12 replies to this topic

[pete l]

Hi all. My mpi rebuild is causing me problems. I've changed almost every sensor on the engine. It now starts and runs but it is very rich, so much so that it stinks like and old car with the choke out. Its lumpy and bogs down.
Any ideas ?
Thanks.

Pete.

[FlyingScot]

Is this part of the same problem you already had and posted on....?

FS

[pete l]

No not really. Before it wouldn't start etc. It turned out to be the MAP sensor. I got a new one and it fired up straight away. A few weeks ago, when I got the new MAP, I had it ticking over in the garage and it seemed fine. Got the engine up to operating temperature etc, had the fan kick in. But I didn't drive it.
Today it went for its first run and its running rich and lumpy.

[ukcooper]

inlet manifold gasket is leaking I'm guessing , fit a new one and make sure it sparkling clean when fitting the new one could be wrong usually I am.........

or with mine I bought a special components lcb and fitted the lambda censor at the y peace

[pete l]

This is the thing, it is new, as are all the sensors

[ukcooper]

might be new but was it clean any crap old gasket will create a tiny hole that will cause a air leak ... had it before , dose not matter if its new if its fitted wrong ..especially gaskets

[pete l]

It was a special MPI manifold gasket. 

 

How can a tiny hole create overfueling ?

[ukcooper]

cause to much air getting in and the ecru compensates by putting to much fuel in making it run rich , same with any car might still have a special MPI manifold gasket was it clean. Oh and your censors beaning new dose not mean there working I had faulty ones in the past and if your sure and checked there all working and fitted correctly, must be the wiring loom or to big a back box mine hated that ..had to move the lambda censor to the y peace..

[pete l]

I'll check it out.

 

Another thing, my MAP sensor was dead so I got another one from mini spares. Thing is my original one was MHK100490, the new one is MHK100600. Anyone know what the difference is between them ? I ask because I was told that the MAP reading should be around 100kpa with the engine off. I'm getting 74kpa with this new sensor.

 

I don't know what any of that means though

 

Pete.

[pete l]

No one know anything aboout MAP sensors ?

[Sprocket]

if they are the same scaling, and im led to believe those are, they should read around 100kpa at sea level with the engine off.

[Sprocket]

The wiring and connections are at least 18 years old, so not uncommon for there to be issues there.

[pete l]

I've already checked the wiring and tested the continuity back to the ecu plug and all is OK.
My diagnostic reader is showing 74 kpa. I'm not at sea level, probably about 40 meters up.