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Putting 1988 Lotus Esprit Turbo back together


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1988 lotus esprit. Brand new engine rebuild by Arnie Johnson in Atlanta 2 years ago. Tried to fire it back then and it wouldn't so I covered it and started on it again this month.  Will fire and idle for a few seconds with starter spray in plenum (only have tried a few times, as the spray will damage the fins on turbo if repeatedly used), but not getting gas, even though fuel pumps energize with key on and system pressurizes when trying to start. Ive checked current to very thing. Ive checked inertia switch, all relays, fuse and vacuum hoses. Only one that shows no current with key off or in on position is the Bosch fuel distributor. Maybe has current in starting mode? I'm going to test the cold start injector to see if it is squirting.  any thoughts?

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I have not worked on the bosch in a a long time, dont the fuel distributors have a propensity to gum up when they sit?  Do you have the book on how those systems work?  I want to say the the wire leads to a heater for cold weather warm up?  And wont influence your start issue - I could be wrong.

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Arnie Johnson has an impeccable reputation so no worries in regard to his work. Are you familiar with the American community over at https://groups.io/g/TurboEsprit ? There has been much informed discussion on the Bosch EFI system there.


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Could be things outside the engine...


Tried using fresh fuel? Crimp/block the fuel hose to the pump, and use a hose in a gas can with fresh fuel.

During this exercise, look for debris coming from the gas tanks. Hopefully the fuel was FULL during storage, otherwise might be rusty flakes blocking flow. (Tho', not likely to totally prevent fueling)


You not only need fuel PRESSURE, you need fuel VOLUME. Procedures for checking are in the Service Notes.

Your roll-over valve might be to blame.. The ROV is located in the RH sail panel. I removed mine and cleaned it, but for troubleshooting purposes you could more easily disconnect the hoses to it over the RH gas tank, and flush it with intake/carb cleaner.

You can diagnose a Cold Start Injector by temporarily plugging the tan connector for the WUR to the CSI.

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Atwell Haines

'88 Esprit

Succasunna, NJ USA

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  • 4 weeks later...

You said the fuel system pressurizes with key on... The fuel pumps are wired to only energize at crank and run. They are triggered by the RPM relay with a negative signal being sent to the pumps - Look for ground and 12v from battery and 12v from ignition here.

Do you know what your primary pressure and system pressure readings are?  The injectors should open at around 45psi (just over 3bar). You should have primary pressure around 6.5 bar and control pressure around 2.5 bar (should be lower at higher altitude).

Looking at the crank circuit, both the cold start injector and thermal time switch are only energized at crank. make sure the white / yellow wires coming from each are attached to the starter such that they only energized at crank.  Finally, make sure your Aux Air is fully open when engine is cold. With the cold start injector operating properly, the engine needs the additional air from Aux air valve.  

Another obvious check is the timing... this will bite you every time.

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