37 replies to this topic

[dennisb]

Like it says above, when I start the car in the morning (from cold) it runs over normally and fires quite quickly, but after ignition it shudders and splutters for a few seconds, then evens out to an almost normal idle - although it is a bit lumpy and rough. Also, when it starts, I get a quick blast of whitish smoke out the back. It doesn't last that long, not even a second, but enough for me to smell burning oil (because it's in the garage).

I can't see any or smell any when it's warm sitting still idling and I'm at the pipe. When on the move and up to temperature there is no sign of smoke, that I can see anyway. The car is generally running badly though when on the move - hesitant at various revs, there's a definite misfire, usually around 2000 and 3000 it's worse, but it's noticeable everywhere.

I thought all of this was maybe due to the fan coming on all the time, and maybe causing a mixture problem, but I have since changed the harness to the temperature sensor - but no change to the strange running. I has new plugs and new leads and a clean air filter.

I have only very basic skills with the car/engine, so go easy on me please! I have a few pals with more skills who could help me once I'm told what to look for. I'm hoping a trip across the country to someone with a code reader will help me, but thought maybe going on the symptoms there could be some things I could check myself before going on a tour.

I hope someone can help me, or offer some advice on things I can check...

Thanks in advance.

Dennis

[mykweb]

what year and is this and MPi or SPi ???

also what engine mods you have or is it standard?

Mike

[dennisb]

SORRY - crucial omissions !!!

It's a 2000 MPi
MED St 3 head
MED 1.5 Rockers
52mm Throttle body
K+N filter in Rover airbox
Fuel pressure regulator
W+P Stage one exhaust system

I had problems a year or so ago with rough running, but that was different to this, and traced back to a bad lambda, which was changed there and then and cured it. The garage who fitted my LCB and exhaust damaged the original sensor. Since the lambda swap the car has been running well - until now.

[mykweb]

I would say the trip to see the code read would be a good idea.

I had a similer issues after refitting my engine, the car would run super lumpy and would need a good press on the GO pedal to get it even started. I stripped the Idle Control Valve down, and replaced nearly every fecking sensor under the bonet with no result. I fincally got someone with a code reader to help me out. The issue pointed to the map sensor. located on the right hand side of the Inlet manifold.

I am not saying this is your issue, but I was getting very hesistent acceleration. I would floor it and there would be a 2-3 second lag before the car would kick into going. Was a real pain when pulling out from round abouts. Also when I floored it I would hear a pop coming from the Inlet manifold. .

even when sat still on teh drive the car would vary in revs, almost self reving, and it would backfire throu the inlet manifold, and then ammept to stall, then at the last minute revive its self.

After replacing the map sensor it did help, but will had issues, I ended up swapping the engine wiring harnes and all issues went.

I would get some electrcical contact cleaner and clean the plugs on the Map, Inlet temp sensor, ICV, Coil Pack plug, crank and cam sensor (located at the back of the engine) also the two multiplugs on teh ECU.

Remember and allow it to dry before connecting abck up and firing up.

If you are using teh code reader get someone who knows how to use it. It can lead you down a path of buying parts you don't need if you read it wrong.

Mike

[dennisb]

Thanks very much for your detailed reply Mike !!!

I'll do what you say about the cleaning of the sensors, it certainly can't do any harm, yet it might also be the cure.

You reminded me about backfiring. I don't know if it's an actual backfire (i thought they let out a loud bang) but it makes a lot of popping noises when letting off the throttle and slowing down, not at other times. Don't know if this is a factor?...

You say electrical contact cleaner... is this a specific thing or would wd40 do the same job? Like I said, i'm not up on engine capers!

Cheers,

Dennis

[mykweb]

wd40 leaves behind a film residue

you can actually buy electrical contact cleaner from your local motot factors or halfrods.

You might just find that the slight popping when letting off the throttle is unburnt fuel being burnt off on the manifold on the way down the zaust. My car does this only for the first 10-15 mins when its slightly cold. Once the engine is up to temp it goes away.

One way to check to see if its popping throu the Inlet manifold is to take the air filter off the car, and start the car, then go around and stand over the engine and listen to the inlet manifold, Not to close mind LOL. but at the same time rev it a little buy moving the throttle cable on the side of the throttle body. Rev it and let it go. Do this a few times to see if it pops or splutters from the inlet.

The other way to check for a missfire is to by HT lead spark LED's . They fit inline to the spark plugs. And flash when they are fired. REMEMBER DON'T TOUCH THE HT LEADS WHEN THE CAR IS RUNNING, MODERN HT LEADS CAN GIVE OFF A LETHAL SHOCK.

Infact I have just thought of another Thing. You say you have repalced the HT leads, Di you make the school boy error in taking them all off and then putting on the new set. If so you might not have the Leads in the correct sequence. This causing the car to misfire.

There are two ways for the plugs to go in the MPi depending upon the VIN number of your car. There were 2 different types of Coil Packs fitted to the MPi.

Here is the first way

Looking at the coil pack from the front (thermostat end) of the engine. Cylinder 1 is nearest the water pump, cylinder 4 is at the flywheel end. The engine firing order is 1-3-4-2.

* Bottom left on the coil pack goes to plug 1
* Bottom right on the coil pack goes to plug 2
* Top right on the coil pack goes to plug 3
* Top left on the coil pack goes goes to plug 4

Or the other way that mine is set up is

* Bottom left on the coil pack goes to plug 4
* Bottom right on the coil pack goes to plug 1
* Top right on the coil pack goes to plug 2
* Top left on the coil pack goes goes to plug 3

I just remembered when I was putting my engine back together I had real problems trying to get the engine to fire. I nearly bought a new coil pack at £150

Mike

[dennisb]

Thanks again Mike!

I'll get to halfrauds over the weekend then and get some cleaner.

Tonight, I'll check for sparks and also check that the leads are connected properly. When I swapped the leads last time, I did it one node at a time to make sure it was exactly as was. That's not to say though that I got the car the wrong way! No harm in checking anyway, if I funk it up I can put it back the way it is now.

I'll reply back with my findings!

Cheers man!

[mykweb]

Just be careful if testing the HT spark leads the old fashion way by slowly pulling them off when the car is running.

The spark hurts. I still get a tingle in my arm, months after doing it

MIke

[dennisb]

I've got some long armed insulted grips and some big-ass rubber gloves - should be ok.

If not I won't reply, because it'll probably affect my dodgy ticker in a negative way!

[cbyrne]

iv had same brob but no smoke a had flames instead that killed my maniflow system... check the vac lines from the bac of the inlet manifold the 2 off the rubber ends cracked on mine im guessing from the heat off lcb. hope this helps as i no how pi**ed off it makes you!!

[dennisb]

iv had same brob but no smoke a had flames instead that killed my maniflow system... check the vac lines from the bac of the inlet manifold the 2 off the rubber ends cracked on mine im guessing from the heat off lcb. hope this helps as i no how pi**ed off it makes you!!

Another top tip - thanks man - Ill check it out as soon as I'm allowed back in the garage (angry wife!)

[mykweb]

tell the wife that your baby (the car) is ill and needs looked after.

Could be the reason I am single lol.

Mike

[dennisb]

I'll bet you're happier though

[mykweb]

maybe.

I have just read where you are from. Paisley, Not to far from me. I am in livingston

Mike

[cbyrne]

ha iv a girlfriend the exact same neva lets me work on my mini!! the way i checked mine was to pull the black pipe from the ecu and stick it to your cheek to see if there is suction