Will start but no acceleration

wammers · Feb 5, 2014

Thebest4x4byfar said:
Thought i would have a cuppa and a think went back to the sick rangie and started up whilst running i unplugged the air intake sensor and as expected a different tone to the running engine so tried to rev engine and nowt happened so cleaned sensor terminals with electrical cleaner plugged in and revs now good so went for a short drive and car was driving albeit not the best but driving and picking up speed . Any significance ?

Significant yes. Try cleaning all the sensor terminals see what you get. Maybe a combination of bad signals. Worth a try.

Thebest4x4byfar · Feb 5, 2014

wammers said:
Significant yes. Try cleaning all the sensor terminals see what you get. Maybe a combination of bad signals. Worth a try.

Thanks Wammers
Will give your suggestions a try and yes diags on the way for the future

wammers · Feb 5, 2014

Thebest4x4byfar said:
Thanks Wammers
Will give your suggestions a try and yes diags on the way for the future

You may like to take a look inside the ECU for moisture ingress and contamination. Carefully though.

Thebest4x4byfar · Feb 5, 2014

wammers said:
You may like to take a look inside the ECU for moisture ingress and contamination. Carefully though.

yep i'm up for that and a job i can do in the dry as rain has stopped play, will it do that squid thing and squirt ink at me

Rick-the-Pick · Feb 5, 2014

Don't dive into the inards of the ecu unless you really know what you're doing.

For reference, all edc diesel ecu's will run any P38 diesel, they just need to be programmed correctly.
Your 97 ecu will run the 98 vehicle, & vice versa. You'll need the use of a re-syncer to program it in with.

Datatek · Feb 5, 2014

Rick-the-Pick said:
Don't dive into the inards of the ecu unless you really know what you're doing.

For reference, all edc diesel ecu's will run any P38 diesel, they just need to be programmed correctly.
Your 97 ecu will run the 98 vehicle, & vice versa. You'll need the use of a re-syncer to program it in with.

The early one will not operate the EGR, no problem with that, but nor will it see the air intake temperature on the later MAF equiped engine, so while it may run, it will not run well unless the earlier air intake sensor is fitted in the manifold.

wammers · Feb 5, 2014

Rick-the-Pick said:
Don't dive into the inards of the ecu unless you really know what you're doing.

For reference, all edc diesel ecu's will run any P38 diesel, they just need to be programmed correctly.
Your 97 ecu will run the 98 vehicle, & vice versa. You'll need the use of a re-syncer to program it in with.

I doubt if many people on here will have the equipment required to reprogram an ECU. So if he has a pre EGR car he is better with a pre EGR ECU.

Thebest4x4byfar · Feb 5, 2014

Datatek said:
The early one will not operate the EGR, no problem with that, but nor will it see the air intake temperature on the later MAF equiped engine, so while it may run, it will not run well unless the earlier air intake sensor is fitted in the manifold.

Now i'm confused.com

the air intake sensor is bolted in the bottom of the air intake manifold is the 97 egr or non egr ?

Datatek · Feb 5, 2014

Thebest4x4byfar said:
Now i'm confused.com

the air intake sensor is bolted in the bottom of the air intake manifold is the 97 egr or non egr ?

Yours in non EGR and no MAF. The air intake sensor is part of the MAF on the later EGR equiped engine, not in the manifold.

Thebest4x4byfar · Feb 5, 2014

Datatek said:
Yours in non EGR and no MAF. The air intake sensor is part of the MAF on the later EGR equiped engine, not in the manifold.

ahh cool
sorry for the lack of knowledge on my part

wammers · Feb 5, 2014

Datatek said:
The early one will not operate the EGR, no problem with that, but nor will it see the air intake temperature on the later MAF equiped engine, so while it may run, it will not run well unless the earlier air intake sensor is fitted in the manifold.

Think inlet air temp on the EGR ECU is a preset to force EGR operation. There is no point in reading air temperature at the MAF as it will change dramatically by the time it gets in the manifold via the turbo. Bit like wearing a top coat in Southampton because it's cold in the Glasgow. The MAF measures airflow for the ECU to control EGR we have been through this before. The inlet air temperature never changes on the EGR engine, if the MAF was measuring it it would.

Datatek · Feb 5, 2014

wammers said:
Think inlet air temp on the EGR ECU is a preset to force EGR operation. There is no point in reading air temperature at the MAF as it will change dramatically by the time it gets in the manifold via the turbo. Bit like wearing a top coat in Southampton because it's cold in the Glasgow. The MAF measures airflow for the ECU to control EGR we have been through this before. The inlet air temperature never changes on the EGR engine, if the MAF was measuring it it would.

So you are now saying that the air temperature sensor in the MAF serves no purpose as well? Doesn't know the difference between minus 20 and plus 40C??

Thebest4x4byfar · Feb 5, 2014

wammers said:
Think inlet air temp on the EGR ECU is a preset to force EGR operation. There is no point in reading air temperature at the MAF as it will change dramatically by the time it gets in the manifold via the turbo. Bit like wearing a top coat in Southampton because it's cold in the Glasgow. The MAF measures airflow for the ECU to control EGR we have been through this before. The inlet air temperature never changes on the EGR engine, if the MAF was measuring it it would.

Understood

it's a real learning curve for me and understand that it must be frustrating for the guys on here that know there onions and that's why i'm here to learn

thanks for the continued support also

wammers · Feb 5, 2014

Datatek said:
So you are now saying that the air temperature sensor in the MAF serves no purpose as well? Doesn't know the difference between minus 20 and plus 40C??

Where on diagnostics can you read the MAF defined inlet air temp?

Datatek · Feb 5, 2014

wammers said:
Where on diagnostics can you read the MAF defined inlet air temp?

I'll have to look, but the fact that diagnostics don't report it does not mean it's not used. It's not happy with it disconnected.

wammers · Feb 5, 2014

Datatek said:
I'll have to look, but the fact that diagnostics don't report it does not mean it's not used. It's not happy with it disconnected.

Makes no discernible difference at all to my engines running with MAF disconnected. Other than diagnostics throwing an airflow fault. No inlet air temperature fault ever comes up. Inlet air temp is always at it's constant preset.

Datatek · Feb 5, 2014

wammers said:
Makes no discernible difference at all to my engines running with MAF disconnected. Other than diagnostics throwing an airflow fault. No inlet air temperature fault ever comes up. Inlet air temp is always at it's constant preset.

Hooray, we can all chuck the MAF away

wammers · Feb 5, 2014

Datatek said:
Hooray, we can all chuck the MAF away

If you have disconnected the EGR no reason to keep it.

Datatek · Feb 5, 2014

wammers said:
If you have disconnected the EGR no reason to keep it.

Odd that mine does not run well without it then.

wammers · Feb 5, 2014

Datatek said:
Odd that mine does not run well without it then.

The pre EGR models seem to do ok. But there will be several circuits in the EGR ECU incomplete without the MAF. Fortunately the inlet air temp is not one of them.

Will start but no acceleration

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