88HC engine in 83TurboEsprit, vacuum and ignition setup?

[Rolf 28]

Owning a 83 Turbo Esprit with 88HC engine with domestic specification since April this year, it is time to figure out if the installed setup has to be changed.

Problems:

Backfiring downhill with no throttle

Engine stalling / weak acceleration when pushing the throttle hard, with boost

Things already found:

Ignition: Lucas distributor without vacuum capsule is installed (from the LC engine)

Vacuum: Very simple setup with nearly no parts from the HC setup, need to compare with LC diagram to check if it is the LC type vacuum

One circuit connects the fuel pressure regulator with the two carb inlet ports.

Second circuit connects plenum vacuum port, front carb vacuum port, a switch and the vacuum chamber for heater control directly together.

Not sure what is exactly "wrong", because I do not have the Service Notes Engine Managment for the LC engine, only that for the HC type.

Could someone help me with the pages?

Has somebody experience with this kind of partial change from LC to HC engine?

Is it possible to run the HC with the LC setup with good performance?

Rolf

[AJay 1]

Hi Rolf

Contact Dazman, he has just finished converting an LC car with and HC engine, he will be able to help...

[cly_mitchell 1]

I just so happen top have an 83 TE with a 88 HC, small world. In am running 45mm carbs and HC ingnition that has been modified with a pertronix module and coil. I run a HC clutch and pressure plate. I believe all esprits back fire upon over run and with no cat you should have a flame about two foot long out your arse. If you have no vacuum advance, I would say this is the root of your problem. You may also have a carb problem. Such as they need a re-build or or tuned or re-jet.

How much boost are you running? You need to test your timing as it is different from LC. Dazman is in a current state of conversion and may have some advice for you as well. HC is different from the LC in many ways. Running carbs, no cat, no smog, and 10psi your clutch will barely be able to hang on. Keep in mind you are running on the edge, with no innercooler.

Cheers

Clay

[910Esprit 550]

I run an HC head on an LC block with an LC distributor and '40' carbs. This arrangement runs very well. (including the popping and banging on overrun which I consider an essential feature!!).

My hunch is that the LC distributor is not your main problem, To me it sounds more like some sort of fuel starvation. Try checking your fuel pressure when on boost. (you will need a pressure gauge & Tee piece for this)

cheers Steve 84 turbo

[dazmans3 1]

Hi

Have a look through my Thread S3 Turbo HC Conversion

By the sounds of it your Fuel Presure regualtor is connected correctly, but I am not to sure of the other set up. The LC vac system is very basic in comparision to the HC. It should be Fuel pressure Reg to Carbs, & Plenum chamber to turbo boost gauge.(UK spec car)

The LC engine relies on the Vacuum from the Inlet manifold, which simply should feed the Brake servo & the Vac chamber for the heater controls ect. On earlier S3 turbos is would have been a rail connected to two ports on the Inlet manifold, but on later S3 turbos I ve seen just two ports used independantly.

The HC engine would have had a Vacuum pump. more than likely a Mechanical pump which would have been attached to the engine on the Exh manifold side. My thread explains why the HC engine wont fit into an S3 chassis with the Vac pump.

Do you know what Cards you have, LC has 40s & HC has 45s?

I kept the 45s, so do yours look like mine.

Where is your boost gauge being fed from? on LC engine it should be from Vac port at front of the Plenum chamber, HC,s is looped into Vac system. from under the Fuel regulator.

Where is your Brake servo Vac feed coming from?

As has been sugested, look at your fueling first.

Do you know when the Carbs were last refurbished?

What turbo do you have on there, does it have an external wastegate or integral?

What are you boosting at, LC engine is 0.5, & the HC engine 0.75.

My engine is now finished & running resonable well with good boost, except I still have a slight hesitation on pulling away. need to over rev a bit to compensate. It keeps catching me out. So she's going in to have the Carbs re checked on Mon. I will keep you posted on that one.

Some pictures would be nice. seeing what you've got might help a little

You should be able to download the service notes from LEW. but you can also find the parts CD available there or though Ebay, of course.

Clay: I assume you still have the Citreon Gearbox, with your HC clutch set up, did you keep the HC flywheel with that? & can you remember if it was stepped? I was told If I kepted the HC flywheel ect, then I would not be able to release the clutch to change gear. That was from a repitable speacialist here in Uk.

Daz

Edited December 15, 2007 by dazmans3

[Rolf 28]

Hi AJay,

Thanks for the hint. Have started to read his thread about the conversion. Pretty impressive. Looks like a couple of work to be done in front of me!

Hi Clay,

Small world!

Also running with the 45er carbs, but without the vacuum advance.

As the conversion was done by previous owner in the beginning of the 90s, I dont now about the clutch setup.

Boost is cutting out somewhere above 0,5bar, looks like I have the LC external wastgate turbo setup.

Timing will be checked next spring when swaping the timing belt, have it now in winter storage dry bag because of no space to work on during winter time. Quite cold here close to the alps since october this year.

I will also contact Daz for more infos.

Cheers,

Rolf

Hi Steve,

That encourages me. Heard already that the Lucas dizzys HC type are seldom to find nowadays.

I like the popping too, but was not sure if everything is ok back there.

Fuel starvation can be also the problem due to a not correctly installed (blame me ) surge valve I did in the fuel breather pipe on the lt side, found it shortly before winter storing. Was not sure if it is the only reason. Will check fuel pressure, sounds like one of the easier jobs.

Cheers,

Rolf

Hi

Have a look through my Thread S3 Turbo HC Conversion

Hi Daz,

great thread, appreciate the work done to your beauty.

I need time to figure a couple of your questions out and will reply tomorrow evening.

As a newbie to photobucket, I have to learn how to add pics there and will try to link them into this thread.

Makes sense before going on, its more complicated than I expected it.

Thanks meanwhile,

Rolf

[f1karting 0]

I have an 85 with an 87 HC..

here is my 0.02..based on my experiences.. Jan

Edited February 17, 2008 by matk

[cly_mitchell 1]

Clay: I assume you still have the Citreon Gearbox, with your HC clutch set up, did you keep the HC flywheel with that? & can you remember if it was stepped? I was told If I kepted the HC flywheel ect, then I would not be able to release the clutch to change gear. That was from a repitable speacialist here in Uk.

Daz

[dazmans3 1]

I have a saab blackstone innercooler to install like WayneB did. Are you installing an innercooler or methanol injection? Oops, I hope we are not hijacking this thread.

Hi Clay

Not wanting to take over this thread in partership with yourself, No, I don't intend to put an intercooler or chargecooler on for the time being, no mater how tempting it sounds. Pluss with the gearbox on it's limits as it is.... I think I will enjoy her as is for now. Want to get this hesitation sorted first. I did think about the CO2 levels, but I didn't want to tinker with until the dealer I went to has had a chance to look at. Once thats sorted I will be Rolling road testing her, just to see what BHP she is putting out.

Now back to you Rolf

Daz

[Rolf 28]

I have a saab blackstone innercooler to install like WayneB did. Are you installing an innercooler or methanol injection? Oops, I hope we are not hijacking this thread.

Hi Clay

Not wanting to take over this thread in partership with yourself, No, I don't intend to put an intercooler or chargecooler on for the time being, no mater how tempting it sounds. Pluss with the gearbox on it's limits as it is.... I think I will enjoy her as is for now. Want to get this hesitation sorted first. I did think about the CO2 levels, but I didn't want to tinker with until the dealer I went to has had a chance to look at. Once thats sorted I will be Rolling road testing her, just to see what BHP she is putting out.

Now back to you Rolf

Daz

Hi Daz,

had the reply ready with uploaded pics, pressing uploading button and .... lost.

Will try again tomorrow.

Rolf

I have an 85 with an 87 HC..

here is my 0.02..based on my experiences.. Jan

Hi Jan,

You are right, setup description was partly wrong from me and is quite close to that mentioned in your remarks.

Will show pics and explanation what is inside asap.

Car is on carbs.

I am not familiar with two of your comments:

Dyno session

jetting

Please explain.

Rolf

[Rolf 28]

Attached some pics and a summary of information

[dazmans3 1]

Open questions:

- Is the vacuum switch standard on LC cars? What is it switching?

- TIV connections unnecessary, only used now as a complicated throttle edge port closing?

- Are brake servo and heater control connected to only one common vacuum source? Sounds dangerous for breaking if I loose a vacuum hose somewhere under the dash

Hi Rolf

I have attached a photo, taken form the Parts Manual of early stevens car with HC Carb engine.

As far as I am aware there is no Vacuum switch on the UK spec LC engined turbo cars.

The switch is suposed to aid cold starting/running. It should be connected to a temp sensor located on the Alloy water pump to chasis water pipe (Big U shaped pipe at back right side of engine). From what I gather it opens the Vac network to the main Vac supply untill the engine reaches running temp.

You can see it on the bottom Lt of the photo next to the Boost sensor & Over boost sensor.

Any idea it you have an Over Boost switch connected. I would consider this essential. I have left the mechanical version on mine from LC engine. It would be located under the fuel regulater if you have, But I couldn't make one out in the photo.

I noticed, on the alloy water pipe, one of two sensor ports looks like its blocked off, I can't make out if the other is. Can you tell me if there are, or if they have a temp sensor switch? It's one of these that is needed to open/close the Vac switch.

I have taken the Vac switch out of my Vac system, as was told it's not needed. However, that hesitation I mentioned I had. well, when my engine is fully warmed up, it's not noticable.

Those Vac pips look a bit worn. maybe they need replacing. I found, when experimenting with the Vac set up on mine, I was using old pipes at first to gauge lenghts & conpatibility etc, my Carbs where very sensitive to leeks.

I think your 'Q' about TIV should be answered in Photo.

If you have no boost, then maybe your Wastegate Dump Valve could be stuck open. this is common, though normally, with the external fit, they stick in closed position.

I would prefer seperate Vacuum sources for Brake servo & heater controls. That is how my LC engine was set up, But I know that the early LC turbo engines had a metal rail that had two Vac outlets, one for brakes, & one for heater bits, but also it had two feeds from the inlet manifold.

Hope this helps a little

Daz

[f1karting 0]

COMMENTS ADDED.. J

Therefore new description of vacuum pressure piping setup as installed, details as far as available on the pics below.

- The two carb inlet ports (used also for balancing) are connected together and the

pipe is ending in a switch. SORRY CANT EVEN GUESS WHAT THAT COULD BE USED FOR

- Air intake plenum, connector on the front plate. Is divided to three connection

points. One to the fuel pressure regulator (FPR), one to the thermal ignition valve

(TIV) upper port, one to the front through the chassis, has to be the connection

for the boost gauge, but not verified. THE TIV IS A VAC ADVANCE CONTROLLER THAT NORMALLY ROUTES VAC TO THE DISTRIBUTOR ADVANCE CAPSULE DURING COLD STARTS/RUNNING.. IT HAS SOME PROTECTION IN IT SO THAT IN THE EVENT OF A TIV FAILURE THE ENGINE WILL NOT BE SUBJECT TO FULL TIME VAC ADVANCE , (LEADING TO DETONATION) .. SINCE YOU HAVE NO VAC PUMP OR CAPSULE ITS POINTLESS TO HAVE THE TIV AND PERSONALLY I DONT THINK IT IS NEEDED FOR COLD STARTING UNLESS YOU LIVE IN A REALLY COLD CLIMATE.

- Throttle edge port to lower port of TIV. I WOULD CAP OFF THE EDGE PORT AND LOOSE THE TIV

- TIV: middle port pipe blocked out of sight of the pic, as there is no capsule. TIV

connections imho sensless. YES

- vacuum source for vacuum chamber (heater control) and brake servo: starts at

rear carb intake port, front port is closed (looks like welded, not a good pic from

this area), so seems that both are connected to only one feed. THAT IS NOT A GOOD SITUATION UNLESS YOUR CAR HAS A VAC STORAGE CHAMBER.. OTHERWISE UNDER BOOST, VAC WOULD BE LOST AND YOUR HEATER AND BRAKE BOOSTER WILL NOT MAINTAIN VAC FOR LONG.. I WOULD SEE IF YOUR CAR HAS HAD A VAC CHAMBER ADDED THAT STORES VAC FOR THE HEATER AND BRAKES. IF SO, HOPEFULLY IT HAS A CHECK VALVE THAT CLOSES ON BOOST SO THAT YOUR VAC CHAMBER CAN HOLD WHATEVER VAC IT HAS GAINED DURING IDLE PERIODS. IF NOT, MAYBE SOME RE-ENGINEERING IS IN ORDER. I CANT TELL YOU HOW MUCH VAC CAN BE DEVELOPED AT IDLE, BUT IT SURE DOESNT TAKE LONG FOR BOOST TO DEVELOP.. EVEN AT LOW THROTTLE POSITION.. SO HOPEFULLY THERE IS ENOUGH RESERVE IN ANY CHAMBER TO DO THE JOBS IT NEEDS TO.

Intermediate summary:

Clearified items and actions:

- Dizzy without capsule is not the problem as Steve is describing he is running with that kind of setup quite satisfied, not more than 18

Edited December 19, 2007 by f1karting

[Rolf 28]

Hi Daz, attached the answers!

Hi Rolf

I have attached a photo, taken form the Parts Manual of early stevens car with HC Carb engine. THANKS, WELL EQUIPPED WITH 87 ONWARDS DOCUMENTATION, ONLY THE LC ENGINE MANAGMENT PAGES I MISS.

As far as I am aware there is no Vacuum switch on the UK spec LC engined turbo cars.

The switch is suposed to aid cold starting/running. It should be connected to a temp sensor located on the Alloy water pump to chasis water pipe (Big U shaped pipe at back right side of engine). From what I gather it opens the Vac network to the main Vac supply untill the engine reaches running temp.

You can see it on the bottom Lt of the photo next to the Boost sensor & Over boost sensor. CLEAR, BUT NOT NEEDED AS I DO NOT HAVE THE DIZZY WITH THE CAPSULE

Any idea it you have an Over Boost switch connected. I would consider this essential. I have left the mechanical version on mine from LC engine. It would be located under the fuel regulater if you have, But I couldn't make one out in the photo. BOTH NOT INSTALLED, SEE PIC. IS THE LC TYPE RELEASING BOOST IN CASE OF WASTEGATE FAILURE OUT OF THE PLENUM? WHAT SIZE OF HOLE IS IT?

I noticed, on the alloy water pipe, one of two sensor ports looks like its blocked off, I can't make out if the other is. Can you tell me if there are, or if they have a temp sensor switch? It's one of these that is needed to open/close the Vac switch. BOTH ARE BLOCKED, AS DESCRIBED ABOVE THE SYSTEM RUNS WITHOUT CAPSULE AND THEREFORE VAC SWITCH NOT NEEDED HERE.

I have taken the Vac switch out of my Vac system, as was told it's not needed. However, that hesitation I mentioned I had. well, when my engine is fully warmed up, it's not noticable. MAYBE YOUR UPPER TIV PORT IS NOT WORKING IN COLD CONDITIONS BELOW 70

Edited December 19, 2007 by Rolf

[cly_mitchell 1]

Just a point, but rolf, you don't have a pop off valve. Do you have a BOV somewhere I can't see. I know the fuelies have electronic gizmos. I think you have a F.I. plenum. Not real sure about this set up. Jan......Daz do have some input here?

Cheers,

Clay

[USAndretti42 315]

Are your accelerator pumps working? They squirt fuel into the engine when you open the throttle so the engine responds well to the throttle. The diaphragms in the pumps can split so they stop working. May be worth checking.

[f1karting 0]

Just a point, but rolf, you don't have a pop off valve. Do you have a BOV somewhere I can't see. I know the fuelies have electronic gizmos. I think you have a F.I. plenum. Not real sure about this set up. Jan......Daz do have some input here?

Cheers,

Clay

Too true... good observation... no BOV! I think Rolf should add one in.

I am not familiar with this procedure, but think I find a possibility for that kind of test run. Should know what exactly is 12.5:1 AFR (unit?) and where is it measured?

Rolf

THE AIR FUEL MIXTURE WOULD BE READ BY AN O2 SENSOR (LAB QUALITY) INSERTED INTO YOUR TAILPIPE.. THE O2 SIGNAL WOULD BE CONVERTED INTO AIR/FUEL RATIO (hence AFR) READINGS AND PLOTTED BY THE DYNO SOFTWARE DURING A 'RUN".

FROM THIS PLOT YOU CAN DETERMINE WHAT JETTING ADJUSTMENTS NEED TO BE MADE AT WHAT RPM. AND THAT IS WHERE THE TRICK IS.. KNOWING WHAT JETS TO CHANGE AND BY WHAT AMOUNTS. IVE GOT A REASONABLE SENSE OF JETTING WEBER AND DELLORTO CARBS FROM YEARS OF PLAYING WITH THEM, BUT THE DYNO SESSIONS IVE HAD HAVE BEEN VALUABLE LEARNING TOOLS FOR ME IN UNDERSTANDING THE RELATIONSHIPS AND EFFECT OF VARIOUS COMBINATIONS.

FROM THE AFR READING AT IDLE, YOU CAN NAIL THE IDLE MIXTURES, YOU CAN SEE PUMP JET CHANGE EFFECTS IN THE ACCEL ENRICHMENT PHASE, AND YOU CAN SEE THE RELATIONSHIPS AND EFFECTS OF COMBINATIONS OF MAIN JETS AND AIR CORRECTORS.

THE IDLE CIRCUITS FUEL/AIR COMBINATIONS ARE HARDER TO TUNE ON THE DYNO.. IT SEEMS THAT FEEDBACK FROM DRIVING THE CAR WORKS WELL. MIND YOU, I HAVE FOUND, CONTRARY TO POPULAR BELIEF, THAT THE IDLE JETS SEEM TO HAVE LITTLE EFFECT ON MIXTURE STRENGTHS OUTSIDE IDLE/PART THROTTLE /CRUISE OPERATIONS.

ONE THING I HAVE DISCOVERED IS HOW THE PUMP JET PUSHROD SETTINGS CAN BE TWEAKED TO IMPROVE THE 'OFF THROTTLE>LIGHT ACCELL'' DRIVABILTY SUCH AS DURING THE INITIAL ROLL OFF FROM FROM A STOP. I HAD A NASTY RICH STUMBLE ON LIGHT THROTTLE APPLICATIONS, THAT I ELIMINATED BY ADDING CLEARANCE IN THE PUMP TAKEUP.

SORRY FOR ALL THE BOLD TEXT...

Edited December 19, 2007 by f1karting

[Rolf 28]

Just a point, but rolf, you don't have a pop off valve. Do you have a BOV somewhere I can't see. I know the fuelies have electronic gizmos. I think you have a F.I. plenum. Not real sure about this set up. Jan......Daz do have some input here?

Cheers,

Clay

Hi Clay,

Yes, there is no mechanical BOV installed. After finally clarifying this matter yesterday, I have checked the Service Notes and the Parts List for the dump valve Daz has installed. Looking through them, I found that it is not an easy retrofit to my intake plenum.

As I have still the unknown vacuum switch, I rechecked the different vacuum setups described and found at item 43.03A for 87 hc domestic specification, Pos. 17 in the Parts List, an overboost vacuum switch from Lotus, directly connected to the carb balancing ports, same setup on my engine.

Looks like this is my electrical overboost switch, electrical cut off fuel pump or ignition. Will check next time when engine is running with disconnecting one of the cables.

Cheers,

Rolf

Are your accelerator pumps working? They squirt fuel into the engine when you open the throttle so the engine responds well to the throttle. The diaphragms in the pumps can split so they stop working. May be worth checking.

Good point Trevor,

Could be a to lean mixture due to that. When pushing throttle hard, engine is stumbling excessive. Similar behaviour as described from Jan with his former to lean jetting on the carbs I guess.

Never had a problem to reach high revs or high speed, but not on a fast throttle push.

Could the 5% Bioethanol (hardening and braking of some sorts of flexible plastics possible) added to fuel in Germany be the fast death of a diaphragm?

Would that mean that the carbs are leaking below a broken/spitted diapragm only during fast acceleration, but not at normal idle or moderate throttle push?

Would a not Turboproof sealing kit (refurbished by a non Lotus garage in May 2005) for the carbs have the same effect?

What areas are different sealed on Turbo carbs than on N/A type carbs?

Rolf

Jan,

Now I have an idea about it!

Will see where I find a roller type test stand to get the meassuring. Remember that I have seen a dyno diagram in your thread about air intake length shortening. This will help searching in springtime when bringing her back to road. No worries about the bold text. Thanks, Rolf

Edited December 19, 2007 by Rolf

[cly_mitchell 1]

Interesting. I think the overboost cut off switch will only work on a FI. At least that is what I understand. When you change gears, I think you will be in a position of over boost. I think this is a bad thing. It could be possible to install a BOV between the plenum intake and the turbo. A BOV is different than the pop off that is factory install. The factory pop off only vents off pressure when the plenum pressure get above 15 psi, where as a BOV will vent at any point you back out of the throttle. I don't do that so I don't need one. B) Something to think about.

HMMM... I just thinking out loud here, but that maybe a reason you have that dissy without and vacuum advance. If your boost spikes it could disrupt the diaphram. HMMM??????

Guys???

Cheers

Clay

[dazmans3 1]

Rolf

Just seen your photos on your Avitar. can only see front end, but yours looks like it has the same alloys as was fitted to the St Topez convertable turbo esprit. it also looks the same colour. Can you confirm? I know a little history about the St topez, as I almost bought it in back in 96.

Daz

[Rolf 28]

Rolf

Just seen your photos on your Avitar. can only see front end, but yours looks like it has the same alloys as was fitted to the St Topez convertable turbo esprit. it also looks the same colour. Can you confirm? I know a little history about the St topez, as I almost bought it in back in 96.

Daz

Daz,

Just learned how to put a picture to the avatar

Yep, it is the St. Tropez.

As I was searching for a TurboEsprit already for 1,5 years, preferably in blue, with hc engine and removable sunroof, this one was more than perfect.

Have seen it first in Jeremy Waltons book, liked the look always since.

Could you please send me a pm for the history?

Rolf

[dazmans3 1]

Wow, you lucky person you. I was looking at that car about 10 yrs ago when I was looking for an esprit. I have PM ed you the story.

Daz

[matk 17]

Donnington this year...........

[cly_mitchell 1]

Rolf,

I am a little concerned about your carb set up. The vacuum line comming of the top of the carbs are strange to me. I get the feeling that these are not turbo carbs. Mine are blanked off and sealed with epoxy. Your spacers between the manifold and the carbs don't seem right either. I will not pretend to know everything about these cars as there are many varients. The biggest concern I have now is that if your carbs are not turbos you could have a fire upon boost. And because you have no overboost protection your carbs could see boost welll over 15psi. I would really have these things checked out before I went much further. Fire is a posibility with these cars, be prepaired. Some of us have supression systems, others just hand held units, and others just run like hell system of defense.

Cheers

Clay

[Rolf 28]

The vacuum line comming of the top of the carbs are strange to me. I get the feeling that these are not turbo carbs. Mine are blanked off and sealed with epoxy. Your spacers between the manifold and the carbs don't seem right either.

Clay,

would you post a picture of your setup and also the vacuum lines running around your carbs, would be quite interresting for me to check the differences (epoxi blanked vacuum ports, spacers to manifold) you mentioned.

The biggest concern I have now is that if your carbs are not turbos you could have a fire upon boost. And because you have no overboost protection your carbs could see boost welll over 15psi.

Don