12 replies to this topic

[Brooni1]

Hi there can anyone help me I have a 1995 1300spi I've just rebuilt the gearbox after 2nd gear problems, the trouble is no thAt I have the engine back in and running it seems to be running rich when it warms up a bit? I thought it would be the coolant sensor so changed that but there's was nothing wrong wth the old one as I've tested it hot and cold. So now I'm scratching my head the new spark plugs are sooty black as if the chokes been running on, it ticks over fine when stone cold as soon as it warms up its lumpy and the idle goes down then eventually cuts out !! Please someone help

[David128]

Hi  first thing to check. Air leaks at manifold .then idle air control valve.

[spiguy]

Does sound like the car is staying on cold running settings even when warm. Although you have checked the sensor out of the car, what does the temp gauge read when the engine is warm?

 

Alternatively it could be an issue with the vacuum line to the ECU. Check that the pipes are fitted correctly, not split or pushed on too far either. Should be a small one from the inlet manifold to the fuel trap (black plastic box clipped in near the air filter box) then a long one running from that down to the ECU.

 

I have had this on an SPi when coolant wasn't flowing in the inlet manifold, but that was noticeable by the fact that the gauge read cold even once warmed up.

[FlyingScot]

Hi  first thing to check. Air leaks at manifold .then idle air control valve.

No inlet air control valve on SPi...

FS

[FlyingScot]

As per spiguy, but on pipes and fuel trap, bin them and replace with a new set.

These are service items and they fail due to the heat and wear and tear, most haven't been replaced regularly.

This is the commonest issue on SPis so eliminating that possibility is a good start.

FS

[Brooni1]

I'm planning on putting the manifold back on tomorrow with the new sensor in it ! Vacuum pipes seem ok blew threw them and the was no obstruction! Do you think if the engine main earth was very slack that would make this happen ?just noticed I hadn't tightened it up there

[FlyingScot]

Mate don't go there... rely on blowing through, visual inspecting etc, just bin them and start again.
Have a look on here; there are lots of threads where when questioned members stated they were fine and then later found issues....
Unless you do, you could be chasing your tail....just saying....

FS

Edited by FlyingScot, 30 October 2015 - 07:13 PM.
Poor language

[David128]

Agreed. 1 porous or split pipe nightmare

[Brooni1]

Is the vacuuming pipe not just for advancing timing though?

[gazza82]

But if it leaks it also leans off the fuel mixture ..

Edited by gazza82, 30 October 2015 - 11:42 PM.

[spiguy]

Is the vacuuming pipe not just for advancing timing though?

 

not on the injection cars, no. The vacuum line to the ECU tells the ECU what the engine load is by way of providing engine vacuum to a sensor (MAP - manifold absolute pressure) in the ECU body. Fuelling requirement is directly proportional to engine load and so it is probably the single most important measurement used in the ECU's control. when they leak, the ECU thinks there is less vacuum and so more load, and ends up vastly overfuelling.

[Brooni1]

I see :) makes sense now! Do you ever get problems with the map sensor in the Ecu then ?

[FlyingScot]

Rare to get sensor problems with the MAP (it's soldered on the MEMS ECU circuit board) but make sure you replace the fuel trap to stop liquid reaching it.

Most injection problems are due to lack of servicing and of course typical mini wiring problems (corroded connections and poor earths)

FS