How will you know when the inlet air temp. sensor is broken??

It's now hot here in Holland and when the boost comes in at 0.5 0.6 bar it's just like the engine won't go, like the fuel cut's off.

When i'm driving in the evening or night it's allot cooler and there isn't any problem and i haven't got the problem last summer.

Is it possible to check the sensor??

My car is a stage 1 saff.

Maybe i need a rs500 cooler


Cheers for answers

 

if you pul the ecu out, when cold with the ignition on yuo shoul dget across pins 11 and 31 about 3 volts dc (with the ecu connected to the loom obviously) or with the ecu disconnected, when cold, 3.75K ohm across the same pins, this valve when increasing in temp (80dgc) should go to 0.3 volts or 380 ohm with the ecu disconnected. you will really need to remove the cover from the multiplug on the ecu to geta multimeter probe onto th pins and get someone to watch what it goes to when on boost.

 

I will do that

Is it a common thing that the act sensor is broken?? And does the discription i gave sounds like a dead act sensor???

Cheers

 

hard to say, if it has failed open circuit or short circuit.

as both the ACt and ECt are NTC sensors (negative temperature coeffiecient - ie the resistance goes down as the temp goes up) if it failed open circuit it would think that the boost temp was low all the time and would never knock back the ignition to limit power, if it failed short circuit, then yes, it could tell the ecu to hold back all the time,

eddited to say,
i have not known a ACT sensor fail on either of my cars, but eh ECT one has yes.

 

Strange thing is when its colder there isn't a problem just when it's hot outside.
So i think when its hot the sensor is telling faulty things to the ECU.

When it failed short circuit, then the ECU must hold back any time or not??

Is it possible that other sensors causes this problem?
I can't think of another sensor that can knock back the ignition, only when its hot not when its cold.

cheers

 

could just be overboost, but this usally happens when its been set up on a warm day then you go out on a cold damp morning and "bang" "pop" overboost,

you say stg1, boost should be no more than 1 bar peak, dropping back to just under 1 bar.

other thing to check of course is plug gaps, as they do open up with age and with hotter ambient temp they could be breaking down when she comes on boost. i'd whip them out and check the gaps

 

It's not overboost, on this hot day i haven't got 1 bar peakboost maybe 0.8 when i'm lucky

So i think that i have a faulty act sensor or it's just to damn hot.

What was the plug gap?? 0.8 to 1.0mm??
Plugs are 1,5 year old.


What happens when i disconnect the ACT sensor and take her out for a testdrive??


cheers

 

if you are running a dizzy then plugs depending which they are should be 0.6 - 0.8mm, and if the plugs are over a year old, i would chcnge them as they are faily cheap thing to change, espceially if you go for the 071C at just over £12 a set

 

The plugs that i use are NGK Laser Platinum PFR7B (4853)

Tomorrow i'm gonna check the gap.

thnx for the answers

 

Checked and re-adjusted the gaps, seems like the probleem is gone.
Gap was 0,85mm adjusted to 0,7mm.

cheers

 

 

Thanx again m8

 

problem still there, it's alot hotter then yesterday, i'm gonna check the ACT sensor and maybe replace the sensor.

 

I checked the ACT sensor, just a quick test, it disconnect the connector thats on the ACT sensor, plug a multi meter on and i checked the resistance but no resistance,
It's like the sensor is broken, but then i checked it on my brothers car and also no resistance, and my brothers car is also a 2wd saff but he hasn't got the problem.


The problem only shows up when it's hot outside and when the boost comes in.

What else beside the ACT sensor could it be?? MAP sensor??, maybe the iginition amplifier??

 

 

I've got a similar problem with my Cossie managed RS Turbo.

I've replaced nearly everything on the ignition side of things as it starts misfiring when it's warm (fine when the engine's cold).

It gets worse when I try and hit boost as well. The next thing I'm about to try is wiring up a independent earthing wire for the ignition amplifier. Apparently they benefit from having their own shorter one direct to the car's chassis.

Will let yo know if it works or not as I'm doing that over this weekend!

Cheers,

Andy

 

Maybe the sensor has 'MarijnReuvers' syndrome and it takes YEARS to respond...


MAP-sensor tends to overfuel when fucked so probably it's not that, no point measuring the sensor by itself: measure over the pins in the multiplug that connects to the ECU.

Boostgauge hose might have gone soft and could be leaking air so boost could actually be higher than 0.5 - 0.6 bar although you should feel it cutting the ignition when the boost spikes.

Mind you: airchargetemps will be VERY VERY HIGH as ambients are 35-ish...try on the motorway and see if it's get's significantly better when there's enough airflow over the IC.

 

I drove yesterday +- 20 min. on the highway, wouldn't work, problem still there.
The hoses of the MAP sensor and boostgauge are ok. I checked them yesterday.

Tomorrow i'm gonna change the MAP sensor, measure and maybe change the ACT sensor, and i think i'm gonna change the noisy fuelpump.

This morning i drove to my work and there's no problem, boost peak's at 0.9bar, no misfire, no shaking or cut back.
At 16:00h i drove back and there's the problem, when the turbo is coming on at 0.2 bar the engine shakes and is knocking back and it doesn't go any further than max 0.4 to 0.5 bar.

When it has the special syndrome, i'm gonna sell the car

 

silly question - but have you tried changing the plugs? stick a set of motorcraft 071's in there with a 0.65mm gap - 99% sure its the plugs at fault here.....

 

Do you have a partnumber of those plugs??
Ford dealer in Holland doesn't know the 071 plugs

 

AGPR 071C is the plug part number,

i aint got a finis code tho

 

Ah, with the last description it became clear: ignition or fuel problem!

Ditch the plugs ASAP: when the engine starts rocking and it won't boost it's dropping onto 3 cyllinders! Interestingly that's what my first cossie did before it melted a piston! Check plugs and injector: maybe one of the injectors is blocked!

If it does have the syndrome you shouldn't sell it: you should push it in the river...

 

It's not dropping onto 3 cilinders.
The plugs look ok to me, 2 days earlyer I re-adjusted them to 0.7mm.

If one of the injectors is blocked, the engine should always knock back, atleast thats what i think.
Maybe "shaking" wasn't a proper discription, but when it does im shaking in the car

Will change the plugs also tomorrow.

I'll let you know how it go.

ps maybe pushing the car into the water isn't a good idea, blowing it up would be nice to see

 

the plugs may look ok, but if they have a hairline crack then they will arc and not fire properly

 

my injectors played up on and off...check them to be sure I'd say...

 

Change the plugs today, no luck.
Got another set of injectors, tomorrow i'll get them "cleaned" in a "ultrasonic bath"

I thought maybe the ignition amplifier is getting to hot so i dumped it in the fridge also no luck.

I also checked pin 1 and 19 on the ECU, they are not burned.

Also checked the resistance of the ACT sensor and the MAP sensor and there both within factory limits.

 

 

Update,

Replace the ACT sensor, injectors and fuelpump still no luck.

More and more i'm thinking of the MAP sensor.


Advise please??

 

Try to remove youre actuator and see if the wastgate opens and closes without problems. Do this when youre turbo is cold!!

 

It is impossible to check the resistance of a MAP sensor

This is because it is a semiconductor device not a resistive one.

Have to say, most of this sounds like a classic map sensor fault to me

 

not true ruud....i bought them from a ford dealer....

 

mmm very strange, i have a fault finding map from Ford and they describe that you can measure the resistance of the MAP sensor, it must be between 50 and 600 ohm's. (Cosworth fault finding)


@ Wimwerf, i just called a local Ford dealer and they didn't know anything about 071's so i called a big Ford dealer and they knew it so i got the 071 plugs but no difference.

Tommorow i'm gonna change the MAP sensor, and i hope that the problem is gone then.