Urgent help please

J

Jonny_gti-r

Guest
Hi guys,

had my gti-r for about 6 weeks now and its started giving me some trouble. when the engine is upto regular running temp it has started running really badly (feels like it has a missfire) you put your foot down and it feels to be holding back or can't go..... i had it on the rolling road and the told me the knock sensor is registering a fault and this could cause it to run in limp mode or something...... i'm no mechanic so i don't have a clue!!!!

Does anyone know about this or had it happen to there car? i'd really appreciate any help anyone could offer

cheers jon
 
A

AJ4

Guest
Hi Jon,

Its a very common problem, the det sensor is prone to breaking and lots of people have the same problem.

If you can confirm definately that the det sensor is broken ( and not just measuring det ), then the only solution is to replace it. Unfortunately its a pain in the ass to do yourself as it hides way up the back of the block...
 
Fast Guy

Fast Guy

Moderators
Staff member
Have you done an ecu fault check to confirm it is the det sensor code coming up?
If the det sensor is doing it's job, it should let the ecu cut boost and retard the ignition timing. It shouldn't run badly. That's not to say the det sensor couldn't be faulty tho.
Also worth checking are your plugs (condition and gap), AFM may be playing up (need regrounding maybe), You may have a boost leak somewhere, fuel pump could be starting to play up, coolant sensor faulty (there's 2 of them I believe) and maybe a few other things :?


When was it last serviced? If you don't know, it may be worth changing the plugs/leads/rotor arm/filters etc
 
J

Jonny_gti-r

Guest
Well the car was serviced just before i picked it up, new plugs leads and the like.... the guys at the rolling road did some code checks and it was coming up with a code 34????? the car has also been taking the pi$$ with fuel too, i was using about £40 a week until recently and now that only seems to last a few days!!!!!

It actually only pulled 154 bhp on the rollers and the guys there were saying it was very flat..... i'm concerned that it could be an expensive garage bill and i want to make sure i don't get ripped off for work that doesn't need doing!!!!
 
Fast Guy

Fast Guy

Moderators
Staff member
If it's using alot of fuel, check your afm, they often need regrounding, your coolant sensor, it may be telling the ecu the engine is cold so permanently over fuelling, or the Lambda sensor may need replacing.,

The det sensor is possibly faulty or the wire to it has broken off.

154 at the wheels or at the fly? If it's at the wheels, it's down abit but not too much. (about 14bhp?) :wink:
 
daz

daz

New Member
yes but also when the det sensor is fucked the ecu cuts boost retards timing and over fuels the car had this when mine was playing up but as fast guy said wouldnt really make it run shit. so i would change the det sensor 1st and then drive it and do another fault code check see what you get
 
daz

daz

New Member
because the other thing mine was using shit loads of fuel i took the afm out and found that one of the bars was dirty cleaned it with carb cleaner and its alot better now
 
J

Jonny_gti-r

Guest
Thanks for your comments!
Not to sound thick or owt but whats an afm?
 
A

AJ4

Guest
it measures how much air is going into the engine so it knows how much fuel to supply at each rpm. Its next to the air filter, little round tube with a connector on it.
 
J

Jonny_gti-r

Guest
urgent help please - update

so the car has been to Richard Henry Motorsport (a place i won't recommend but that's another story) The knock sensor is fooked and so is the lamda sensor, Car is in Nissan dealership now being done.

Hopefully it will be back up and running later today
 
J

Jonny_gti-r

Guest
Urgent Help please - Update

£600 later and the cars off to the rolling road this afternoon to see if we can sort it once and for all. Car seems to be a lot better than it was but still feels a little sluggish so hopefully this rolling road session will uncover any other problems.

Jon
 
J

Jonny_gti-r

Guest
Well we are upto 172bhp from 153 last week, turns out my boost control solenoid isn't getting a pulsed earth? therefore it doesn't boost properly..... anyone got any knowledge on this???

Any help greatly appreciated

Cheers

Jon
 
Fast Guy

Fast Guy

Moderators
Staff member
I don't know alot about it, but the boost solenoid gives you the extra 2psi (I think) over what you get in safe mode. So if it isn't earthing and your loosing boost, it might be worth making sure it isn't the ecu doing it's job :wink:
Not sure why it would be a pulsed earth, asuming that is what it sounds like it should be :?

Was your car running well, or has it always been like this?
 
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