Author Topic: Engine fires but wont stay running (Read 5327 times)

Lefty9000 · « **on:** December 12, 2023, 03:59:39 AM »

Hi all,

I'm new to this forum, and somewhat new to Honda cars. but certainly not new to working on all types of cars.

I have a problem that's somewhat out of left field, so to speak.

I have a Jazz Mk2 built 11/08 with a 1.3 iVtech petrol engine. BUT

my situation is the engine is no longer in a car, but set up to run a backup generator. I did the removal and setup of the engine, and pulled the entire front wiring harness out to use to set up the engine with the original ECU, ignition switch, gauges etc. I am also using the original petrol tank, radiator, exhaust. including both O2 sensors.
After setting all this up and trying an initial start up I cant get the thing to run. I bled the fuel as best I could and am sure its getting fuel but it refuses to start.
of course it is showing a bunch of warning lights in the dash, like ABS, airbags, steering, as these are no longer present, but I tested the car before pulling the engine out without these and it ran with no issues.
The one light I'm seeing that might be an issue is a blue temperature gauge symbol on the left of the dash.
Could the problem I have be related to the engine immobiliser? I've experienced similar symptoms with other types of cars if the key is not found. I do have the original key, and key pickup loop etc.
Although its not impossible some part of the wiring is not complete I'm fairly confident it's all ok.
Any suggestions on what I should look for would be appreciated

Cheers, Angus

GBH · « **Reply #1 on:** December 12, 2023, 08:00:17 AM »

Sorry I can't give a specific answer but if you could clarify the problem someone more familiar with Hondas may be able to suggest something.

Does the engine start?

If it starts, when does it stop running? Immediately or when you release the key from the start position?

richardfrost · « **Reply #2 on:** December 12, 2023, 08:47:14 AM »

Is it something to do with the stop/start system? Does this car even have that?

Lord Voltermore · « **Reply #3 on:** December 12, 2023, 09:11:07 AM »

My suggestion is the blue temperature warning may mean the ECU is receiving a misleading sensor reading (or lack of reading) and setting a very rich fuel to air ratio as if it were starting in very cold weather. Like being flooded by using too much choke.

madasafish · « **Reply #4 on:** December 12, 2023, 10:46:53 AM »

Blue temperature = cold To be expected when engine is cold. ,Not the issue.

Possibly you have damaged a key wire: crank/camshaft sensors? But if so, you would expect a warning light on dash. Did you remove the OBD socket? Or could you reattach it and read any error codes?

Failing that: remove a spark plug and test it sparks when the engine turns. You will need to earth one end of the plug to the engine. If you have a spark, then not immobiliser.

If you have a spark do you have fuel? Remove one injector, crank engine and see if you get a jet of petrol - care etc.

If you have both spark and petrol, then the cause is not immobiliser but possibly MAF sensor?Damaged?

One thing at a time: check ignition first.

Lord Voltermore · « **Reply #5 on:** December 12, 2023, 11:18:33 AM »

I accept a blue light is normal on a cold start. But I thought the ECU measures the actual temperature, both engine and ambient air temperature.

The OP is in Australia. The fuel/air ratio for a 'cold' start in an Australian Summer is probably not the same as whats required for a Nordic winter. It might run perfectly if its in Norway. But its just one possibility to consider.

Lefty9000 · « **Reply #6 on:** December 12, 2023, 10:00:37 PM »

Thanks, everyone for the replies, and sorry for the delay in responding ( I'll blame the time dif )

the engine starts and runs, but only for a second or two then dies as though the ignition is turned off again. Even with throttle input. because it fires up I had presumed it must have spark.
As far as I can tell the MAF sensor and wiring are good, and so is the key sensor wiring.
I did leave the OBDII socket intact, so I will try a scan when I get organised with a scanner.
The one thing I didn't think to keep is the ambient temperature sensor, so the blue temp light makes sense, and if the ECU thinks it is very cold it could screw up the air-fuel mix. can anyone tell me where this temperature sensor is located on the car? I don't remember if I saw it or not.