In my book the owner is a bit of a hero. He did not do the conversion but left it to someone with more experience and then drove the car here for mapping. Believe it or not he made the whole journey on two cylinders! He knew it wasn’t right but had no idea how to go about sorting it out.
I checked the software and found it was set wrong. Putting the configuration file right had it sounding much healthier – but now only on three cylinders. I went down the row of cylinders pulling one coil at a time until I found the one that was doing nothing. Normally a quicker way is to check the exhaust pipes and locate the cold one but on this installation it was easier to pull the coils.
As a quick check on wiring I swapped the dodgy number one coil with its neighbour and number two cylinder then stopped running while number one came to life. This eliminates the ECU, the wiring and the engine so a faulty coil was the obvious problem. Given the history of coil problems on this engine nobody was too surprised. A replacement coil solved the problem and the owner is going to get a spare ready for when the next one fails, as they will in due course.
I see a lot of cars here with spark problems, often with the spark breaking down under load. The first thing I do is check the coil on time setting in the software. 3ms is abut the norm but you can increase this on most engines to 4 ms under full throttle and at higher rpm to see if this has any effect. Next I run a temporary feed direct to the coil from the battery. This eliminates the low tension side of the wiring. Quite often you get 12 volts at the coil but the current flow isn’t up to the coil demands under high load conditions. A direct feed wire eliminates that one.
On turbo cars you can often find the plug gaps are better closed up a little. Modern engines running weak mixtures often have gaps of 60 thou (1.5mm) and these can be closed down to 25 thou (0.6mm) to see if that helps eliminate the problem.
If none of that helps then I find my slave coil and lead set and wire that to the car direct to the battery and direct to the ECU. This eliminates the coil, the HT leads and the wiring loom all in one hit. I use a Ford coil and some very long aftermarket leads that can be temporarily lashed to most engines. Unless your weak spark turns out to be valve bounce that will definitely sort it!
This little Mallock with the mid-mounted K Series engine kept misfiring and breaking down at the track. It was all a bit last minute with an event coming up that weekend so I agreed to work late one evening and try to sort it out.
On the rollers the car misfired straight away and I opted for a change of rotor arm. The early K had a dizzy with a single coil and the rotor arm is a known weak point. Straight away it pulled clean to 8000rpm, big smiles all round and an early evening finish was on the cards. But it wasn’t to be. When I tried to do a bit of mapping the misfire returned but more like a dead cut and re-set than a misfire.
Quite often you have two or more problems giving similar faults and it can be confusing when trying to track it down. With time being of the essence I ran a live direct to the ECU from the battery and the earth from the ECU direct to the battery negative. I wanted to eliminate any obvious interference in the loom straight away. But it made no difference and a look at the running log showed up a missing speed signal from the crank sensor. We made up a new crank sensor wire (using shielded wire) and that solved the problem.
I believe we had a break in the loom which lost contact at certain engine vibrations so the speed signal came and went at a certain engine speed. Another hour after that had the map licked into some sort of shape and we finished about 9 pm. Not as bad as I had been expecting and no noise complaints from the neighbours - which is what keeps us from working the hours that we used to.
You might recall that young Jono here has a Fiesta which was making 88 bhp in stock form and we fitted a Piper manifold with sports cat and gained ten bhp straight off. The plan was always to fit Jenvey direct to head bodies but like all our best laid plans for engine development, things got out of hand. BPJ were going to do a head for us with a pair of their Piper cams but the 1400cc bottom end was a bit tired and Paul at BPJ had a new 1600 Puma bottom end we could use so before we knew it we were building a complete 1600cc engine for Jono’s Fiesta.
There was a lot of discussion about the stock 1600cc bottom end and Paul advised us to stick with the Ford set up. Apparently you can get up-rated bolts but the rods need to be tapped out to take them and those are the ones that Paul had seen let go. My mate runs his Puma with a stock bottom end to 8000rpm all the time so we ended up leaving well alone.
So the new spec was 1600cc bottom end, BPJ ported head and cams, Piper exhaust manifold and Jenvey direct to head bodies. Jono did his own mapping and admits to being very nervous about it. He has been here three years now and normally he is pretty quick at mapping but on his own engine it all seemed different – which I can relate to having mapped the old shed engine recently.
The end result was 172 bhp at 7000rpm and 134 ft lbs of torque at 6350rpm. When I say end result I really mean the result at the moment. The power was still going up but with Jono’s head full or worry about engine rpm he didn’t take it past 7000rpm. He is going to put a 1000miles or so on the engine and then I am going to give it death on the rollers…are you reading this John?
It gets a bit boring banging on about internet muppets but this one needs to be scotched before it gets out of hand. Someone was trying to start a war between another mapping man and myself. I have known Steve Greenald for something like 15 years and we get on okay. I always recommend him for mapping if it’s a DTA system (although he does all of them) and he is the only person I have ever loaned my rolling road to.
So when an internet Muppet tried to start a war between us we got together and scotched it straight away. I even let Steve in the building wearing his DTA shirt and offered to buy him a meal at our local restaurant: that’s the sort of bloke I am, money no object.