FUEL SWIRLPOT to suit 240 Volvo - by Anthony Hyde 1/2003

FUEL SWIRLPOT - The Volvo 240 fuel tank has a good design to keep fuel pooled around the internal fuel pump, fine for nearly all uses. However, around a racetrack typically on a very hard left hand corner combined with a low fuel level, the 'In-Tank pump' can momentarily pickup air, and the air feeds into the main pump and an instant pressure loss occurs at the injectors, followed by fuel leanout and engine hesitation - not good !


This small swirlpot capacity is approximately 0.8 litre or 0.2 US gal.

ACTION - an external fuel swirl pot will solve this problem - an extra reservoir of fuel that sits between the pre pump and main pump. Using the 740 in-tank pump detailed below, the pot should keep itself well primed, hence no real need to have the return injector rail line feed into the pot as well, just leave it alone to return normally back to the fuel tank.
Without a swirlpot, the only way to avoid a potential drop in fuel pressure on hard left hand corners is to have the tank well-over 1/3 full.

Advice - In-Tank pump (or Pre-Pump): I advise all 240T owners to upgrade to the 740 Turbo (B230FT) higher tech Delco in-tank pump #VO-3517845 (plus you need the new bracket #VO-1312390). Pre-Pump filter is #VO-1274818. This pump flows more and at a higher pressure (4.4 psi @ 5.5 amps) vs (old 2 psi @ approx 2 amps).
As the 740 pump is about 1" 25 mm longer in length, you need to trim (hacksaw) about 25 mm off the long steel feed tube before fitting the joiner hose. Basically you make the new pump sit at the same bottom length as the original. You will need to affix a longer earth wire as well. 2x Nuts for 740 pump wires are an odd 3.5 mm. (old 240 pumps are 6/32", 4mm)

Advice - Main pump: #VO-9142045 740T (B23FT,B230FT) to 960 models.
If upgrading a 240 pump with K-Jet you will need to obtain & fit some adaptors to connect to the K-Jet fuel accumulator.

MOUNTING - The swirlpot can be mounted high in the free space situated between the front left corner of the rounded fuel tank and the panhard bar mounting bracket. The left side main chassis rail protects it from the side. The unit lines up with existing fuel lines that route through the panhard bar mounting bracket, so no issues there.

Interestingly, a leanout wasn't evident with the former K-Jet mechanical injection (after fitting Haltech EFI, I did remove the K-Jet fuel accumulator that holds extra fuel volume). Probable though that fuel demand has increased with big EFI injectors, as lap times improved. I only confirmed the leanout during a track test day when I had time to observe my air / fuel ratio LED's. When mentioning this observed problem to a 242GT driver with a similar aftermarket EFI set-up, he too noticed the same lean-out issue with his vehicle at the same point on the circuit.

* DISCLAIMER *
PLEASE NOTE any information offered on this web page is free and without guarantee. Should you choose to perform any of the procedures listed on this page, you will be doing so of your own free will, and I will not be held responsible or liable for any damages that might occur from using information obtained here. The information stated here, is to the best of my knowledge, accurate. However, in order to safeguard myself legally, I make no claims that it is in fact accurate in every, or any detail.
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