CEL @ 1500 or less RPM

RichieOzzie · Post by **RichieOzzie** » Sat Mar 04, 2006 11:19 am

Another idea...

There is a RPM sensor on the engine. Has this been bumped at all. Sometimes they are just slightly out ofplace, and they fail at register correctly at lower Revs. and will throw a CEL. Can you red the code out at all?
The memory will have the code in memory.

RichieOzzie · Post by **RichieOzzie** » Sat Mar 04, 2006 11:35 am

And there's more!!

The Hi RPM is bad on idle. the throttle valves are closing all the way? Take the TPS off, disconnect Throttle cable, and back the Adjustment screw way out so it is not in contact with the lever on the valve actuator. Does the B/Fly close completely.
The ECU expects a voltage of about 0.450 Volts at adle, if not it will fight to get satble, econmical Idle, and can Error out.
Is the Idle speed controller connected?

I did manage to get one of my woos to errorwhen I opened up the Butterfly too far at idle. It was fine when in use, but CEL'd at Idle-ish speed.

The way to think is what has any input to the ECU at idle. Only eng temp sensor, MAP Sensor,TPS, Idle Speed controller and RPM sensor. If you lookaround them, and make sure they are intolerance, and stttings are correct, it could be a good start.

The MAP sensor will throw a CEL if the pressure drops too low in the Tube, or feed to it. Is the vacuum line to it ok, and!!!, important... is the vacuum in the Manifold being maintained.... is there a leak anywhere, or a pipe come loose somewhere?!?!, I seen it do this too!!, and it was one of the tubes had a split in it underneath, you take it off, and it looks ok, but give them a "Bending" to see if there is a split, and Make sure they fit snugly as well.

An odd one I have seen is the Brake Vacuum Servo has a leak on its Diaphragm, and when engine idles, the Vaccum cannot be maintained.... and on goes the CEL!!

RichieOzzie · Post by **RichieOzzie** » Sat Mar 04, 2006 11:44 am

And just to finalise!!! (sometimes am a little slow at mornings)

Another is.....

AIR leak in the Manifold. Hi rpm(uncontrolled), CEL(from MAP sensor) = Vacuum leak man.

idle the car, spray relese fluid or something like that about all the gasket areas, if the rpm changes when you do it, there is the leak....!!

Check Vacuum servo, these are often overlooked. Disconnect it, bung the end, and then fire her up. and then make sure all pipes are in the right place.!!!

MMamdouh · Post by **MMamdouh** » Sat Mar 04, 2006 10:10 pm

nice analysis man... will give it a look and keep you updated.

MMamdouh

RichieOzzie · Post by **RichieOzzie** » Sun Mar 05, 2006 6:49 pm

No Worries Mate.

A Friend in need, is......

Post by **PrecisionBoost** » Mon Mar 06, 2006 1:22 am

How about the Knock sensor...... usually it's most sensitive at low RPM..... the ECU would throw a CEL and dump in more fuel as it moves into a "safe mode" to combat the Knock signal.

Did you tighten it onto the block with the correct torque??

I know other guys that have had knock sensor based problems..... sometimes they are a pain to diagnose.... the only way to know is to get the code scanned.

Are you using the 2.0L knock sensor or the 1.6L knock sensor??

MMamdouh · Post by **MMamdouh** » Mon Mar 06, 2006 9:37 am

we are getting the car scaned today as yesterday was a vacations and all shops are closed.

yes we are using the 1.6 knock sensor on the 2.0 and it was working fine for he past 2 months, we didn't torque it correctly as a) we don't know the correct torque and b) no one in this country have a torque wrench to do that.

the car was running perfictly untill we installed a new CAI setup then the CEL came on... the stock intake pipe is now back with the IAT sensor and breather hoses and every thing yet the CEL still comes on at idle... now we have idle speed issues as well so it is getting too complicated to diagnose the problem without scaning it.

i will give you all feedback on what we find.

MMamdouh

RichieOzzie · Post by **RichieOzzie** » Mon Mar 06, 2006 1:34 pm

Hummmmm!.

Knock sensor comes more into play when the car engine is loaded, and I would expect it to "CEL" when being driven.

Not unless the Timing is Waaaaay out, or as you say, it could have been over-torqued at the time of fixing. I would expect the element inside to be cracked completely. But then why at fast idle/idle speed?

But, as with all motor problems.... can sometimes be mis-leading.

Is the ECU the right one for the motor xchange.... and therefore is the wirng loom the same one to go with the motor, or is it the orig one, or could the wiring be slightly different?

Just a thought!

MMamdouh · Post by **MMamdouh** » Mon Mar 06, 2006 2:20 pm

the ECU is the OEM one from the 1.6 DOHC... yes it is not the correct one for the engine but it works fine... we didn't even have a CEL the first time we cranked the engine after we droped it into the car... i am sure it is not ECU comptability issue.

i think it will be a faulty sensor or wiring to a sensor... the question is which or where is the problem, we will know when we scan her today and see what we will do.

MMamdouh

karim · Post by **karim** » Mon Mar 06, 2006 2:31 pm

I thought the ECU is the same of the 2.0 like the 1.6. If you use ECU of the 2.0 will even be better.
I think the CEL problem is wire and sensor issue. Keep us posted.

MMamdouh wrote:the ECU is the OEM one from the 1.6 DOHC... yes it is not the correct one for the engine but it works fine... we didn't even have a CEL the first time we cranked the engine after we droped it into the car... i am sure it is not ECU comptability issue.

i think it will be a faulty sensor or wiring to a sensor... the question is which or where is the problem, we will know when we scan her today and see what we will do.

MMamdouh

Nubira2.2 · Post by **Nubira2.2** » Mon Mar 06, 2006 2:43 pm

Reset ECU

MMamdouh · Post by **MMamdouh** » Mon Mar 06, 2006 2:57 pm

tried that 3 or 4 times.

MMamdouh

MMamdouh · Post by **MMamdouh** » Mon Mar 06, 2006 7:52 pm

it was the damn TPS indeed... the old one was a toast so we got a used one for testing and the high and flicking idle is now gone, apparently the CEL was due to the fact that we messed with the TB screw and it wasset too hig than normal so the CEL is gone as well.

if one thing we learn from this setuation that will be "never try all your ideas at the same time, try them one by one"

MMamdouh

Post by **PrecisionBoost** » Mon Mar 06, 2006 8:04 pm

RichieOzzie wrote:Knock sensor comes more into play when the car engine is loaded, and I would expect it to "CEL" when being driven.

Not unless the Timing is Waaaaay out, or as you say, it could have been over-torqued at the time of fixing. I would expect the element inside to be cracked completely. But then why at fast idle/idle speed?

Ya... it was just a stab in the dark... most of the other posibilities were allready covered....I wasn't saying the engine was knocking.... I just thought perhaps it could have been installed incorrectly...... I wasn't thinking over torqued.... I was thinking hand tight and vibrating at idle.

I was thinking the engine would throw fuel at the problem.... which would make the idle speed erratic.

Anyways.... like I said... most of the other posibilities were allready covered.

Glad to here the car is up and running smoothly again.

RichieOzzie · Post by **RichieOzzie** » Mon Mar 06, 2006 10:42 pm

Yep, You are right there Chris. I suppose we did cover "all bases", apart from the odd ones you would never even consider would give a problem.
I have to admit, the knock sensor, or any other obscure ones could have been to fault..... Guess we have both seen some wierd ones in our time? ..... AND I was waiting for the feedback to show this too!!, 'cos you never know really!

It is the Spirit of this forum, where we all dive in to help.... It is good to see it happening. I think everyone needs congratulations, because we all fixed the problem in a round-about way. although we wern't at the "sharp end" of it.

Good to see problem solved. Well done Mohamed. ........ All them heads under one Car hood at the same time eh!

Maybe we should create our own "Book of Answers" one day, like a "sort of" flow chart.... It could sell via CD to "Mr average Woo owner". Anyone else ever seen the Ford TEC C.D.?

I think I wrote something about this TPS adjustment in another thread...... I have found it can really mess things up if it goes Squiffy, or you get to "mess" with it.

Real Data on setting it up is VEEEERY hard to come by nowadays. I did some extensive scratching about for anything about it, but the end product was always dependant upon your own Engine in particular.

I have found mine to need setting to 0.447volts to make the car "liveable" in all conditions. The lower the Voltage, the slightly richer the mixture, but too low, and "CEL", and conversely, the other way as well.
I also know that if you are monitoring the voltage, and engage the Air-con, the voltage drops by 0.025volts, seems a good ref figure to use.

AND the TPS, as we now have proved, does in fact go Squiffy, and according to inside information, more often than we think!! BUT you don't notice at W.O.T (Wide Open Throttle) useage, you just think it is a "Gut-less" car, and give it more "Boot".

I am still considering writing it in here, the way I found that it works, even though I saw a chart about it, the figures given were too broadly given. The figure used is more precise in practice.

What does the "Collective" think?

The original daewootech forum

CEL @ 1500 or less RPM

FIXED!