flat at 120mph, 5500 revs?? anoying me now!
 

changed plugs recently, new fuel filter walbro fuel pump, thrash through gears and drives fine> get to 120 everytime in 5th gear and dies goes flat and have to take my foot off? why

second problem is i start car up now and revs at 1500-2000 for a few mins, when warmed up also revs are sitting at zero but car seems to be idling ok when warm

PLEASE HELP ME IM GETTING ANNOYED AND DONT WANT TO PAY GARAGE ANY MONEY TO LOOK AT IT

What year is it, UK or import, was it fine before or has it always done this?

There may be a speed limiter on it if it was an import.

sounds an awful lot like a speed limiter

NO NOT ALWAYS HAS SEEN 140!!

IMPORT 1995

will it go over 120mph if u take it steady and not on full boost?

fuel cut?

What you mean by "It dies" it should be pulling fairly sloqly form 120 in 5th if its standard so dont expect it to fly round to 140 ish. Are the revs cutting? or is the engine physically hesitating (missfire/boostcut)? Have to explain it a bit better

FIRST OF ALL I MUCH APPRECIATE THE ANSWERS THANK U. NOT TRIED TAKING IT STEADY AND TRYING TO GO FASTER. I CANT 100% EXPLAIN ITS STRUGGLING LIKE A MISFIRE I SUPPOSE HOW DO U EXPLAIN? SOUNDS AND FEELS AWFUL SO HAVE NO OPTION BUT TO LET OFF!

just try taking it steady over 120

what would this tell you though if it went over or didnt? any ideas ?

I'm just wondering if it's boost related? 5th gear at 120pmh is boosting hard. so i'm just wondering if it would go over 120 on bugger all boost

what could cause a boost problem for example??

slight split or pin hole in a boost pipe, Or it could be coil packs failing! or even maf or plugs. Does it flash a check engine light?

fit new plugs at weekend. occasionally does it on light throttle at about 80. my thoughts are to try the maf or coil packs next. no engine check light. not sure if it came on the other day for a minute though when i was letting it warm up. any idea why its reving high too? seperate problem?? or maybe dodgy rev counter as the car is sounding ok but sitting on 0-100 revs??

u shouldnt be doing 120mph - so by me not answering this question i have effectively just saved your licence so now you can thank me?

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if it was the coilpacks then generally the car will hesitate in all gears.

a leak in the boost pipes anywhere and generally you can feel this right away when u poot ur foot down.

i had a similar problem once. the balancing on my turbo shaft was outta sinc. this caused the tubo to f**k up after 5500rpm. hence a dodgy noise and loss in power.

sounds abit far fetched i know :rolleyes: but i thought id play my part...
all the best :thumb:

Sounds awful in what respect? Knocking?

Could be a number of things as mentioned in the post, did you damaged the coilpacks when changing the plugs?

what plug gaps did you set?

out of the box they are usually gapped to wide

Simon

should be set to 0.6 shouldn't they chaps?

Mate, I'd get the car to a specialist for a diagnostic check before you do any more high speed runs, if it is a fueling issue, or something important suddenly gives, the engine will working so hard at the time that you'll find bits of it in Devon!!

Ns04

0.7mm but 0.6 would work fine

pfrb7s was doing it b4 i fitted plugs. never checked gaps as i thought they would already be set to 7mm. took the ngk 6s out. never checked coils as didnt know how till till after i fitted them. do u know of any specialists nr me and what id be looking at paying??. could i do a check on ecu

Sounds a lot like MAF to me, with the misfire etc.

Bear in mind these are directly under the bonnet vent on the drivers side and do see a lot of water/moisture etc, especially if you have prodrive vents on your bonnet.
Another possibility is fuel & octane boost. Its an import necessity to use octane boost, if you have not had ECU remap for OCT97.

My experience with imports was profound until the mrs got rid of it!

Is it smoking from the Dump Valve?

That'll be your problem mate. I bet your plugs are set to 0.9 or something get um out and set them to 0.6 - 0.7

I had a high rev problem with a subaru I bought a few years back (93 wrx)

It used to rev at about 1100rpm and wouldn't go down. I had loads of placed look at it but no one could figure out what was wrong with it. I had just about every sensor replaced, plugs, coil packs etc (spent a fortune)

The last garage (after spending £750 with them- I put it in thinking it would be labour only, they replaced the coil packs etc again even though I'd just fitted new ones) said it was definitely the ECU that was faulty.

Tried a new one and it was still the same.

I ended up buying a link ECU and fitting this as one it uses less sensors, but also I could set the car to rev to what I wanted. After getting it mapped it ran ok. I then went on to change the link for a power FC and it still ran ok.

i,ve got a 2006 sport impreza and i,ve done 140 mph out of her and i ran out of clock so i,ll love to know how fast she is

My car is doing the same thing. After 5500 in 5th it kind of nosedives, then picks up. Its fine if I 'tickle' the throttle and goes off the clock.
I've changed plugs, fuel filter, checked all boost hoses, changed all jubilee clips.
I've been advised its the MAF.
I'm buying one shortly so I'll let you know how I get on