costs via that so that you're not left out of pocket. Please...?

[paulwatkins]

Don't forget you can get cheap coils from Rockautos

Rock Autos will ship to the UK - and quickly too!

Plus you can get a discount code and get 5% off the list price

[GeoffSmith]

Three days is typical.

Discount code link already on the Wiki!

[WillB]

I get the coils from American Autoparts - 01737-780-888

£ 34.08 + vat each last time I ordered (order code DR39 I think)

[Enright]

Now I'm spoilt for choice!

Great tips all, thanks.