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lotusespritse

Trying to help a friend with a engine cut out problem

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I am an ex-SE owner, and a new V8 owner, so I don't have any experience with the '86 model to help a good friend.

His car is quickly becoming a barn find because he has had an issue with the engine cutting out over 3000 rpms and he doesn't know what to do. He tried having local mechanics work on it in Houston, but they couldn't fix it (not clear they were Lotus experts in any way), so he gave up.

I am trying to motivate him to get the car back on the road.

Here's the original problem: He took the car for a timing belt change, which seemed to go ok, but afterward it developed an engine stumble when trying to do more than 3000 rpms while driving. The car starts fine, it idles fine, it feels good up to 3000, and then bogs at anything over that at any throttle level.

He found the diaphram in the wastegate ripping, so he had it replaced and it kept ripping. He wasn't sure if he was getting old stock, or if something else was wrong. In the end, it just sat covered.

Can anyone please give some direction on how to fix the problem to help get him back on the path to a driveable Esprit. It's a gorgeous pearl white with blue interior that's well preserved in stock trim.

Thanks!

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Star Motorcars used to be the best lotus resource in Houston, but not sure what they are doing these days. They used to race a scca europa out of their shop.

As a start, confirm the cams are in time, then check fuel and ignition systems...

Brian

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Star lost their "star" mechanic and now no one goes there with their Esprit. I think they have even told the Esprit owners they are no longer welcome. So that's a no go.

So if the cams are out of timing, that could cause that sort of over 3000 rpm issue? I would have thought the idle and below 3000rpm would be affected if the cam timing was out.

Edited by lotusespritse

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Isn't there a spring inside the distributer that adjusts timing around 3000 RPM? Also his car has carbs, but I would think it's a timing issue, not a fuel supply issue.

Not that I know anything at all. :-/

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I'd definitely consider fuel delivery to the carbs. What's the fuel pressure setting? How old are the tanks? When was the filter changed?

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Hi, I'm Joe with the fuel injected 86 turbo Esprit that Philip is helping to get back to normal.

The problem is that the engine cuts out at about 3000 rpm just like it does with when it reaches the turbo over boost limit. When I let off the thottle it runs normal again below 3000 rpm. The reason that I knew about the turbo over boost engine cut off, was before I got the car worked on, it ran find around town, but after 20 min. on the highway it would trigger the over boost cut off when I accelerated.

So, when the shop put in a new wastegate diaphram, it blow out after 10 min on the highway, then the 2nd one had the same problem. The shop didn't know what else to do and gave up then refunded the cost of that job. It sat for serveral months, then it started the 3000 rpm cut out problem and after a new fuel pump, it still has that cut out problem. It feels and sounds like the ignition cuts off.

Any ideas for a fix?

Thanks

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Hi Joe,

My first bet would be to check that both fuel pumps are running,if one of the two is dead, I think it would have a hard time getting to high revs.

But that does explain your overboost condition, for that, I'd make sure nobody installed a cap on the lower portion of yor waste gate, it's a threaded port, somebody might have being tempted to cap it off.

If you rev it when the car is not moving can get over 3000 rpm (getting there slowly without boost)?? If you can it's not your fuel.

I'd also try to push the overboost fuel cutoff button on the top of the rear relay panel while revving it just to see if it duplicates what you have while driving it.

Keep us posted and you're at the right spot to fix it for good!

This is a superb example of what a forum should be!

Luc

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Luc, I think all of you have some good suggestions. I will check for a cap in the wastegate and the fuel cut off button in the relay panel. I think that I have 2 seperate problems with the over boost cut off and the over 3000 rpm cut out. Maybe they joined forces against me now. If the engine with no load is slowly rived to 3000 rpms it will still cut off and then come back on when I let off. I don't know if it is fuel or ignition that cuts it off, but it is abrupt and the engine feels strong while accelerating up to that cut off rpm. The start up and idle is normal.

Jonathan, thanks for pointing out the distributer timing spring.

.

Gary, this 86 yr. I think was the first year of fuel injection, I need to ckeck the filter, and the fuel pressure. The tanks are original, thanks.

This is a good list of things to ckeck out, the car has been unused for serveral months now, I just need to get me and the car going again.

Joe

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I'm with Brian....Please, oh PLEASE, check the cam timing!!! I had exactly the "no power above 3000rpm" symptoms you describe, and it turned out that the inlet cam had jumped teeth....I discovered this when I bent all 8 inlet valves!! So turn the thing to TDC for no.1 on the firing stroke and check that the cam dots point at each other, before you do anything else.....once you are certain the cam timing is correct, then start on the fuel and ignition etc.

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The button on top of the relay box is the inertia switch, which shuts fuel off after a crash to prevent fires. If the car runs at all then the switch is in the proper position.

In addition to everything else already suggested (a HEARTY +1 on verifying the cam timing, even though that shouldn't cause the stated symptom), have you ensured that the wastegate is free to move? I've heard of them getting stuck. Also make sure that the 'gate is properly plumbed: a metal tube running from just downstream of the turbo to the upper half of the actuator housing. Mine was mis-plumbed by the previous owner in some cockamamie attempt to produce variable boost and it caused a symptom similar to what you're experiencing. You can eliminate the overboost switch by unplugging it, putting a jumper across the two wires, then carefully revving above 3000 with one eye on the boost gauge.

As dumb as it sounds, make sure that the ignition timing is correct. This may have been disturbed during the cambelt-change, since the distributor shaft is turned by the cambelt. The US-spec is 15 BTDC, but many cars run much better around 21-22 (mine for example, which feels 'asleep' and stumbles badly around 4500 when set to 15). Also make sure that all the small-diameter plumbing is intact, especially the two that connect to the distributor's advance diaphragm.

You may also want to check that there are no intake leaks. Some of my car's stumbles disappeared after I changed all the intake gaskets, and I do know that I had some leaks from the gasket between the manifold and head as well as from some of the eight gaskets on either side of the throttle bodies.

Good luck and keep us posted...

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Oups! sorry about that button, not part of the big guns yet!

And I have to agree that everything starts with the basics...like timing.

By the way Ben, if you're still looking for leaks (you probably have changed these already...) the injectors o'rings are another area to look at, nice spot for unmetered air to get in. (Same as GLI, GTI 86-87 air shrouded, real cheap for a kit)

Luc

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