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1987 turbo HCI engine won't rev above 3000 rpm


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Hi,

I just received a 1987 turbo HCI I bought in the USA (I live in Paris - France);

I replaced the battery and this car that had not ran for 6 months started at the first turn of key with a very regular idle.

I decided to take a short drive around the block and found that everything works fine but the engine won't rev above 3000 rpm.

The only way to go faster is to get to an upper gear.

Stepping on the accelerator does nothing.

As soon as the car revs up to 3000 rpm it stops the car stops accelerating and I actually have to release my foot on the pedal to get it going again.

Any ideas ?

Nanardos

Sorry for the mistake at the end of the text:

Please read " the car stops accelerating and I actually have to release my foot on the pedal to get it going again".

Nanardos

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Few things it could be, but generally they relate to two lines of thought, spark or fuel. It is worth checking the air filter as well, I'll ignore the turbo being broken for the moment.

Spark, could be ignition advance etc isn't working correctly due to rusted parts/ ceased parts.

Fuel, (carb) could be blocked jet, (inj) could be low fuel pressure, both could simply be blocked fuel filter/ stale petrol.

Has it been serviced to any extent since it was in regular use?

If not, just check over things like contact breakers, dissy cap, plugs, fuel filter, air filter.

My TE (GM injection system) had a similar issue, that was generally down to the air filter being so clogged it was restricting the air supply.

The reason I ignore the turbo is, if it was OK before it was laid up, and you've not mentioned "I can't hear the turbo spinning up", chances are it's OK.

Andy

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Ok, thanks,

Sorry to ask a silly question, but I have parked the car and I don't have the time to go back and check now (neither do I have the worshop manual with me now):

Is there one or two fuel pumps on my car ?

( I did hear the sound of one only)

Nanardos

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Ok, thanks,

Sorry to ask a silly question, but I have parked the car and I don't have the time to go back and check now (neither do I have the worshop manual with me now):

Is there one or two fuel pumps on my car ?

( I did hear the sound of one only)

Nanardos

Hi Nanardos,

had a quick look in the hci fuel system infos, there is a primary and a secondary fuel pump.

Congrats to your new toy. Please attach picture!

As a long term member of Turboespritmailgroup (mainly used from the US) I remember a similar question like yours. May be needful to join there for you, as the hci is not very much around here in Europe, means not so quick specific help as typically in here. You are the unlucky person who has to read all this pages in the Service Notes describing fuel system and engine managment for the hci.

As Turbo boost builds up at 3000 rpm, it could be a disconnected vacuum/boost hose to the intake plenum, if you have a fuel pressure regulation valve with such a connector, not sure for the hci.

There are two other hci in Paris (one red, one black), check therefore Club Lotus France.

Good luck,

Rolf

Website with information and pictures PBB St Tropez convertible Esprit:

http://www.lotusespritconvertible.de/

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OK, Thanks,

I'll have a closer look at the connections, etc, tomorrow.

I don't seem to have heard the turbo so far.

On the contrary, I find the fuel pump pretty noisy.

I also have an oil leak somewhere at the turbo intake.

I'll try to attach a picture soon.

Nanardos

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SLIGHT IMPROVEMENT

Hi,

Things have improved a little this morning.

By looking into the "coil box" that is located in the trunk I

discovered that one of the two little 15a fuses was blown.

(the righthandside one)

I replaced it and the engine then reved well above 3000 rpm while the

car was parked.

Once on the road the fuse blew again.

I replaced it with a 20a and things improved again although the car

still "jumps" and the turbo does not engage at all.

Do you know what the fuse I replaced protects ?

Nanardos

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Hi,

I just read in the owners manual (page 21) that:

" an engine protection device is fitted which operates , in the event

of one of the two fuel pumps failing, to limit the engine speed to

maximum of 2500 rpm"

That explains at least part of the problem !

I guess I just have to find which pump is failing and replace it ...

And also find why the turbo isn't working

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It could be that you simply can't get the engine to run fast enough to get the turbo spinning. If you pull off the pipe to the compressor inlet, can you spin the turbo wheel by hand? It should turn easily. If not you probably have a problem with the bearing or damaged wheels.

I think I would get the engine running properly before worrying too much about the turbo. Sorry I can't help on the fuse question. All too new for me to have had experience with.

S4 Elan, Elan +2S, Federal-spec, World Championship Edition S2 Esprit #42, S1 Elise, Excel SE

 

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Haven't worked a Lotus "K Jetronic" but for other cars there is a feed and pressure pump. The pressure pump should be external and easy to check. Before replacing I would remove and clean it to see if there some type of foregn matter in there. Those pumps are genearlly very robust. About the only thing that stops them is junk or water. Given by what you have desribed I would guess it is the pressure pump you are having problems with.

Good luck,

Jeff

www.espritturbo.com

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Both fuel pumps are external and under the fuel tank on the passengers side of the car (assuming left hand drive)

The fuse you're blowing sounds like one of the fuel pumps... should be a pink wire coming from it?

As for why the fuel pump is blowing the fuse.... could be the pump itself.... or... you should check the fuel supply line from the tank... they have a habbit of crimping off and cutting fuel flow to the suction pump which will make the pressure pump have problems (cavitation which could over-heat the pump and cause it to blow the fuse)

Modifying esprit's.. now that's fun..

PS... I AM NOT A CERTIFIED MECHANIC.. I Have chosen to help those in need, in the past and must not be construed as being a certified technician.

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  • 2 weeks later...
  • 3 months later...

Hi there. I've owned my '86 HCI for 17 years. I've done nearly all the work myself, including an engine rebuild.

And this is my first post here...

Yes, a bad fuel pump will blow one of the 15A fuses. There is a device that is located above the passenger-side fuel tank (labelled "Pektron Derby" - related to the famous "Pektron Inverter" no doubt) that senses the current flow to the fuel pumps. If either pump fails to draw current, the device will shut off both fuel pump relays when above 2,800 RPM. This prevents a lean condition in a turbo car, which can melt pistons.

The device also cuts off the fuel pump relays above 7,000 RPM.

How do I know this? Mine seems to have broken. The fuel pumps are both drawing adequate current, but the Pektron box is confused.

For now, I've forced the issue by grounding one of the relay control leads. (The Pektron device normally grounds the control wire. To shut off the fuel, it opens the circuit.)

Unfortunately, my quick fix also disables the 7,000 rpm cutoff. Maybe I'll build a custom circuit to sense 7,000 rpm, but for now, I'm living dangerously. Whee!

But yeah, nanardos' symptoms definitely pointed to a bad fuel pump. With both replaced, his car should be golden.

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