.... and I have something interesting to report....
IT RUNS!!! 🙂
...finally! I'll fill you in on the finer points in a moment but first to answer some questions....
I havn't fitted the temp sender yet, the wiring fo rthe temp sender is just tied up in the loom so that it doesn't get caught in any moving parts - I will look at fitting the sender today although I won't necessarily be able to mount it where it will eventually reside in my 1835, but as long as it is connected....... and if the temp sensor made a difference or not.
My 1835 will have an Engle 110 in it, however the engine that is currently fitted (and running!) the EFI is only a standard 1600, so only a standard cam.Another question - does your 1835 have a hot cam in it or not ?
...Now on to the startup issues. You might remember before that I felt that I had a vacuum leak, so I checked the manifold for leaks and re-sealed them....well, when I tried to start it again after this had been done, I still had a problem with what sounded like a vac leak. Whilst fiddling with the fuel map in an effort fo get it to start I did get it to start and run for around 3-5 seconds. Whilst it was running I noticed that the engine had quite a loud knock (but as this was a pre-thrashed engine on loan from my brother and as with all his engines it had had a very hard life I wasn't too surprised), but the engine was still only running (or attempting to run) on two cylinders. Completely frustrated, I decided to begin testing the mechanical devices to ensure that I wasn't having tuning problems because something wasn't working so I borrowed a fuel pressure gauge from my brothers workshop to test the fuel pressure...
To my disgust I discovered that the so-called high pressure pump that I had been sold wouldn't even move the needle on the gauge, so I had no fuel pressure...I then tried a flow test to see if any fuel was comming out at all - there was but still no pressure - I think that I was sold a low pressure pump:bounce - on the positive side - it is really quiet when it is running, so I may replace my current noisy low press. pump with this one in the future...
I managed to find a Kombi EFI pump (in unknown condition) in amongst a pile of EFI stuff that my brother has collected so I fitted this in place of the other "high pressure" pump. By this stage my brother had finished work and had come over to see how things were going... he watched the pressure gauge whilst I opperated the ignition. It took a couple of goes to ge the pump to prime, however once it primed the pressure shot up (the needle was on its second pass around the gauge when I turned the ignition off!) Yikes!😠
We decided to make an attempt at starting the engine with this pump, even though my brother felt that it had almost twice the pressure that the manuals said that it should have (although they do give the figures at an idle so....)
when we turned the engine over it made an attempt to run but stalled, however, before I could make another attempt to start it, my brother asked it I could crank the engine without the ignition/fuel as he felt that the compression was not right. We removed the ignition and fuel pump fuses and cranked it over, when I looked at my brother he had a concerned look on his face and was shaking his head... apparently the last thing he had done to this engine before removing it from the last car it was fitted to, was a compression test and he reckoned that it had really even compression on all cylinders, which it obviously did not have now.
He knocked the tappet cover off the 1 and 2 side and turned the engine over by hand... the No 1 intake valve was stuck open! A couple of careful blows with a hammer failed to improve the situation, so we removed the manifold end casting for a better look down the intake port - the valve seat had fallen out! I am told (by my Brother) that he has never seen a valve seat come out of an intake valve in a 1600 (type IV's - happens all the time, but never a 1600). A couple of phone calls later and Tim (aka mud bashing) was on his way over with a spare twin port head that he had laying around.
In just on 2 hours (which included a stop for dinner!) we had another head on the engine, had checked the compression and were preparing for another attempt...
The first couple of attempts resulted in exactly the same result as before - a short burst then stall...
My brother wanted to know what would happen if I tried to start it on the Camira calibration, so I loaded the factory cal for the Camira and pushed the start button... it backfired through the intake - more fuel was the cry, so I increased the fuel flow on the lower end of the fuel map (or so I thought) - still the same result.
After a couple of attempts, it was discovered that if my brother 'choked' the air intake by placing his fingers over the top of it, the engine would run for longer - needed more fuel, partucularly at idle - I adjusted the deceleration enrichment (upwards quite dramatically - from 0.8% to 25%!) and this allowed the engine to come to a very rough by still running, idle🙂
Whilst holding the throttle slightly open, I made some changes to the fuel map to see what the end result was going to be - the engine was still backfiring, and by this stage we knew that it was running way too lean as the exhaust pipes were starting to glow! I continued to push the fuel values up toward the rich end of the scale (or so I thought at the time) but things were getting worse. Now completely confused I went back though the map and reduced all the figures dramatically - the effect was immediate! The engine began to rev more freely and the backfiring dissapeared, we just thought that we had things under control when the engine flaked out.
Turns out that (we think) that we had run out of fuel - the Kombi pump was quite noisy (like it had air in it) and after a couple of key turns it went quite (and you could hear air being pumped back into the main fuel tank).
As the engine was so hot (from running too lean) that we couldn't get anywhere near it so we took some time to reflect on what had just happened - this is when we worked out the the closer you get to 100% on the fuel map the less fuel you are using - its a volumetric efficiency map, the less fuel, the more efficient the engine is running, so I had been attempting to start and run it at almost full lean! No wonder it would backfire and carry-on when I tried to start it!
My plans for today include replacing an old piece of fuel hose (that had come from the Camira), that has begun to split from the extra fuel pressure that the Kombi pump supplies, to track down a fuel pump from a Camira or VL Commodore to replace the Kombi pump, then check the ignition timing, before doing another run with the computer set to self-tune. Hopefully, by this afternoon I will have the engine running smoothly and starting every time. I will also be fitting the engine temp sensor, as the ECU threw an error after the engine had been running for about 5 minuites, telling me that it couldn't find the temp sender.
So there it is - sorry about the length of this post, however after 9 months of planning it looks like it has finally paid off. I can't wait to see how well the auto-tune function works - Ill let you know later today.
C'ya,
R
:thumb
