Hey all just popped shark and had a stage 1 map put on my car. It's great until I hit 3k plus in 5th and it surges pretty badly. Still pulls like a steam train just very on off. What could it be?

Few things come to mind mate: N75, CTS, dirty intake air temp sensor (can be cleaned with Carb cleaner), MAF, MAP, some kind of leak. Could try a scan but I suspect it's one of those things that won't show. Try a run with MAF unplugged

Iv removed the n75 and put resistors in. Pulled the maf off and it runs like ****. Just thought could it be the **** fuel iv got in it?

I would talk to Shark. They will sort it out for you.

Could well be, bog standard unleaded was it? You really need super at the very least, preferably v power or momentum. What do you usually run?

Other than that I'd be thinking cts, map or iat sensor. Map sensor is not a common failure, but cleaning iat sensor won't do any harm. If it were cts it may be worse more generally, try some proper fuel and clean iat and see what happens.

Would one of your resistors going awry cause this? Don't know if ecu expecting a signal may be doing something...just a thought.

I would talk to Shark. They will sort it out for you.

Or do that lol. I rang r tech for some advice once and the first thing they asked me was about fuel mind.

Got 3/4 of a tank left lol.

Got 3/4 of a tank left lol.

Let it tick over overnight

Why would you remove the N75? If you do that, surely it'll just run on actuator pressure only and be as fast as a wet blanket?

N249 and N112 is what I meant. What's the n75?

Is it the bit near my dv?

N75 should come off the TIP, on the next bit along from the DV.

To all intents and purposes it helps control the wastegate and the ecu constantly adjusts it on the fly - if it's dying or the map is a bit off then you will get surging. Unlikely it's failed though, would think it's a mapping issue.

Shark are known to be pretty good - call them, they'll sort it.

Regarding fuel, and regardless of any sweeping statements already made, the first thing to do is ask Shark what octane they mapped it to run on!

Should still run ok no matter what fuel it was mapped on!

Makes a bit of difference but wont make the car run like crap.

Took back to shark and was unsuccessful in sorting out the surging. I'm trying to sort another visit to see if it can be sorted. Fingers crossed it can be. Iv heard lots of good things about them but I'm loosing faith.

My idle has become more erratic too.

Could well be, bog standard unleaded was it? You really need super at the very least, preferably v power or momentum. What do you usually run?

Other than that I'd be thinking cts, map or iat sensor. Map sensor is not a common failure, but cleaning iat sensor won't do any harm. If it were cts it may be worse more generally, try some proper fuel and clean iat and see what happens.

Would one of your resistors going awry cause this? Don't know if ecu expecting a signal may be doing something...just a thought.

Where is the iat and map sensor located. Mayaswell clean them. Might help a little.

Your MAP is on the end tank of your smic, I'm not sure whether cleaning that one is advisable or not...They're not a common failure, may be better as a trial and error replacement but I'd probably have that one at the bottom of the list. Your IAT is after the throttle body, at the beginning of the intake manifold with a plug on it. One allen bolt holds it in, just undo and slide it out, it's not very big. Use carb or contact cleaner, I used both. You can GENTLY clean the element with a toothbrush but don't damage it whatever you do. Just soaking it should get the grime off.

Erratic idle is often a sign of airflow going wrong somewhere...

Have you replaced the coolant temp sensor lately?

Sorry to hear it's not sorted yet, hope it is soon

No iv not replaced the coolant temp sensor? Where abouts is that located? What would that have to do with airflow tho?

Do you have any fault codes as mine used to surge in 5th years ago and used to pop up a 17705 fault code,think mine was as above something to do with throttle body area as that was part of the description on the paperwork when it went in under warranty.

Do a search for that fault code as there were lots of people with that code and surging but no definite answer but may be worth a read.

I had issues on a tuned car, fine when running Shell V Power but when I put a couple of Tanks of Tescos finest in the car it ran erratically & I got pants MPG, back to shell & it was fine. Momentum uses more chemicals to raise the octane on a low quality base fuel so needs more fuel to detonate, ( cheaper to make ) gives good power on full chat but is wasteful at lower load, hence the lower mpg & erratic running on "some" tuned & performance cars.  If it was a plug & play map then it may not suit the fuel you use as others have hinted at but Im sure you will have discussed this with Shark. . If you switch fuel it takes a couple of tanks to see a difference, or it may be that disconnecting the cars battery for an hour may clear the cars memory but I'm only guessing on that as I know it clears some records BUT MAKE SURE you have the radio code if needed to reset the radio before you do it  

 

If the car was genuinely fine before the map & is now pants the only thing that's changed is the map so somewhere with that either the maps wrong ( Shark are usually good so I doubt that ) or the change in parameters has highlighted an issue with the car. Best to work with Shark as I know they have a good reputation & will want to see you sorted or if they cant find the issue put it back to std & wait for the issues to develop. All us Keyboard warriors do is often give scraps of info without knowing the full story & that can confuse

 

If it hasn't been on a rolling road that would be one way of hi lighting the issue as parameters can be checked easily under load, much safer than live mapping & data logging on the road . In my opinion always the best way to map a car as it can be logged stock before mapping to look for issues but it costs more and these days its price most look at.   I would agree on a new std car plug & play maps OK as everything should work but as a car gets older or bits are modified the base point changes.

 

Im guessing Sharks map will be for a non modded car or within parameters so taking bits off like the N75 & fiddling with it probably wont help but anything you do / have done make sure they know as they will have a better idea of the effects than most of us

 

 

Best of luck & Im sure Shark will solve it for you but be prepared to fork out if anything else is broken or tired.

Did they get it to surge on rolling road ?

Any faults come up ?

Smoke tested ?

No iv not replaced the coolant temp sensor? Where abouts is that located? What would that have to do with airflow tho?

If you've got a split somewhere so air is getting lost or there is unmetred air somewhere tick over can get wobbly.

The CTS is on the cold side of the engine, green thing sticking out the top of a large coolant pipe as it runs toward the intake pipe area. Can cause all kinds of running issues without throwing a code. Airflow is a separate thing but can manifest in similar issues. A smoke test would be a good idea to rule airflow problems out.

As missingmyvrs says have any fault codes popped up? That dreaded 17705 covers a range of things. Often leak related, funnily enough mine was down to a software issue following a remap...

Will the fault code pop up on a normal fault reader? Shark only said about my evap delete bringing a code up but that's been mapped out. I removed the charcoal canister. It's not been smoke tested and not been on a rolling road.

The fuel iv put through it now is BP ultimate but iv been told by shark stage 1 can run fine on normal fuel. Only problem I had before the map was the idle would drop every now and then but other than that it was fine.