7 replies to this topic

[jwb_moto]

I have a 98 Paul Smith MPI which has covered approx 54k, it has recently had a service (oil, filters, plugs, leads) and is bog standard apart from a green filters element and a maniflow cat back exhaust. The coolant and oil both look normal

Whilst my girlfriend was driving it today at approx 40-50mph at about 2500-3000rpm ish and the revs sundenly dropped to zero for a few seconds and then back upto normal again, it did this intermittantly all the way home (about 10miles)

I have been out and started it and its still doing the same, ive held the revs steady and 1k,1.5k,2k,2.5k,3k etc to see if the problem occurs at a particular rev band but its seems to be doing it all the way through the rev range.

what could the causes of this be? am i on the right track by thinking lamba sensor or MAF sensor could be dodgy?

Any help gratefully appreciated.

[remzors]

I had a similar problem to you where the engine would misfire and splutter. I took it to the garage they said there was no visible problems and so i had it serviced and it still spluttered. So i bought a new fuel pump as i thought that might be the problem and hey presto its been fine since then although for one day it went back to old ways and started spluttering again but then the next day and for the last few weeks its been fine.

However, other people on this site have also had a similar problem with spluttering and they have tried many things to fix it and most end up getting a power boot valve for the fuel pressure. I have just got one myself actually but i havent fitted it yet as for the last few weeks my car has been fine.

Not a clue if this may be related but my mini mpi also has a maniflow exhaust and yesterday two of the brackets snapped off. All fixed now but maybe check your brackets as maybe that could be a reason but i doubt it.

[mykweb]

not sure if the PBV will solve this.

Have you had the car checked on the Diagnostics to see if any of the sensors are showing issues or faults. Its really the only way to tell.

If its cutting out its sounds like an ignition issue. Possibily HT leads. if they are old they can become worn, and when you serviced the car this could have cause a hairline crack. Before you go shelling out £80 for a PBV that you proberly don't need I would try the HT leads, or cheeper sill a set of HT lead testers.

Mike

[R1minimagic]

You can get an OBD2 diagnostic tool for about £80 which should tell you if a sensor is out, and probably dead easy to sell on afterwards if you want some money back.

http://www.talktomyc...aders/mj007.htm

[Blatherskite]

Whilst it was spluttering, did you notice whether the exhust was blowing lots of dark grey smoke? Had a similar problem, and it turned out that the coolant temp sensor connection was loose at the sensor. Pushed it back firmly on, and no problems like that afterwards. Worth a check, anyway.

[jwb_moto]

cheers for the replies people. I replaced the HT leads about 500miles so hopefully it shouldnt be them.

I didnt notice any dark smoke but there was a little bit of moisture which i thought a little unusual as it had been driven about an hour before and it has been a nice day here. plus a fuel smell as if it was running a bit rich

Ill check the coolant connections in the morning

[tmsmini]

Was the fuel filter changed as well as the oil filter?

Terry

[jwb_moto]

no it wasnt, theres plenty of fuel as it running rich tho