MY BOOST GAUGE IS GOING OFF THE CLOCK - HELP!

[Luke - the elanimal]

Hi all,

i had my new peco exhaust system fitted yesterday (its awesome) but now my boost isnt being limited and shoots straight to the top of the gauge!!

as much fun as this is i dont want to blow my engine up
just wondered if anybody knows what the problem is and how to fix it please?

if indeed it is a problem?? maybe the car can hack it safely??

any info i can give to the mechanic who said he may need it for 2 or 3 days!! would be greatly appreciated and may hopefully save me some money.

look forward to hearing your replies guys.

[Russc]

What`s happening when the boost goes up, is the engine light coming on and the car feeling like it`s lost power??

If so then it sounds like you have boost creep or a stuck wastegate.

Boost creep means porting the wastegate and stuck wastegate can be fixed by the old "wastegate wiggle"

[Luke - the elanimal]

havent noticed an engine light coming on (but i have only driven it in daylight)
It doesnt seem to have lost any power though, if anything it seems much quicker.
hope i can get a few ideas to tell the mechanic so he doesnt try and make it something its not in terms of payment

[Benmac]

If your hitting the fuel cut due to boost creep believe me, you'll know about it.

Engine suddenly coughs and momentarily loses all power and the engine light comes on.

It does sound like boost creep just that you haven't actually got so far as the fuel cut yet.

First thing to try is the wastegate waggle, lots in the archives on here about it. This is a 5 minute job with a set of molegrips. If that doesn't do it then porting the wastegate is the way to go - something I want to do at some point on mine.

[Luke - the elanimal]

just spoke to Dave at Peco and he said maybe its just that my dial has become faulty (so i'll check that later)

The wastegate wiggle people talk of, does this mean moving the actuator rod? if so this was done 2 weeks ago as i had a new end welded onto my rod as it wasnt working when i got the car, so im thinking that should be ok.

Dave said that getting the wastegate ported is a big job

Does anyone know how much i may get charged? (uk)

Also will this purely solve the problem (all being well) or will it give me performance gains?

Really hoping i dont experience this engine cutting out thing it sounds bloomin dangerous, could it not cause a big accident if the car is hurtling along then suddenly cuts out?

I had a quick look this morning at my boost gauge and noticed it was sat at a quarter of the way up even when the car was idling (not moving but engine on) is this normal or would this suggest that maybe dave was right and that the dial has gone a bit funny overnight since the exhaust was fitted?

As soon as i get one problem sorted i seem to have another to be getting on with, hope this doesnt carry on forever and that i actually get to enjoy the car soon without fear of it blowing up or cutting out on me

Im losing my faith lol

The car does sound awesome tho with the peco system and definitly feels quicker.....just dont want to be scared to drive it kind of thing.

[tweetdriver63]

...i had a new end welded onto my rod...

That must have hurt!


Sounds like a subject for a different thread

[Sy V]

You don't mean that the dial goes straight up to the limit on start up do you?

[Russc]

Do you have a FCD on your car at all? if not then the car would protect itself if on full boost and cut the fuel (and the engine light comes on)

From what i`ve seen elsewhere the boost gauge is said to be cr@p and unreliable

Could well be your gauge that`s not working well.

[Monty]

Yep u`r going to get more boost/power, thats the whole point with a bigger bore exhaust, but it does sound like u`r boost gauge is out. Have u got it chipped? With the Peco u might get 0.7 to 0.9 bar boost, as long as u don`t have a FCD (as mentioned above) and don`t hit the fuel cut u`ll be fine. Try cleaning the connections to the boost transducer

[tweetdriver63]

You don't mean that the dial goes straight up to the limit on start up do you?

I thought that, too, when I started reading the thread, thinking about the ground connector on the sending unit (I know that's not the correct name for the part, but it escapes me), but then I read where he said the guage goes to 1/4 with the car just sitting in idle.

[Luke - the elanimal]

...i had a new end welded onto my rod...

That must have hurt!


Sounds like a subject for a different thread

[Luke - the elanimal]

You don't mean that the dial goes straight up to the limit on start up do you?

Hi...no its only when i accelerate hard that it shoots straight to the top of the gauge.

I dont think its been chipped as the 1 lady previous owner would have mentioned it and theres nothing in the paper work etc, also it has a full lotus service history and again i think there would be some mention of a chip somewhere in my paperwork. . . . . though i do want it chipping at a later date.

havent had engine cut out happen yet, and hope i dont as it sounds dangerous

if its a dodgy gauge then it seems very odd that its happened in the last day or 2 since having the system fitted as it was fine before i had that done.

[philip_sloper]

The guage should not show any boost at idle, so it must be misreading. It could be a faulty guage, but it could also be the transducer, which is in the engine bay on the offside.

[Benmac]

Whilst it causes a bit of a 'WTF?' moment the first time you feel the fuel cut its not really dangerous as it really is momentary. The light then stays on for about 10 seconds and power is limited.

Whilst not ideal its probably safer than the engine going boom.

I'm certainly no expert but the gauge does sound a bit weird. Easiest thing to do will be to clean up the contacts on the trasducer. Its the cylindrical thing mounted on the offside inner wing in the engine bay in an orange rubber boot. Take the connections off, particularly the earth and clean them up. Got to be worth it before starting on more involved remedies.

[Doug]

dude, the ground wire to the boost gauge transducer in the engine bay has come loose -- find it and wiggle the black wire -- it should be loose and then tighten it and the gauge should be okay again.

the pounding to the car to get the old exhaust off may have made the screw a bit loose -- this is an extremely common occurance

once the gauge is behaving then see if all is well

if the car is driving well and you are not hitting the boost cut then don't worry

but the needle registering at idle and going above the end is diagnostic of the bad ground wire . . .

[nitroman]

Look man, your gauge & the "safety" (the MAP sensor which communicates with the ECU to shut-er-down) run off completely different sensors. If your engine isn't getting a HARD shutdown then it's your boost gauge or input to it that's whack. Being 'pinged', gotta work!

[rip]

Luke - Have you run Elanscan yet. That will tell you what boost you are really getting.
Why don't you keep track of the East Midlands gang? We met up near Peterborough yesterday so you missed out on that I'm afraid. You will feel welcome because Gary takes most of the abuse!
Our thread may be swamped with banter, but out meets are highly enjoyable. If you meet up with us at our next gathering, we can scan you Elan then to find out what is really going on.
I am using Elanscan to do some private research into 95 v 97 petrol so my laptop virtually lives in Blue.
Your boost gauge is no better than a rough guide and its accuracy is very questionable at best.

[dapinky]

Here's the benefit of my wisdom, gained through not reading posts properly, and doing it my own way

When i had the exact same symptoms, i cleaned the transducer spade connectors and re-fitted them.

No change.....

i checked the earth wire - loose at the other end!

tried to tighten up screw....kept going round and stayed loose....

...had a 'brainwave' and cut wire - running it directly to chassis earth....

BIG MISTAKE

Found out that there are about 3 different earth voltages on an elan, some positive, some negative and some zero.....you need to have the right one for the right thing.

(I'm not an electrical engineer - i just know how to use a big hammer and a spanner (wrench) set)

Easy fix, drill a 3mm hole in the transducer bracket, attach earth wire to that hole with a self tapping screw.

Job done....no problems since.

[Sy V]

Yep, that's why I asked. Transducer earth wire is the problem.

[GeoffSmith]

Found out that there are about 3 different earth voltages on an Elan, some positive, some negative and some zero.....you need to have the right one for the right thing.

Interesting topic for discussion methinks.