MK4 golf 1.6 eratic idling

To me, that suggests a problem with the throttle body, but first check for any leaking hoses.

I'd personally remove it, clean it, refit (with a new seal), do a TBA:

To me, that suggests a problem with the throttle body, but first check for any leaking hoses.

I'd personally remove it, clean it, refit (with a new seal), do a TBA:

That's what the mechanic said he thinks the throttle body needs replacing. But he wanted to see what codes come back on Friday. Sounds like a good start the clean it and align it. Could always be a vac leak rev counter does move up and down between those values above. Hope they have the diagnostic tool needed for an alignment hehe

Thanks for the info.

what happens if you disconnect the maf?

Clean TB til squeaky clean. Re-align with VAGCOM. Check values in live data.

Tim.

what happens if you disconnect the maf?

Disconnected it and it behaves the same ?

Clean TB til squeaky clean. Re-align with VAGCOM. Check values in live data.

Tim.

Ironically thats where the problem started I took the car in to my local used to be trusted garage of 8 years they serviced it and cleaned the TB and now these issues. Took it to them and they had a look and said it was nothing they have done, which is all I asked could it have been caused by the throttle body clean as it was fine before he took offence to this and refused to look at it any further. I explained I'm just trying to find the fault so it can be fixed he feels I have accused him of wrong doing. I asked what he did to the throttle body he said he sprayed lots of carb cleaner down it was clipping the throttle then wiping it clean with a rag.

That said they were supposed to change the HT leads its on 80k on original leads. Makes me wonder what else was not done. Tbh I've used them for years never had an issue but now doubt whether they have done any work to my car over the years given their attitude.

Also once every now and again like every few months I could be driving and come off the gas gas pedal and it jerks and won't rev past 2000rpm. If I turn it off restart it its is ok.

what happens if you disconnect the maf?

Forgot to add he said he sprayed contact cleaner on the maf during the service.

Do you know if they did the TBA after cleaning it?

Do you know if they did the TBA after cleaning it?

The bill lists Throttle body alignment so hopefully they did it.

At the moment I'm guessing its either a damaged throttle body, HT leads or MAF possibly a vac leak too.

Do NOT guess.

Tim.

Do you know if they did the TBA after cleaning it?

New HT lead fitted did not cure it, tba done no change. I'm suspecting the throttle body is damaged somehow. Also have an error code for a power steering pressure switch which can effect idle aparantly its a short to ground more likely a wiring fault than the sensor ? needs a poke I say. Sadly had a quick look at it and noticed that long power steering pipe which that sensor fits in has a weep. So found another job hehe. Sensor is £30 and cheaper than a new throttle body. A google suggest this can cause eratic idle is at fault.

What do you reckon, go for a new pas steering pressure sensor or a throttle body at about £140. My gut says throttle body.

Since you are going to have to replace the pressure sensor anyway do it first since it's the cheapest.

Did you do what the garage suggested, and get the codes re-read?

The PAS sensor short to earth might be historical; it could have been disconnected and touched something when other work was being carried out for example. It would be pointless to replace it if the code hasn't come back, especially as it could equally be a wiring fault.

Chris

Did you do what the garage suggested, and get the codes re-read?

The PAS sensor short to earth might be historical; it could have been disconnected and touched something when other work was being carried out for example. It would be pointless to replace it if the code hasn't come back, especially as it could equally be a wiring fault.

Chris

I did he cleared all codes and re-read them and only two came back.

He said its either a wiring fault or a failed sensor on the pas switch. The second fault he said after inspecting the throttle body and aligning it was the steeper motor is not fucntioning properly. He mentioned if lots of carb cleaner was shot through it, it could have damaged the electrics. Only way around it is a new throttle body which a euro one is about £180 useds ones from partsgateway seem about £60/80

Interestingly the third fault code never returned which was 00533 idle speed regulation, lower stop value. He noted this could also point to a throttle body at fault.

So how would you go about testing wiring on the pressure switch. I do have a multimeter which I have only used to check my battery voltage, but I'm sure its what the tech folks uses for wiring fault finding. I guess that should be my first port of call then if thats ok change the sensor. Then the TB.

I appreciate the help gents, been a niggly problem especially adding I am trying to fit it in between a hectic time meaning I haven't had the opportunity to do much since my poriginal posting and todays posting. Coupled with pouring rain, sods law!

Will it run acceptably with the switch disconnected? If so, clear the code and try it with the switch disconnected. If the code then returns, it's the wiring, not the switch.

Chris

Will it run acceptably with the switch disconnected? If so, clear the code and try it with the switch disconnected. If the code then returns, it's the wiring, not the switch.

Chris

Tried it now, disconnected the switch, behaved fine. reconnected it behaved the same error code came back on. So that points to the wiring. How do i start to find the problem ?

Can you clarify that?

If you disconnected the switch, cleared the code, ran it and there was no code, then reconnected it and the code returned, that points to the switch.

Chris

Can you clarify that?

If you disconnected the switch, cleared the code, ran it and there was no code, then reconnected it and the code returned, that points to the switch.

Chris

Sorry Chris I was a bit confusing there. I disconnected it, there was no change in note of the engine or running problems. Checked the code with it still disconnected and no code came up. Reconnected it ran the engine for a few minutes re-scanned and it came back. So I guess this means new switch time. Looks like it just screws in.

Yep, faulty switch seems likely.

The function of the switch is to tell the ECU to up the power a bit when you are actually turning the steering, so disconnecting it wouldn't affect idling until you turned the steering. It might then stall.

It would seem unlikely that it has anything to do with your erratic idle problem.

Chris