ecu nightmare.

[panic]

My '96 griffith 500 keeps giving me head aches...it runs smoothly for a while then...several malfuntions arise from the shadows

Last time i've changed the distributor, coil, plugs and i did perfectly the timing with the empiric sistem, go fix manually the advance, then go again then refix it, try again until i had a perfect set up.

Good idle, perfect timing, no pinging, fluent acceleration.

Two months later: no idle, strong fuel smell, goes crap at low/mid range, it still goes quick at high range, no pinging but i can feel the engine runs extremely rough and not at full power.

What the is going on? Griffith gremlins attacking my sunny days enjoyment???

I'm on the edge of swapping in a nice 500 cfm carb, would it be a good idea?

[Uncle Fester]

I had a similar problem. It turned out to be a wiring fault in the engine.

Rather than fit carbs, consider replacing the whole lot with a new ECU, coilpack ignition and a dedicated new engine loom.

It can be more economical than trying to fault find the loom.

[GreenV8S]

panic said:

Two months later ... What the is going on?

Things go wrong from time to time. Find somebody who knows how to diagnose this engine management system and get them to fix it.

[trackcar]

GreenV8S said:

panic said:

Two months later ... What the is going on?

Things go wrong from time to time. Find somebody who knows how to diagnose this engine management system and get them to fix it.

I don't know why but that reply really made me chuckle. Hi Peter

[eliot]

Lambda sensors maybe? - I say that because you say its OK at high revs, when i *assume* it goes open loop.

[Happy Jim]

It should run open loop at tickover and WOT, if it's running like a bag of nails across the entire range that would rule out the lambda sensors being the problem. My money is on a shagged MAF.

Jim

[panic]

What aftermarket ecu would you advice here? I have triple carbon intake and all the ancillaries, larger am, decatted sport exhaust, etc etc...

WHAT i do NOT understand is that a few weeks ago the car run like on silk (BTW it never went perfectly on mid range but holded the idle and was still cruisable) and now it goes crap! Isnt this against any illuminism scientific basics? (if conditions remain unchanged the beahaviour keeps unchanged too...)

[hiltonig]

Go Emerald, at least then if you can use a pc you would be able to see whats going on !!

[griffter]

panic said:

Isnt this against any illuminism scientific basics? (if conditions remain unchanged the beahaviour keeps unchanged too...)

Well, yes, so you've probably got an intermittent problem, most likely electrical.
I had similar symptoms. The ignition switch would occasioanally break contact for long enough to corrupt the ecu operation but not long enough to stall the engine. One bank of injectors would open for full pulse duration, so the engine ran fine at max load, high revs but rough and stinking of fuel else where.
Solution was a new ignition switch.

[Slacey]

Happy Jim said:

It should run open loop at tickover and WOT, if it's running like a bag of nails across the entire range that would rule out the lambda sensors being the problem. My money is on a shagged MAF.

Jim

+1

My car ran as described last weekend on the IOM trip, as the AFM was full of water screwing it's readings.

[Johno]

Slacey said:

Happy Jim said:

It should run open loop at tickover and WOT, if it's running like a bag of nails across the entire range that would rule out the lambda sensors being the problem. My money is on a shagged MAF.

Jim

+1

My car ran as described last weekend on the IOM trip, as the AFM was full of water screwing it's readings.

+2

Had this issue when it poured with rain . . . Gave up with standard set up and gone Emerald.

[spend]

If we are needle & haystacking what about barfed injectors?

I think from previous posts Gus is hankering to carb his car, maybe he should bite the bullet?

Dave

[Johno]

Wouldn't barfed injectors tend to indicate a constant issue rather than an intermittent, although perhaps you could tweak the rest of the setting to cope for a while . . .

I'd suffered for a couple of years with the car starting on 6 then getting to 8 after a blip or heating up, in the end I became convinced it was the injectors .. .

Started the car with the Emerald last week with new injectors, and she fired on all 8, no issues.

So depending on age, mileage etc it could be worth getting them checked and cleaned.

[spend]

Johno said:

Wouldn't barfed injectors tend to indicate a constant issue rather than an intermittent, ..

Old & incontinent? Lambda up/down because they are dribbling away?

TBH it could be anything I was mainly pointing out if Gus wants to go carb, there is no reason to dissuade him. Just because your Emeralds are flavour of the month shouldn't affect the freedom of choice. If you look back I think he has been convinced (half?) before to persevere a little longer with Efi.

At the end of the day, if you have lost confidence in something it is prob better to try something else & 'scratch the itch' so to speak whether it is right or wrong IMHO. In the past there have been some quite exceptionally performing carb conversions IIRC.

Dave

[Johno]

Apache's carbed Griffith was a monster . . .

I agree Dave, Emerald's are the flavour of the month (did buy mine a while ago and it gathered dust) . . It is far from the only solution, it just fit's budget wise and interface wise.

I suggest getting hold of a 14cux fault code reader and see what it says. There used to be someone on here renting them for a week at £10 a go, although Italy is a different kettle of fish for postage etc etc . .

That way you can see whether it is an easy fix or an opportunity to go another route . . .

[spend]

Johno said:

Apache's carbed Griffith was a monster . . .

I agree Dave, Emerald's are the flavour of the month (did buy mine a while ago and it gathered dust) . . It is far from the only solution, it just fit's budget wise and interface wise.

I suggest getting hold of a 14cux fault code reader and see what it says. There used to be someone on here renting them for a week at £10 a go, although Italy is a different kettle of fish for postage etc etc . .

That way you can see whether it is an easy fix or an opportunity to go another route . . .

Remember Gus is located in sunnier climes, Emerald probably has less support there than even the Lucas CUSSYAXE!

Dave

[panic]

Johno said:

.........That way you can see whether it is an easy fix or an opportunity to go another route . . .

I think i have another route on my griffith horizon, i've talked to Tim of ACT he'd be glad to exchange my tripple (act) carbon intake with all the efi ancillaries for a nice carbed setup...

Do you think the Holley 500 with its intake will match the same performance level of my efi set up?

[spend]

panic said:

Johno said:

.. i've talked to Tim of ACT he'd be glad to exchange my tripple (act) carbon intake with all the efi ancillaries for a nice carbed setup...

I think I'd be happy to as well I'll even polish the carb & manifold as well

Dave

[panic]

Will the emerald ecu connect directly to the stock bosch ecu connect? what other mods i'd have to fix to run the aftermarket box?

[GreenV8S]

panic said:

WHAT i do NOT understand is that a few weeks ago the car run like on silk (BTW it never went perfectly on mid range but holded the idle and was still cruisable) and now it goes crap!

Things go wrong from time to time, it's frustrating when it happens but it's just one of those things. If you had a good TVR specialist near you it would be no good deal, you could probably just drop the car off one afternoon and pick it up the next morning with the problem fixed. Do you have anyone like that you can turn to, or are you trying to fix it yourself?