850 97 Losing power

Solutech · Post by **Solutech** » 15 Oct 2009, 05:13

Hey guys long time no post but my 850's sick . A few days back it started to jump and buck like crazy losing power and stalling at low revs or idle . Seemed to be the same as when the sparks needed changing so I changed the sparks . Old ones were black and sooty . No change so I disconnected the MAF . Idle improved as did power . I removed the MAF and gave it a good blow out and it seemed better well for about 1/2 a mile then it was bucking like a bronco again .

I bit the bullet and bought a new MAF . The car now idles at 900rpm but the power is still lumpy as hell . If I mash the gas it kicks and misses and the revs hover about 2500 . Adding a little gas at a time it will go to redline . Im now totally lost as to the cause and need some ideas .

Its drivable with MAF disconnected but it drinks juice like crazy and power sometimes just isnt there . Far from ideal lol.

Thanks fellas .

FCPEURO · Post by **FCPEURO** » 15 Oct 2009, 07:20

I know you just did the plugs, but when was the last time you did everything else like the air and fuel filters, plug wires, etc..? Sounds like a clogged up fuel filter to me.

Solutech · Post by **Solutech** » 15 Oct 2009, 07:31

When plugs were replaced about 12 months back I replaced the rotor arm,cap and leads . All are still in good condition . The fuel filter I havent done so it may be worth replacing . The air filter again is in good shape .

FCPEURO · Post by **FCPEURO** » 15 Oct 2009, 07:32

Solutech wrote:When plugs were replaced about 12 months back I replaced the rotor arm,cap and leads . All are still in good condition . The fuel filter I havent done so it may be worth replacing . The air filter again is in good shape .

Ok, in that case, change out the fuel filter and report back.

Solutech · Post by **Solutech** » 15 Oct 2009, 08:07

Surely if the filter was clogged then disconnecting the maf wouldnt improve it . Car revs much better without the maf . But after a quick check the filter looks to be quite old . Note on UK models the filters on the drivers side

thought I was going barmy for a while looking on passenger side .

Post by **misha** » 15 Oct 2009, 16:50

Did you replaced it with oem Bosch one?Because if not,this is something you could expect.
Is check engine light on?

Solutech · Post by **Solutech** » 15 Oct 2009, 17:36

The CEL is on as I disconnected the MAF . Its been lit for 12 months since I last disconnected the MAF trying to diagnose a similar problem . I havent had the codes cleared as it requires a reader I dont have and none of the local greasemonkeys has a reader that will link up to it .

The MAF I removed was a Bosch . The replacement is a generic unbranded OEM .

Solutech · Post by **Solutech** » 16 Oct 2009, 05:19

I changed the fuel and air filter earlier . No change . Idles lovely but wont rev correctly on full gas it gets to 2500-2800rpm and bounces back n forth. Smooth revving with a little more pedal at a time and it revs all the way up to redline . Again disconnect the MAF and it wont idle but revs up fine . Im running out of ideas now other than putting a rag in the tank and lighting it .

dbo550 · Post by **dbo550** » 16 Oct 2009, 05:44

I would double check all of the vacuum and intercooler hoses for cracks and make sure they are all hooked up. And look at the plugs again $10 is about as cheap of an insurance policy to be had. Most larger auto parts chain stores will check and clear your codes for free.

Solutech · Post by **Solutech** » 16 Oct 2009, 05:50

The plugs are brand new . And I live in the uk . The garages near to me have code scanners but so far none have managed to read off the codes .

All hoses are connected theres nothing leaking I'm stumped .