Put this through the NCT (MOT) a few weeks ago, passed with flying colours - somewhat surprisingly - not sure why it was such a surprise given the amount of work done, but it been a while since it was done, and something trivial always crops up. Have been using it daily since, which is a pretty good way to discover all the other jobs it needs done. It actually drives very well (again - not sure why that's such a surprise) but did need some issues resolved. The main one of those was some horrendous idling - way too high, with the car shaking, poor starting, and kangarooing at light throttle (which I'm pretty certain is a clogged up TPS) .
Starting point was the ICV - cleaned it up, seemed like the internals were moving freely - and refitted. Absolutely no improvement. Decided to tick off the quick jobs - so swapped out the blue temperature sensor next. Anyway - started the car up and the revs were sitting bang on where they should be at roughly 700rpm. Idle was still very rough though.
Decided to swap out the plugs, ignition cable, rotor cap etc at this stage. The plugs were definitely past their best - or connected to a boat anchor at some stage.
Again, no real improvement, and with no ide of the history I decided to buy new injectors. Its turns out that brand new injectors from Bosch are now more or less the same price as having the old ones refurbished here - so put in an order for a set. In the meantime it was bugging me that the ICV might not be right. The Bosch original ones aren't available anywhere at the moment, and paying BMW €700 for one isn't a runner. So a spurious German one was bought from eBay which was fitted yesterday, and, the idle seemed more or less perfect ,with a tiny hint of a misfire at idle, so I'm still happy enough to be replacing the injectors.
Also went ahead with a new chip - sourced on here. Someone at the post office decided to stand on it though, so when I opened the package I was greeted with this -
Luckily I'm pretty gifted with a pair of tweezers, so I was actually able to straighten out all the pins and get it seated correctly in the ECU. I haven't spotted any significant difference as yet - but it gets good feedback, and it was cheap - so we'll see how it goes.
Otherwise it was being kept clean, most of the time.
The issues with the idle quickly returned after fitting the new ICV unfortunately, which I suppose shouldn't be totally unexpected as it wouldn't be at fault for the kangarooing which I was experiencing. It basically left the throttle position sensor, injectors and AFM as the potential issues.
The engine on this car has a different TPS to normal since it was originally in a switchable auto car - and it made it a pain to source. New ones were around €370 - whereas a standard TPS is around €150. My nightly scouring of eBay resulted in me finding a brand new Bosch one in Germany for €70 - so snapped it up as quickly as possible.
With the injectors and TPS being replaced, it was an opportune moment to do the rocker cover again. Had it powder coated originally, but the finish was beginning to bubble slightly and there was some oil weeping around the edges. Picked up a spare one and did a VHT special -
I used this a few times in the past and struggled to get a decent finish but realised the key is to load up paint like theres no tomorrow. This photo shows the drying process quite well (I applied heat!)
A sensible decision was also made to hand the car over to Xworks (him of the E30 rebuild thread on here) to fit up the bits and resolve the idling issue - Brian knows E30's inside out and is well able to diagnose issues which are beyond my ability. It was pretty good timing - the day before I was due to drop it over the idle got significantly worse, and ended up cutting out once or twice.
Anyway, firstly - and embarrassingly - I'd left a cap on one of the plugs. Wasn't specifically causing my idling issues, but probably wouldn't have helped either.
Before replacing it, Brian tested the TPS - it was failing every 10/15 times - so definitely needed to be fixed -
New injectors went in next - they look different to the originals, but are the correct spec and work fine with the M20 engine.
Two vacuum leaks were also found under the throttle body, which were fixed up. I can't imagine I'd ever have found them. A quick tidy up of the throttle body was done as well -
The car is idling perfectly now - Brian is doing a few more small jobs, but should have it back by the weekend - just need to find a space for it now that I've bought a new daily!
