Injection Engine starting Problem

[centro]

Hi

I have a T25 with 2.1 in injection engine. This morning it started first time but I had to apply the throttle to keep the engine going as it sounded if it was going to cut out. When I took my foot off the throttle the engine stopped. I then could not get it started. The only way to start it was to lightly pump the throttle when turning the ignition on ( I should not need to do this with an injection engine). Any ideas what could have caused this to happen?

Cheers.

[RichardF]

For a start, check:

1) small green wire on coil upper terminal, and yellow connector in same wire, check both are tight and connecting well. May be hidden away under the relay box.

2) connections on water temp sensor, on LH front of engine

If no luck, check all connections to and from ECU. Diagrams are in Haynes Manual.

[TimC]

Similar situation, but not exactly the same: 2.1 SS (LLE). When cold, the engine behaves normally. When almost warm (eg if left for 10 minutes after driving), the engine will start ok but won't pull. In neutral, I can hold the revs at, say, 2500 for 10 seconds, then on its own it will reduce to a rough idle, with plenty of misfires, for 20 - 30 seconds before dying. If I restart immediately, it will respond more or less normally for 10 seconds, then repeat the dying swan act. This goes on until it gets to roughly normal operating temperature, then it's OK. Any extended idling will bring the symptoms back - very embarrassing in traffic!

I've checked the Wiki (printed it out, even!), and searched the site for info. I've replaced the plugs, distributor cap, rotor, and HT leads with no change. I found the lamda sensor connection rusted beyond conductivity, but replacing that made no difference. I saw your reference to the temperature sensor - and reference to the T2 sensor in the Wiki - and disconnected it to see what the effect was. It responds a bit sluggishly, and idles at 1800 rpm, but is more or less controllable. Reconnecting the sensor restores the problem. So - a new sensor ordered from JK. Is this diagnosis logical and likely to lead to a cure, or have I led myself up the garden path?

Cheers

[TimC]

Yep, garden path it was. New T2 sensor, no change. All connections checked, but no faults found and no change. In the process I decided to fit a new JK engine lid seal (which is solid not hollow), which overstressed one of the lid catches which then snapped. Not a good day. Anyone any helpful thoughts - about the running problems, not the engine lid catch!

[TimC]

Bump - I'm running out of ideas, and would be very grateful for any clues! It's a 2.1 SS engine with Digifant injection/ignition system.

[RichardF]

Sorry to mention the temp sensor again, but I found the plug for mine faulty.

There was a very slight corrosion on one contact and the little blades inside were spread apart so they didn't always connect well.

[Aidan]

is the idle switch on the throttle body doing it's thing ?
are there any air leaks after the afm ?
are there any air leaks on the exhaust ?

[TimC]

is the idle switch on the throttle body doing it's thing ?

To tell you the truth, I've no idea! How do I tell?

are there any air leaks after the afm ?
are there any air leaks on the exhaust ?

Not as far as I can tell, but it's difficult to be certain. There's no blowing from any part of the exhaust system, and the general condition of all the induction and other gubbins around the engine is very good.
It's beginning to sound like this may be a garage job, but if there's anything I can do to reduce the amount of time they could waste searching for the problem, that would help.

RichardF The plug and contacts for the T2 sensor are in excellent condition, and I can't see anything to be concerned about there. The difference in behaviour between connected and disconnected suggests that it's working to some degree.

The clue, it seems to me, is in the fact that it only happens after extended idling or a after period switched off when fully warmed up. Also, the fact that even then it responds normally for a few seconds (20-30) after being restarted is significant - but I'm damned if I can get further than that!

Thanks for the help so far, chaps.

[famous phil]

Hi , trying to find Some of these problems may be difficult to explain ,,, Aiden points out air leaks , these may be hard to detect especially if your looking for blowing ,, its suction that you'll be looking for and sometimes it may only be found by checking one area at a time with the engine ticking over ( if still able to do this ) you can use a non silicon spray like WD40 , if you spray near each injector to see if the seals there are ok , then around pipe fittings , if there's a leak you may see the fluid drawn in or more so the engine tune will change ,,,

Regards Phil

[big red bus]

You did change the right coolant sensor? not the gauage sensor but the coolant temp sensor for the injection system. Symptons sound very similar to coolant temp sensor fault to me. What colour was the sensor you changed. Black or blue.?

[TimC]

It was at the blue plug, underneath the thermostat housing pointing to the LHS of the vehicle. Shown as No 1 on the diagram 10.1 on page 4B.6 of the Haynes manual. The replacement sensor has a black plastic plug part, but is otherwise identical to the blue-bodied part removed. It's Just Kampers part no. J13717, VW/Topran part no. 251 919 501D.

I agree, everything I read suggests this is the culprit. But I can't find anything wrong!

[ermie571]

try a replacement replacement....from someone other than Just Kampers? Does Brickwerks do one?
Or is there someone near you with a known good one you can test in yours?

Em
x

[big red bus]

Blue plug and black sensor? blue plug should go to blue sensor and black plug to black sensor. Think that is what is it designed for. MAy be wrong because its been a while but thinks thats how it works. So you need a blue sensor.

[TimC]

I'll ask Brickwerks and see what they say. GoWesty might have some info too. Bullibarn isn't too far away from me - I'll ask them too.

[R0B]

the one you want...
http://www.brickwerks.co.uk/index.php?p ... t&Itemid=6" onclick="window.open(this.href);return false;