splutter and jerking on low revs please help
 

hi there i have got a 97 2000 uk standerd it splutters and jerks when u drive it without bringin the turbo in but once u bring the turbo in it flys it runs perfect i have put a new set ov plugs in tryed another coil and aslo tryed a boost selanoid erm airflow senser ht leads but still doin the same has anyone got any idear wot it is cos its really doin my head in now it does it from cold and warm but it doenst stall and it ticks over nice it just does it when u set of at low revs in any gear???????? please help

any fault codes showing? when you connect the plugs in the drivers footwell?

same happened my old wrx turns out it was the dump valve making it run like s**t once you came on to boost it was fine

havent tryed the codes yet just waiting for my mate to come cos he said he knows how to do them and i have tryed 3 other dumpvalves and its still doin the same???

Myn did same and was coil. correct spark plugs and gap pfr6b? other wise would of said boost soenoid. oil in vac pipes? air leak? cam / crank sensor?

try putting standard recirc vailve on its obviously not coils or plugs if its clearing on boost coils and plugs usually fail once on full boost

do i need to check if any folt codes are showing cos the check engine light is not on? and tryed my mates coil and boost soenoid pal and it still did the same and just put some new planenam plugs in its really doin my head in now it makes me look a right nob driving now cos it just slutters light mad and jerks i have to just put my foot down straight away to cure it

i would say airleak after maf as well. I had a leak from my dump valve and it overfueled and run really bad.

just put my standerd dumpvalve on and still doin the same will check again for any leaks any were but really carnt find any tho

my window relay has got really hot and a few other relays have 2 under the drivers side would that be owt to do with my problem??

Could be wiring somewhere. Always good to check the codes as takes 30seconds, then can clear everything in memory. Try a battery hard reset to see if changes.

how do u do it that pal my mate was suppose to come and flash it last night but he didnt come some one said there is some plugs under the dash all i can see is a little black plug on a blue wire that is dangling? my ecu is 8s if that means anything

Reading codes:
Turn the ignition off
Find the diagnostic connectors. They are usually under the dash on the drivers side near the centre console. There should be a pair of black connectors (1), a pair of green (2)and a big yellow one (3 We don't need to worry about that!). You are looking for the black pair.
Connect the black connectors together.
Turn the ignition on but don't start it.
Check the engine management light comes on. If it doesn't some snake in the grass has disconnected it! This happens because people are scared of having to take the car to the dealer to have it fixed!
Count the number of flashes. Long flashes count for 10 and short ones are single units. So the code 38 would be 3 long flashes then 8 quick ones.
If it just flashes long flashes continually there are no codes stored.
Anyway, count the flashes and check against the list below.
Turn the ignition back off then disconnect the black connectors. If you mess things up just disconnect the black connectors and start again.

Fault codes:
1111 No codes stored
11 Crankshaft position sensor
12 Starter switch faulty
13 Camshaft position sensor
14 Injector no.1
15 Injector no.2
16 Injector no.3
17 Injector (You guessed it!) No.4
21 Engine temp sensor
22 Knock sensor
23 Mass air flow sensor
24 Idle air control sensor (usually accompanied by running too fast/slow)
31 Throttle position sensor
32 O2 sensor
33 Vehicle speed sensor
35 Emissions canister purge valve
38 Torque control signal (Automatics)
42 Closed throttle position
44 Turbo wastegate regulator malfunction
45 MAP sensor
49 CO adjustment resistor for older cars not fitted with cats
51 Neutral switch (Manual gearbox)

Clearing codes:
Make sure the engine is up to normal temperature (the cooling fans have just turned off)
Turn the ignition off
Connect the green connectors together

and connect the black ones together too
Switch the ignition on but don't start it.
Check the management light is on.
Drive the car for about a minute above 10mph
Stop and rev the car to at least 2000 revs for at least a minute
Check the light flashes 4 long flashes (Indicating fault code 1111)
Switch the ignition off and disconnect the green and black plugs

hiya scot right first ov all thanks for that pal big help right done it and its saying its the maf senser but i have tryed my mates on but saying that when we did it i didnt go for a drive init but i reved it and the splutter was there but like i said i should ov drove it now but he just gone to flanmingo land yesterday so might go try find one next week and also i reset the ecu and did wot u said but it still drove like a bag ov **** unless i put my foot down will my maf corse that to do that cos if i unplug it the car cuts out?

Need to be sure you didnt introduce the mafs fault into the ecu ie if had ignition on when unplugged it etc. Ermm some car runs and some dont, not too sure about that with scoobies when disconnect mafs when running. think you need to get your mates known good car, take one item at a time which could be the issue, clear codes, drive car and see how drives. Still thinking coil, exact same fault as myn light throttle faulted when boosted all clear. Has this fault just happen or since you did something to the car?

Another check, remove the pressure pipe from the tpiece from turbo to actuator which goes to solenoid valve (so just have a single pipe from turbo to actuator) and eliminate solenoid valve. This is a common fault in my experience and can give your symtoms.
Check the turbo actuator, you should be able to move the rod by hand with some effort but not too easy or vacumm gun if have one and check pressure when opens.

Where is your location?

Is it using lots of fuel?

Worth doing a compression test

Simon

Is it using lots of fuel?

Worth doing a compression test

Simon

someone said something about that valve in the pipe but then they said it would be over boosting or something but it boosts perfect i will try upload a vid ov whats it doin on youtube tomoz and let u see for your selfs and about the fuel its not really using loads but then again i havent really drove it for a long time as i have only just put the engine and loom in last week as i did a complete change to the car i.e engine,loom,paint job ect i bought the car with no engine so i won one on ebay smashed up but it was a p reg with the coil on top ov the engine so i had to do a complete loom change from front to back but it still did the splutter in that car i just thought it might ov been cos its been stood up 4 a while but i gave it a full service b 4 i put the engine in mine.its really head blagging cos i changed the coil and drove it with the other one on and still the same its as soon as i set of it does it but just as the turbo comes in its fine.will do a vid tomoz and let u all here for your self see wot u think then thanks again for all the help so far tho glad i signed up now :)

Usually gets oil in the valve causing fault. Timing correct? Take front covers off and make sure all pulleys line up correctly with timing marks. Will be interesting to see that vid!

i havent a clue about the timing ect ect will have to wait till my mate comes back of his holiday to check that lol and will have a look at that valve in the morning and also will def put the vid on tomoz to let u see and hear for your self mate.oh and i have taken the battery lead of now 2 and will try do that code think again tomoz in the morning just to see if it brings up the maf again? god knows i just want it working perfect now done a lot to this car now spent some man hours on it now i gave 300 quid for it with no engine and body was rottern so i striped it chopped out all the rot welded all new back in painted it that new audi white to witch the car was red before and put this engine and loom in got loads ov pics of before and after will upload them when i no how 2 bit ov a newbie to this at the mo :(

right had the battery of all night just put it back on now and its just flashing at me so take it it has reset it self? if so the splutter is there still arhhhh just waiting for my mate to get his arse out ov bed then will upload the vid.

scot your the man mate thought i would do everything again wot u said and well carnt beleve it i toke all the plugs out and one was only closed so opened the gap cleaned and hey presto it runs perfect now i never thought ov looking at the gaps when i put the plugs in i just toke them out the box and put them straight in how daft do i feel now will still put a vid on today tho ov my hard working project so again would like to thanks everyone who has given me some advise i hope i get to be a subaru machanic one day lol and do the same for u all big thanks again and scot i should ov listen to u be 4 and checked the gap give me a slap round the head if u ever see me pal haha

Not a problem, you will find this forum very helpful! Now you can enjoy your Impreza!