1998 TVR Chimaera 4.0 - Turbocharged.

Yea, I'm warming to injectors given the current ignition system is barely a year old.

If you have a link to bench testing them on Youtube it would be handy!

I'll test them to verify fault, but I can see me beefing up all 8.

I cannot find the exact link I used, but this ghetto setup gives you the basics.



I used a spare fuel pump to give me decent fuel pressure and a 12v battery to power it and the injector.

I did four tests..

1) Simple 'does it flow any fuel' to check for blocked injector.
2) Leak under pressure ?
3) Thirty cycles, measure how much fuel
4) Spray pattern, I used dark card to spray fuel onto to check it.

My car had 4 injectors
- Two flowed pretty much the same and had nice spray patterns
- One leaked fuel all the time and had a spray pattern that was a drizzle. In the test it put out a lot of excess fuel.
- One worked intermittently and also had a horrible drizzle pattern.

I bought a pack of four as it was cheaper that way, when I tested the new ones, they were very well matched so I installed them and called it a day.

That would explain a lower than expected result - would have expected to see closer to 150 psi

A fully open throttle for the test (and all the plugs removed) gives the best results in terms of determining differences between cyl's

Everyday is a schoolday - I intend to only stop learning when I die

My water leak turned out to be the radiator, or at least the "primary" leak was. I've replaced almost all of the non engine coolant system, so I may need to suck it and see for a while to establish if I am still losing water...

God, 6 months of thread neglect. Poor show.

I won't go into the long winded cause of that, but to summarise ... The Chim is now out of the Skunkworks because, well, there is no more Skunkworks. At least, not in the current location.

I'm moving back to my homeland of Glasgow, so all projects and whatnot are scattered in various places in various states of completion.

The Chim I've decided to update simply because it was the only one that drove into its trailer for the move. Yup, winter hibernation over, and I actually got it running again



What's been done? Well as you can just about see, a new alloy rad is in there, which took some fiddling as its considerably thicker. I've silicone upgraded the last of the coolant lines so it's all as new again. I've started upgrading the intake but only sourced an elbow so far.

Less audible is the addition of a Walbro 240lph external pump. It's running healthy but I will address the suspect relay soon too, as soon as I work out which one it is. I've obviously sorted the leaking headers too. Got some fresh oil still to grow in her, along with a new sump gasket.

This month it will go for an MOT and see what's what. Hopefully not much else will be needed and I can use it for another summer of fun. Could use a fun toy right about now after 6 months of spannering!

Lack of old job mostly. My previous location is having a bit of a rennaisance at the moment, from thriving oil rich to not so much. I'm originally from.here anyway so duked out while the going was still good.

6 months since an update.... shameful.

So whats been happening? Well, after fitting the new master cylinder and enjoying a month of happy brakes, the misfire issue reared its ugly head again.. properly.

So far i had swapped out fuel pump, relays and fuel line (not related but the lines were a bit ropey looking). I had scant issues after that, so in my usual fashion, I dug no further and left it. Big mistake.

Cue a full TVR weekend, we all head out on convoy up north, and pop. Sizzle, smoke, and dead car. I wouldn't have been as miffed about this if I hadn't been in the middle of the Clackmannanshire bridge at the time.



A few of the TVR boys doubled back and pushed us off the bridge, where she was once again loaded onto the back of a flatbed for a shame trip home.

And there she sat. I;m ashamed to say, sat for several months too whilst I licked my wounds about finally killing it. Then, in the midst of winter, I got the coveralls on and got into it.

After some digging it became clear on what had failed. The ECU. I pulled the cover off and found a ruddy big hole in the middle of the board, right in the middle of the fuel circuit that controls the injectors. This was starting to make sense... my clean exhaust bore on one injectors side, the constant barely-perceptible missing on load, the occasional drops in power.... the ECU was cooked, and had been frying for quite some time.

OK, this would be easy then? Swap in another ECU and away we go? Well sadly not. My fear was that the ECU had been cooked by something else. Did i have a live short that had thrown a significant amount of amps up the ECU's farter and blown it? To throw another in and have it fail would be an expensive mistake. It was time to get deep. I started to remove the full loom in preparation to fault find the wiring.

I needn't have bothered. Unsheathing the loom at the exit of the ECU end, I found many black earth wires that had melted, indicating a large umber of things. Mainly that the loom had seen too much heat, not enough earthing to the chassis, and given the hardening on many parts of the engine end, was unfit for use.

OK, now chalk up a new loom to the bill. By now, said bill was becoming counter productive. I'm not one for simply replacing, and it would be hundreds for a new ECU and loom for it to have the same inherent issues.


Time for aftermarket engine management.


The bullet was bitten. In the end, after some research, I settled on Megasquirt. A lot of TVR circles look down on it, but after speaking to Phil at ExtraEFI I knew I had no doubts. The beauty here is the boys there do Rover V8's for breakfast, including the TVR, and as such a specific loom could be knocked up. I wont lie, it came in at the same price as a set of used Lucas components. No brainer.

So... in my ethos of never replace: upgrade, I have come up gold again. Last night I started to get the parts on that had been steadily arriving. As the original lump uses very little in the way of technology to run its EFI (distrubuter and coil for ignition, 2 bank injection with MAF for fuel) there is considerable improvements to be made. First off, the new ECU will need a method of calculating engine position, so a crank trigger is needed:



Enter the 36-1 specific trigger wheel for the serpentine RV8. Fitting was a scoosh, pull the old pulley off, remove dust cap and align up the teeth to the original timing mark, then bosh it back in..



...pardon my dickbeaters blocking the view. Once on, the magnetic pick up was next. Again, Phils kit was childs play to work with, and the pick up was on in minutes, and adjusted to gap with ease.



Stay tuned for more progress soon.

Good to see some updates on this Overdrive!