21 replies to this topic

[ICAM]

Car starts from cold every time, no problem, runs at elevated revs (function of ECU acting like a choke I guess?) for about 5 mins and as soon as it is warm, revs drop back and engine ticks over no problem. On driving away (i.e. engine under load) and engine still only "warmish" it runs without missing a beat but as soon as it has run for about 15-20 minutes (up to operating temperature?) the hesitation starts. While progressively pressing the throttle their is a hesitation to pick up which does not clear until I press pedal to the floor! Hesitation and Splutter is evident also when trying to "feather" the throttle, i.e. when motorway/dual carriageway driving.

Electric fan is cutting in and out at what seems to be the right time, it certainly takes 1 good 15 minutes or so before cutting in when stood ticking over.

Also, (see previous posts) there was a full diagnostic checkover with several parts changed only 900 miles ago.

Not sure what more I can say?

Engine is coming out soon for gearboe it and everything x rebuild at which time it will get a thorough clean and checkover.

I have expirience that a few months back. It took me about three weeks to solve it. Finally I found that my rubber vacum joint for MAP cracked. Replaced it and everything fine. But mine is SPI, not sure wheather same or not with yours.
Hope this will help..

[BoyracerAU]

ICAM, I'm just wondering - is this joint outside or inside the ECU itself?

I'm asking because I know there's another black rubber tube inside the ECU that goes from the port at the bottom of the ECU housing up to the MAP sensor, so perhaps it was this one.

[elvisthepizzaman]

boyracerau, MPIs have their map sensor mounted directly on the intake manifold. only spi cars have tubes running to the ecu.

[ICAM]

boyracerau, MPIs have their map sensor mounted directly on the intake manifold. only spi cars have tubes running to the ecu.

Oh I see. It totally different from my SPI. If that the case, so you should try and clead it using compress air. If cannot means that you need to change it.

Boyracer,
There is a few rubber joint that you need to check for SPI. Black hose connect to MAP sensor at the ECU (outside the ECU, see attachment), Red hose(From manifold to ?) yellow hose( From Manifold to air box flap). Very easy to check, try and bend it. If it no crack and the joint is not torn then it should be ok. Otherwise replace it. For my cased last time the joint crack and making my car stall whenever engine at working temp. When cold engine is normal. I just simply replaced all of it with normal automotive vacum hose and use tie rap to secure it.

Attached Files

•  Rubber_joint_hose.JPG   164.29K   37 downloads

[BoyracerAU]

Sorry to hijack a thread. It's definitely not my intention! But I must say the symptoms sound very familiar.

ICAM, all my vacuum lines and elbows are fine. I've taken them all off and blown compressed air through them. I've even held my thumb over one end whilst blowing air in from the other and they're all leak free. They're all on nice and tight, so whatever's causing it doesn't appear to be vacuum related.

[BoyracerAU]

Elvis - sounds like MPI's are a better set up if things aren't all bunched together. I hate buying a whole whaddayacallit just because the little doodad is stuffed.

[craig 1010cc]

unless the crank or cam sensors are broken by some physical force they generally last a long time. however, they are magnetic, so a large collection of metal bits on the end can affect the pulses.

I had to change the crank sensor on my 98 cooper Si the other month as it's loom had broken down between it and the connector but that caused a terminal misfire (but a slight break in the wire/insulation would get worse as it got hotter?)