Fuelling

Along with the brakes, fuelling is an issue for my Tamora.

Like the brakes not being right, there is no good reason for this…

As a note, the car always runs on Shell V-Power. Occasionally it has to put up with a tank of BP Ultimate. All fuel information is online here.

I first thought something was a bit off with the engine in Feb 2012 when doing hard accelerations up to ~ 100mph at Millbrook. The 3rd gear pull was accompanied by what I called a fairly quiet (over the noisy car) ‘crackling’ noise from the exhaust manifold area. I don’t get this on the road so much since I don’t typically load the engine as hard.

In November 2012 the car went to TVR Power for a few dyno runs. See write-up (and video) here, and a picture of the results with air-fuel ratios here.

The AFR sat at ~ 14 through the run, which is a little on the lean side. Jason checked the map, and the fuelling was as it should be for full throttle runs.

There was some subsequent discussion with Jason, reported here.

August 2013 was a full 12k service at TVR Power (here), which included injector removal and cleaning.

Flow rates below:

Cylinder number, Flow rate before, Flow rate after

C1     74     75

C2     74     74

C3     73     74

C4     75     74

C5     72     75

C6     75     75

Notes were:

Before – Injector flow fairly consistent but poor to fair spray patterns across all injectors. Resistances all at upper limit, ave = 14.1 Ohms.

After – Little improvement on static flow rates, but slight drop in resistance.This will give a faster opening and closing rate resulting in slightly more opening time. Excellent spray patterns.

Everything was checked, what could possibly go wrong at Millbrook in October 2013. Plenty as it turned out, see here.

After the high-speed driving (few mins at up to 130 mph) I was left with a car that was running badly, a lot of heat from the exhaust manifold, and knocking under low-rev load.

It was recovered to TVR Power, and the issue was a fouled plug on cylinder 6 – details here.

That fixed, it was driving ok.

Nothing more was done until the August 2014 service at TVR Power.

It was found that one of the cats was partially melted (see pics here). However, this was the cat for cylinder 1-3, not the cat for cylinder 4-6 where I had the plug problem.

TVR Power can’t see why it isn’t working, and the proposed route is larger injectors (Red Rose) and a custom re-map which takes a full day. This is quite a lot of money, and I wouldn’t see any of it back if I ever went for a 4.3 or similar (unlike my uprated starter motor).

I am keen to find out if there is anything else that can be done. The engine runs well, does not use oil or water, so why can’t it run properly under load?

Answers on a post card.