Bad idle and kangarooing under load
Posted: 22 Jun 2014, 12:25
Hello again,
I'm on the verge of giving up and taking my bus to a specialist, but before I do I thought I'd see if you guys have any advice for me. I've been reading so much on here / wiki / google I wonder if I'm overcomplicating my problem. I'm learning a lot as I go here, so maybe there's something I've missed or misunderstood! Sorry for the long read...
Background to problems: Engine - 2.1DJ. Throttle body has been out as idle control switch didn't work, gave it a real good clean and adjusted the switch etc.
New leads, cap, rotor arm and plugs have been fitted.
Missing the Idle Stabilisation unit (never came with it, but was running more or less ok before).
Timing adjusted to a paint mark on the pulley lining up with the engine running smoothest not sure if 5 or 7deg BTDC only have basic strobe.
"Mixture adjusted" by MOT tester to pass emissions.
So it seems there are two potentially unrelated issues I'm having right now. One is a terrible idle and poor starting. It takes about four attempts to start from cold before it'll run. When it does run it's constantly hunting for idle at around 400-500rpm. Any attempt to open the throttle at this point invariably results in the engine stalling - unless I open the throttle quickly and push past this flat spot. Now the bad idle seems likly to be down to a nonfunctioning idle control valve (no buzzing/virating), but I am unsure if it is the valve or the module that's not working. I've checked it as per Bently and when checking the plug with the engine running the multimeter reads about 0.4v. I'm doubtful this is what it should be reading. If I can resolve the next issue, I might see if anyone local to the Fleet/Guildford area will allow me to swap some parts around to identify the culprit.
Second (unrelated?) more problematic issue is the kangarooing under load. After the engine has warmed up I took it for a drive down the road and when accelerating the engine starts kangarooing which I believe is an indication of overfuelling? Could this be caused by an air leak in the throttle body? The lower bush is shot and I cleaned a LOT of dirt out of it, potentially allowing unmetered air in - I have tried spaying with easy-start to see if the engine speed changed but it was inconclusive. Would this cause the bad idle also? Should I be considering the mixture adjustment that the MOT tester made as causing issues?
If anyone has any help / advice / suggestions / support they can offer I'll be thankful!
Cheers
I'm on the verge of giving up and taking my bus to a specialist, but before I do I thought I'd see if you guys have any advice for me. I've been reading so much on here / wiki / google I wonder if I'm overcomplicating my problem. I'm learning a lot as I go here, so maybe there's something I've missed or misunderstood! Sorry for the long read...
Background to problems: Engine - 2.1DJ. Throttle body has been out as idle control switch didn't work, gave it a real good clean and adjusted the switch etc.
New leads, cap, rotor arm and plugs have been fitted.
Missing the Idle Stabilisation unit (never came with it, but was running more or less ok before).
Timing adjusted to a paint mark on the pulley lining up with the engine running smoothest not sure if 5 or 7deg BTDC only have basic strobe.
"Mixture adjusted" by MOT tester to pass emissions.
So it seems there are two potentially unrelated issues I'm having right now. One is a terrible idle and poor starting. It takes about four attempts to start from cold before it'll run. When it does run it's constantly hunting for idle at around 400-500rpm. Any attempt to open the throttle at this point invariably results in the engine stalling - unless I open the throttle quickly and push past this flat spot. Now the bad idle seems likly to be down to a nonfunctioning idle control valve (no buzzing/virating), but I am unsure if it is the valve or the module that's not working. I've checked it as per Bently and when checking the plug with the engine running the multimeter reads about 0.4v. I'm doubtful this is what it should be reading. If I can resolve the next issue, I might see if anyone local to the Fleet/Guildford area will allow me to swap some parts around to identify the culprit.
Second (unrelated?) more problematic issue is the kangarooing under load. After the engine has warmed up I took it for a drive down the road and when accelerating the engine starts kangarooing which I believe is an indication of overfuelling? Could this be caused by an air leak in the throttle body? The lower bush is shot and I cleaned a LOT of dirt out of it, potentially allowing unmetered air in - I have tried spaying with easy-start to see if the engine speed changed but it was inconclusive. Would this cause the bad idle also? Should I be considering the mixture adjustment that the MOT tester made as causing issues?
If anyone has any help / advice / suggestions / support they can offer I'll be thankful!
Cheers