Engine running erratically
I have a 1999 Pajero iO 4G93 and have been having intermittent engine issues for over a year now. There appears to be no rhyme or reason to when the problem occurs; some days it’s fine, some days it’s not.
Basically the engine will suddenly lose power and feel and sound like it’s not firing on all four cylinders and the engine light comes on. If you pull over, shut it down and restart it’s generally fine and back to normal although it can take a couple of restarts to get there. It also suffers (again intermittently) from low idle and will sometimes shudder and stall immediately after starting or if stuck in traffic. It’s been through a few mechanics and over the last year the coil packs and ECU have been changed and the throttle body and MAF sensor cleaned – on more than one occasion. But still the problem persists.
This morning I put in a new fuel filter in and it started and drove like a dream for 30 minutes. No low idle and it felt a lot smoother. Problem solved or so I thought. Parked it up for an hour, drove it for five minutes and it went again – misfiring, engine light on etc, etc. Soooooo I am out of ideas really, has anyone suffered from the same thing and found a cure?
It's the MPI. No, I haven't
It's the MPI. No, I haven't had it checked but after yesterday's near miss with the fuel pump I have booked it in for a diagnostic this afternoon. Probaly should have done it some time ago but hey ho, better late than never. The trouble is that the various mechanics I've been to have all assured me that it was A, B or C and that they have changed/cleaned the offending part and it's all been fixed. We shall see....
If the CEL turns on...
Once the ECU turns on the check engine light, the first step should always be to read the codes - the engine controller is telling you that it's seeing something it should not be seeing. If you're not reading the codes yourself, make sure whoever does it gives you the actual numerical code, and not just the translation. different manufacturers use the codes differently, and the manuals will often list troubleshooting sequences based on the code.
At this point all we can do is guess at where the problem might lie, based on experience with a different vehicle, and based on your description of the symptoms - we don't even have the luxury of being able to see, hear or drive the vehicle and actually experience the problem.
One question, since you haven't mentioned it - when last were the plugs changed? Has anyone looked at the EGR system?
Is yours electrical related?
I’ve got the classic idle issue when in gear. Is stuck in traffic. Damn thing sounds likes it’s purring then does the “hiccup” and almost stalls. I cleaned the maf and it seemed to help the purring is not as aggressive but the hiccup still happens. I’ve noticed it’s worse in colder weather, and when I turn on lots of accessories (blower motor, signal light, radio, ect.) I’m leaning towards getting a higher amp rating alternator but haven’t made the purchase yet.
In a manner of speaking yes.
In a manner of speaking yes. One mechanic told me that he had come accross something similar and suggested I check the crank-shaft pully. He said that the keyway can become worn resulting in the pully moving independently of the crank-shaft and becoming misaligned with the crank-shaft sensor which in turm throws out the timing. That's why when you stop the engine and start it again it normally works fine as the pully then 're-aligns' Most people said that was a load of bollocks but when I took off the pully sure enough the keyway was worn. Really worn.
The other thing I found was that the welch plug in the front of the block was leaking slightly and water was dribbling down right onto the crank-shaft sensor. So I'm not realy sure which was the culprit, the pulley or the sensor but I changed both, replaced the plug and it has run just fine ever since. Prior to this in various attempts to fix the problem I've changed computers, fuel filter, coil-packs, plugs, cleaned the MAF and throttle body etc. etc. none of which worked. So if you can't figure out what's causing the problem it's probably worth checking the pully and the sensor.
My pajero is down at the
My pajero is down at the moment pretty big coolant leak at the rear of the block. I was sure it was the “T” at the heater core but It didn’t fix it. (Waiting on a different pressure tester that actually seals on the rad) I’ll definitely check the pulley when I’m working on that. Never would have thought of that. Thanks
Syndicate
GDI or MPI
Which of the 4G93 engines do you have? If the check engine light comes on, there's going to be a code set - have you had it/them read?