Hi guys,
Having a mid-life crisis and bought myself the car that 20 year old me wanted. Zero mechanical experience, hadn't even changed a tyre when I bought my 1990 JX Sierra. No concept of what I was getting myself into - car drove fine, thought I'd just be on the hook for some cleaning and tidying - in actual fact I'd bought myself a tired little Swift GTI (I think MK2) wrapped up in my SJ70, which after a month of driving decided to idle at 3k rpm. I took it to a local mechanic, who said the cold start valve was faulty and he blocked it off, said just to give it 10mins to warm up then all should be fine but then it started bogging down whenever I'd apply throttle, and in the end got so bad it would just stall whenever I'd try to take off. After much fussing about reading the million and one posts about high/low/erratic idling, then testing and cleaning all the things, she now idles at an excruciatingly low 100-300rpm (even with the air bleed screw almost all the way in) and stalls at the smallest hint of throttle...
I understand this is an air/fuel mixture issue but I can't seem to work out what exactly is going on. I can see it's common practice to delete the cold start valve so I'm wondering what has gone horribly wrong here for me.
Things I have done so far:
- checked for vacuum leaks (none)
- cleaned the throttle body
- cleaned the MAF sensor (did not touch the delicate wire)
- cleaned the iacv
- tested the TPS sensor (within spec - "kind of", when I do the adjustment procedure I can't seem to get it to sit at OL)
- tried to get the error codes off the ecu but the previous owner butchered the loom so can't find the monitor coupler and even with the diagnostic ports bridged at the ecu, the CEL does not come on - I don't believe the CEL has been integrated with the swift wiring properly.
- checked the spark plugs (fine)
- changed two fuel filters and one fuel pump (have a pull, push setup with a small surge pot). I changed the pump at the tank, because I thought it sounded like it was labouring, but the new one makes the same sound so it was a bad guess - fuel delivery doesn't *seem* to be the issue, although I haven't done a fuel pressure test.
Before I rage quit and pull the entire thing out to start from scratch (ie. get it reconditioned + new loom) - does anybody have any suggestions on what I should try next? I'm reluctant to go buying a bunch of new parts without knowing for sure that is the issue/s (learnt that lesson from the fuel pump exercise).
TIA
