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Boost doesnt rise above 0.4


Oroboros

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Hi guys,

First off, I apologize for being a complete noob, but I am learning on the fly.

I have recently disconnected the battery and was doing the re-learning of the ECU drive today.

I noticed that when accelerating, the boost would never go beyond 0.4 and at the same time, around 4000 rpm or so, the engine would start stuttering, so I let off the gas and it behaves normally under 4000 rpm.

My question is; is this normal during the re-learning phaze or is this another problem?

It was a rainy day, and my car doesnt have the engine cover, which Ive ordered. So I am thinking it might be the spark plugs, but any advice would be very welcomed.

A few other issues I have is the abs tell tale light keeps flashing, and the fuel tell tale behaves erradically, going on and off and it seems to be random.

In advance, thanks!!

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Hi,

Can't say if boost issue is related to ECU re-learning, but I would not think so. I've had the battery disconnected a few times and had no boost limitation before, during or after re-learning period.

One easy thing to check re: lack of boost is the wastegate rod to see if the wastegate does not get stuck open. I understand the rod mechanism does age over time (spring wear, dirt collection, etc.) and the Turbo chamber may require a good clean-up too.

Regarding ABS flashing light, have a look in the Brakes section, you'll find lots of posts on the matter and several (not many) likely root causes. If you don't have it, download the 'espritmon' software to hook a PC to the ECU and ABS controller. You should then be able to collect error code(s) and verify brake system behaviour too.

Edited by RV_ABZ

1980 Peugeot 504 Coupé V6Ti

2000 Peugeot 406 Coupé V6SE

1996 Lotus Esprit S4s

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  • Gold FFM

Boost limitation and stuttering may be related to a false temperature reading. Does your ABS light go out normally after starting and before moving off?

British Fart to Florida, Nude to New York, Dunce to Denmark, Numpty to Newfoundland.  And Shitfaced Silly Sod to Sweden.

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The ECU can't control or limit boost below .65 bar. so if your boost is below that then there is something else wrong like an exhaust blockage, bad turbo, bad spark, blocked air intake, etc...

Definitely not normal for learning phase.

And does sound like spark plugs or wires. may be due to water around the plugs. I would start with some di-electric silicone grease in the plug wire boots.

Travis

Vulcan Grey 89SE

 

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The ABS light and the Check Engine light both light up and go off normally before setting off, will inspect the spark plugs and check for water getting in. As for the wastegate, will check it after the spark plugs, as everything was normal last week when I had her out for a test run. We have had a lot of rain in the past week so I am assuming it is the spark plugs, as I have heard it can be an issue when the engine cover is off.

Edited by Oroboros
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Did another test run, and the ABS light doesnt flash anymore. The boost goes up to 0.5 on the needle exactly flat out, and doesnt go beyond though.

Come to think of it, I couldnt hear the wastegate operating while lifting off either.

Edited by Oroboros
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Temperature, all day long.

Sit on the side of the road, let the car get properly hot so that the fans are kicking in (or use Freescan/Espritmon to see what the ECU is seeing exactly) and then give it more than 95% throttle (also use Freescan/Espritmon to check your TPS and that you're getting full throttle travel.)

88 Esprit NA, 89 Esprit Turbo SE, Evora, Evora S, Evora IPS, Evora S IPS, Evora S IPS SR, Evora 400, Elise S1, Elise S1 111s, Evora GT410 Sport

Evora NA

For forum issues, please contact the Moderators. I will aim to respond to emails/PM's Mon-Fri 9-6 GMT. 

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Roy,

Are you sure the boost is at .5 bar or is it just in the middle of the gauge?

If it is just in the middle of the gauge, then that is pretty much .65bar, and that would agree with a coolant temperature issue. as Bibs suggests.

If the bar is below .65 that that has to be an obstruction, or misfire, or boost leak, or something like that, and is not ECU interference.

My 89SE gauge looks like this btw (I don't remember what the S4 boost gauge looks like or if it is different)

P5140303.JPG

Travis

Vulcan Grey 89SE

 

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It was at 0.5 but is now up to 0.65 after my latest test drive, the boost gauge is similar, but it has 0.5 labled on it aswell, and now it went past to the middle point, so Im guessing thats 0.65 I noticed that the temperature gauge on the lower left side, was almost touching the red. As this is my first experience with the esprit, I have yet to learn a lot. Amongs other things the correct temperatures for operation.

I dont have freescan or espritmon yet, but will definately get it asap.

Edited by Oroboros
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If the needle is left and touching the red that's your oil pressure gauge. Water temp is the gauge on the right of the dash. The ECU will limit boost to 0.65 bar if the car is less than 72C to protect the cold engine, that's what you're seeing here.

88 Esprit NA, 89 Esprit Turbo SE, Evora, Evora S, Evora IPS, Evora S IPS, Evora S IPS SR, Evora 400, Elise S1, Elise S1 111s, Evora GT410 Sport

Evora NA

For forum issues, please contact the Moderators. I will aim to respond to emails/PM's Mon-Fri 9-6 GMT. 

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Sorry bibs, forgot to check which hand I write with :P I meant the right side (Facepalm). I mean the water temp, is nearly touching the red. Can this have the same limiting effect, and can it then mean there is a chargecooler issue?

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Yes, a high coolant temperature will also cause the ECU to limit boost to .65bar.

The ECU uses a different temperature sensor (under the intake manifold) than the gauge on the dash (brass sensor with a single wire at the thermostat) so you can check them against each other using freescan or Espritmon on a laptop PC.

If they agree, then your coolant is too hot. If the ECU water temp is normal (~80C) and the dash shows hotter than that, then you know need to find out which is correct.

Travis

Vulcan Grey 89SE

 

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It's a free download from here in the ECU section :)

88 Esprit NA, 89 Esprit Turbo SE, Evora, Evora S, Evora IPS, Evora S IPS, Evora S IPS SR, Evora 400, Elise S1, Elise S1 111s, Evora GT410 Sport

Evora NA

For forum issues, please contact the Moderators. I will aim to respond to emails/PM's Mon-Fri 9-6 GMT. 

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88 Esprit NA, 89 Esprit Turbo SE, Evora, Evora S, Evora IPS, Evora S IPS, Evora S IPS SR, Evora 400, Elise S1, Elise S1 111s, Evora GT410 Sport

Evora NA

For forum issues, please contact the Moderators. I will aim to respond to emails/PM's Mon-Fri 9-6 GMT. 

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