Hesitation under load, ECU?

[M3CHA-MONK3Y]

Hello fellow S owners,
Having stripped the car down over the past few months, we're now back together and have been up and down the road for a test spin. It's generally running nice except it seems to hesitate under load. Revving on idle is perfect, but cruising down the road and applying a bit of throttle, it moves but coughs and spits a little.
I thought it could be fuel pressure or a dirty fuel filter but somebody mentioned another alternative. Correct me if this is complete crap but the S comes equipped with a learning ECU? So if I've had the car without juice for a few months, the ECU will have reset to default settings, which seems to be the same settings as a Morris Marina.
Does anyone have any experience with this after a rebuild and roughly how long does it take to adjust. I don't want to drive like a little old lady, only for it to adopt that as standard driving practice!

Cheers guys

[Barkychoc]

TVRGIT is the expert but it has to go through a couple of warm up / cool down cycles I think before it settles down.

[Wiz]

Mine ran pretty bad after having the battery off for a while second time i went out it was fine. Put it down to the ecu.

[mep12345]

Barkychoc said:

TVRGIT is the expert but it has to go through a couple of warm up / cool down cycles I think before it settles down.

same with mine after rebuild - the fan has to cut in AND out though, stop halfway through the cycle and from my experience you have to do it all again

[bil]

My ECU (ECC IV, 88BB type) the pin 1 KAM (keep alive memory) or KAPWR (keep alive power) doesnt contain a pin i.e. isnt live, ive interperted this as the ECU may well be self adapting to the current conditions, it can't be self learning as no memory is stored. you could also argue that self learning isnt useful as its only the current conditions the engine will find relevant. the annoying point of not having an a memeory is that no fault codes are stored if you turn the ignition to off.

bil

[tvrgit]

mep12345 said:

Barkychoc said:

TVRGIT is the expert but it has to go through a couple of warm up / cool down cycles I think before it settles down.

same with mine after rebuild - the fan has to cut in AND out though, stop halfway through the cycle and from my experience you have to do it all again

I found through trial and error (more by error than trial to be honest) that if you disconnect the bsttery (or if it goes really flat) the car runs terribly, idle speed is all over the place etc. I happened to leave it running one day and the fan cut in, then off again. Next time I used the car (to go home again) it was fine.

I was having trouble with something else (can't remember what it was) but was disconnecting the battery a lot at that time. Next time, I tried the cold-hot-cold cycle and again it worked. It's as if it has to learn how far apart "cold" and "hot" are so that it "knows" when to add cold-start fuelling and adjust the air bleed to get a higher idle speed.

bil said:

My ECU (ECC IV, 88BB type) the pin 1 KAM (keep alive memory) or KAPWR (keep alive power) doesnt contain a pin i.e. isnt live, ive interperted this as the ECU may well be self adapting to the current conditions, it can't be self learning as no memory is stored. you could also argue that self learning isnt useful as its only the current conditions the engine will find relevant. the annoying point of not having an a memeory is that no fault codes are stored if you turn the ignition to off.

bil

I was reading a book on Engine Management Systems more recently and it said that most ECUs are adaptive, ie they do "learn" as they go. That's not the same as KAM for fault codes - the early Ford EEC IV ecus never had KAM anyway, you could only read current codes, it was only the later EEC IVs or perhaps the V in the Scorpio etc (94-on IIRC) that let you read intermittent stored codes.

Not sure how that relates to pin 1 "Keep Alive Power" - never looked that up - but I do know that on mine, there is definitely a learning process the first time you reconnect the battery.

[mep12345]

If you read the haynes manual on the Ford ECU as used in the S1-S4 (for Cologne 2.8, 2.9 and 2.9C) it implies there are two types, one with a keep alive memory (KAM) and one without (IIRC the 2.8 and some very early 2.9s do not have KAM). Mine (1992 2.9 without Cat) certainly has the KAM and the readout of faults is 3 digit. I believe the one without KAM is 2 digit fault code output only.

This is just my understanding so I stand by to be contradicted.

Mark

[Jed-S]

bil said:

My ECU (ECC IV, 88BB type) the pin 1 KAM (keep alive memory) or KAPWR (keep alive power) doesnt contain a pin i.e. isnt live, ive interperted this as the ECU may well be self adapting to the current conditions, it can't be self learning as no memory is stored. you could also argue that self learning isnt useful as its only the current conditions the engine will find relevant. the annoying point of not having an a memeory is that no fault codes are stored if you turn the ignition to off.

bil

..also what can the non cat ECU learn from? The S3C has a lambda sensor to create a feedback loop that the ECU can learn from but that isn't present on the non cat engines.

[tvrgit]

mep12345 said:

If you read the haynes manual on the Ford ECU as used in the S1-S4 (for Cologne 2.8, 2.9 and 2.9C) it implies there are two types, one with a keep alive memory (KAM) and one without (IIRC the 2.8 and some very early 2.9s do not have KAM). Mine (1992 2.9 without Cat) certainly has the KAM and the readout of faults is 3 digit. I believe the one without KAM is 2 digit fault code output only.

This is just my understanding so I stand by to be contradicted.

Mark

I think you're quite correct, I just didn't know the year they changed.

[M3CHA-MONK3Y]

:Woooosh:

That's the sound of everything tvrgit, mep1234 and Jed-s have just said going straight over my head

Cheers guys, I understand where we're coming from now. I had run the cold, hot, cold cycle as standard practice anyway and the idle and general running is okay. It just seems to be a bit less sure of itself under acceleration. I'll probably just run it for a few weeks and see how it pans out.
So far though, I think it's either:

1)Partially blocked fuel filter

2)Fuel pressure

Hopefully it's nothing.

Cheers for the help guys

[Gerald-TVR]

Have you replaced the hose from the tank to the fuel pump. It needs to be armoured and hardwall if its just ordinary fuel hose it could be collapsing under suction thus restricting fuel flow. Adrian@ has/is sourcing some replacement hose to original spec

Norman