399

Hi, just when you think your getting on top of a few jobs on the car 1999turbo.


Starts up great and as it warms up starts sounding lumpy, if you hold the revs at 1500/2000 you can hear it mising slightly.

On driving when i accelerate it hesitates and misfires upto 3000rpm/boost but no poping from the back. Then it pulls well upto 5000rpm but still down on power a little i think but then it gives one big misfire/hesitation at 5000rpm.....then pulls again ok ish.

Theres no CEL light on!

Jobs recently done.....

spark plugs/leads.....air/fuel/filters.....knocksensor......new/rad......cambelt/pullys....

It would be great if anybody has got any idea or could set me off in the right direction.

thanks martin

Themexican

iTrader: (5)

it could be your MAF sensor, i had similar problems to what you have described.

i went about changing plugs, leads, filters etc etc, and it ended up being the MAF.

You could always take it out and clean it too see if it rectifies the problem, until you can get another. The other thing that will tell you if it is the MAF, unplug it while the car is on. If its working properly it should cut the car out and if it stays on its normally the sign its knackered.

Hope this helps

Themexican

iTrader: (5)

Oh yeah dont boost until you have solved this problem otherwise u run the risk of a big bang and a bigger bill.

BLU

iTrader: (27)

Check all the leads are connected to the coil and plugs properly.

Then check the belt hasn't been put on a tooth out.
(these are all free so do them first)

Then if all ok and still no change you need to see if its thrown any codes up by connecting the two wires under the dash, this will tell you if theres a sensor fault. (I know you said theres been no cel, chances are if its an electrical problem it'll have flashed up briefly just as you weren't looking!!)

399

Thanks for your replys.

I did the cambelt my self and checked and rechecked, it also fired up first time and it was fine for agood while after that so im pretty sure that should be ok.....he says!

Although the top right hand side (looking from the front of the car) cam pully did slip over cam as i was lining the marks up turning it clockwise! but it was fine after.

I,ll try and read the codes but not done that before! also i,ll unplug the maf and see what happeneds.

martin

399

up date.... I've unplug the battery for an hour to rest the ecu and it ran fine, alot smoother. Then after about 15/20 went back to mising.

I then unplug the maf and she cut out

BLU

iTrader: (27)

Which points out theres probably a sensor issue.

Have you done a code check yet?

399

Any more ideas on this one lads im a
bit stuck. I will try and read the codes today.

BLU

iTrader: (27)

Impossible to diagnose until you have any codes......

399

Hi, No codes what so ever came up today. I might receck the cambelt.

alcazar

iTrader: (2)

The above, plus borrow a known working MAF.

You ARE using the correct notch on the crankshaft pulley?

399

Yes im sure i have, i looked into it months before i change it, i've just tried to get a photo up of the cambelt fited but no luck. I might buy maf and try it but i didn't want to go down that route! it might be the coil !

I'll take the spark plugs out and regap them to 0.65 and see what colour they are i might of done some damage when the pully sliped over

BlueBridge Subaru

iTrader: (1)

It sounds like maf , they might as well be a service item on a 99 impreza ..

alcazar

iTrader: (2)

You haven't said what mods the car has, if any?

399

None its just a standard RB5 with 98000 on the clock.

winston69

iTrader: (30)

ANy developments?

399

Hi, Well i did a compression test today and they all came in at 152psi with warm engine and open throttle!

Is that abit high??

The spark plugs are abit white? so its running lean....... I replaced the spark plugs and gapped to 0.75mm from 1.00mm

It don't seem to pull like it did before i've just done the plugs and its still lumpy.

I've also change the maf....

not sure what to do now??

alcazar

iTrader: (2)

I'd have it over to Carnetix at Melton Mowbray.

399

Well had it tested today and what do you all make of this lot......?

No codes shown....

Emissions @ idle

c/o 0.0%

h/c 07

co2 12.8

o2 0.5

Mix lean

m.a.s voltage idle 1.28 (0.8-1.2)

coil output on 1&4 low

cam sensor res 2.4k

cam sensor trace faulty

How can all that lot happen over night?????

And where do i start to fix it

399

Hi, can anybody work that lot out.

I,ve got cam sensor on its way.

where can i get a cheap coil from?

What will sort the running lean problem out?

Any help would be great on this.....


He also says the lamber sensor is switching in and out but very slow????

He didn't tell me alot more info more time cost more money!!!