Outer Limits 4x4 Board

Anyone got any suggestions on what could be causing an engine hesitation on cold mornings? Usually happens after changing into second- put the foot down and the engine just doesn't want to accelerate for a couple of seconds.

The distributor cap is reasonably new, as are the spark plugs, and I fitted new Magnecore leads on the weekend with no improvement ... I'm beginning to suspect the distributor advance mechanism?

How clean are your injectors... mine did this on my old engine, got em cleaned and stopped doing it.

Injectors were cleaned about 12-15mths ago and I run it almost exclusively on BP Ultimate 98.

I've read about engine earthing problems causing similar dramas before- does anyone know the locations of the earthing points for the engine? Most vehicles seem to have a big mother strap somewhere from the engine to the chassis, but the Feroza doesn't seem to?

There's a small one from the inlet manifold to the firewall; plus all the EFI loom earths are bolted onto the head bolts for the inlet manifold and then disappear into the EFI loom heading somewhere?

you should also have an engine to chassis ground as well... see if you can source it by following the wires off of your neg. battery terminal. might help to clean it out. i had that same issue for a while.

SimplyPV wrote:you should also have an engine to chassis ground as well... see if you can source it by following the wires off of your neg. battery terminal. might help to clean it out. i had that same issue for a while.

Any idea where it bolts onto the engine? I was assuming the wires from the battery -ve were just going to the starter motor/ alternator from the direction the loom heads off in??

david.. it should lead off of your neg. battery terminal to the chassis somewhere. mine hooks onto a bolt thats part of the engine/chassis mount. there should be another earth ground leading off of the neg. battery terminal that hooks onto the body, prolly right next to the battery platform on the inside wall of the fender. theres also another one but i think it hooks onto the intake body from the efi loom... cant be positive about it though.

Check here for an update on the problem:

http://www.outerlimits4x4.com/PHP_Modul ... 405#304405

(posted this for anyone searching in the future )

hesitation when cold.... shrinkage?? hehehe




sorry dave, couldn't help myself besides, the diahatsu section's gone pretty quiet since a few of you have defected

stumped wrote:hesitation when cold.... shrinkage?? hehehe

Cold weather will do that to a bloke....... but I was talking about the Feroza.

It was surging too, but I'm glad I didn't put that in!

murcod wrote:

stumped wrote:hesitation when cold.... shrinkage?? hehehe

Cold weather will do that to a bloke....... but I was talking about the Feroza.

It was surging too, but I'm glad I didn't put that in!

hehe

Did some light reading of the manual a while back and I seem to recall something saying that the ECU does not actually start managing the engine until optimal engine temp (around 400C) is reached...

Mine hesitates like that as well..and with mornings down to around -4C here some days it still does it if the engine is cool and its 25 outside...

As soon as the temp guage is up...it goes away...

Doesn't bother me too much...I'm not here for quick starts

mine does the same thing on occasion.....have tried fuel injection cleaners to no avail. Only happens once in a blue moon so it's not really an issue for me.

doesnt take long for it to warm up either and then the problem dissapears. I guess you have to ask yourself if it's really worth worrying bout????

Mine was really bad to the point it was dangerous- eg. change into second, go to accelerate and nothing happened for a second or two! Not good when you're trying to merge or pulling out in front of someone....

It was worse when cold, but there all the time. A hill I drive up everday I could feel it start to accelerate after I'd back off the throttle (!?); and then continue to subtley surge up the hill on a constant throttle. It wasn't noticeable before the extractors as the oxy sensor wasn't operating at all due to the old manifold somehow not being earthed to the engine (ie it was never trying to go into closed loop before!)

It's a lot better now and has more pick up in any gear at partial throttle openings and my fuel economy should improve too.

What Murray said is right about ~400 degrees- but that's the temp the oxy sensor needs to get to before it start to generate a usable voltage. When I was monitoring the output voltage on mine it only took a couple of km driving before I could see the voltage varying around 450mV indicating it was in closed loop and being used to control the mixtures.

I was also surprised how much time it was actually in closed loop mode. I was always under the impression that unless you were gently accelerating or decelerating then you were not using the oxy sensor output. In fact it's being used most of the time and only appears not to be when the throttle is fully open or fully closed.

I'll write a bit more on how to check the oxy sensor when I've got more time, plus some ways to test them.

It appears my detonation problems have gone now too; but will have to wait until the weather warms up to be sure.

well i hope mine doesnt get as bad as yours was.

had a very similar drama that i put down to a crappy batch of fuel...lastest a while then seem to go away.

on our last trip i drowned my uni filter which i replaced with the old paper one. i noticed a decrease in power and take off straight away.

so with all the above issues, it's hard to say it i have a similar problem to yours.

It only took me 20 months to find the fault with mine. There's been something wrong since the first day I bought it- needless to say I'm happy it's finally fixed.

(I have learnt a lot along the way too. )