Spluttering

[DEREKCO]

Once again help is needed car started fine this morning then after about 1 minute the engine starts spluttering revs drop to about 200 rpm ,apply throttle nothing ,then revs build up quickly ,take foot off throttle ,back to spluttering also smell of excess fuel ,switch off , start engine again fires on 5 cylinders then back to spluttering, ran a San using vagcom only code is 00513 which I know comes up when the engine not running ,only other code that came up was 00537 and 00525 both linked to lambda probe then they disappeared HELP any ideas. Car is a 93 ABY S2 Coupe

[newsh]

Spluttering

Maybe lambda has died
Unplug lambda see if it changes. It's the single connector, the 2 pin one is the heater.
If that doesn't work try cleaning MAF connector or unplugging MAF

[DEREKCO]

Spluttering

Unplugged lambda no change ,will clean MAF in the morning dark and cold outside

[S2TORNADO]

Clean and dry the spark plugs.

[DEREKCO]

Spluttering

I cleaned and dried spark plugs still the same starts fine on 5 cylinders ticks over sweet for about 1 minute then drops to spluttering

[DEREKCO]

Spluttering

Ok disconnected lambda completely no change , cleaned MAF sensor no change ,as before cat starts first click , then lumpy tickover till it stops ,ran a scan 00513 code then 00537 O2 control ,then 00525 then 02 voltage low G39 erased codes now nothing I cannot replicate the codes ,car still erratic tickover very difficult to rev when it does it awful smell of unburnt fuel ,its overfuelling so am going to change 02 sensor

[newsh]

Possible broken fuel pressure reg

[DEREKCO]

Spluttering

Ok further update , took off isv tested with 12 V works fine , checked all vac hoses , nothing ,car starts fine ,idles fine then after about 1 minute it starts to go on lumpy tickover ,I have checked plugs ,coil packs everything is ok , gotta be that lambda probe ,unless anyone else can think of I have missed some , ps I tested all the fuses everything is ok

[DEREKCO]

Spluttering

I also tried taking the car for a drive to warm engine up nightmare , car behind me thought I was a learner driver ,(kangaroo driving)

[Mikes2]

lambda probe doesn't do anything on a cold engine - it's bypassed / ignored

[John.]

Possible broken fuel pressure reg

I was thinking fuel pressure too, but would the FPR fail in such a way? ....to cause high pressure/over fuelling?

How old is the fuel filter?

[newsh]

I was thinking fuel pressure too, but would the FPR fail in such a way? ....to cause high pressure/over fuelling?



How old is the fuel filter?

If the diaphragm in the FPR ruptures, fuel flows straight through the vac tube into the inlet manifold

[LHD_Kid]

Really sounds like lambda... this does nothing for the first minute until its warmed up.

Have you tried the new one yet?

[DEREKCO]

Spluttering

OEM lambda delivered tomorrow as I have previously stated the car starts and runs perfect for about 1 to 2 minutes then the erratic lumpy tickover starts when this happens I have tried to throttle through it all I get is popping and no throttle engine eventually stalls , am convinced it's the lambda probe but will stand corrected if not ,only reason I am stating this is that many years ago I had a 2.0 ltd h reg coupe which had a near identical fault ,I found out it was the lambda probe ,this fault is near the same , on Thursday night when I started the car to come home from work it started acting up ( symptoms described previously) I ran a scan and came up with 00513 speed sensor you get this when engine is stationary other codes were 00537 02 sensor control & 00525 02 sensor voltage low .I unplugged the connectors ran a test then reconnected them I cleared the codes , later on I tried taking the car out and the above issues started ,I now cannot get the car to reach operating temp to do another scan and lambda test ,Am I missing doing something ,as I say it starts perfect but resorts to lumpy uneven tickover ,,SORRY IF THIS IS LONG WINDED

[LHD_Kid]

Pop the new sensor in when it arrives and update us all with how beautiful it runs...

Makes sense its the lambda. If it starts fine and only has issues after a minute or 2....

Good luck !