Vr4 issues and I'm stumped!!

[Guest]

So I thought I coud fix this issue but turns out I cannot, so I'm turning to the wiser for some help.


I borrowed the car to a friend for 2 weeks he did over 1500kms and gave it back with the following problems.
Misfire
popping sound from intake when accelerating
Surging
poor idle

Now the surging feels like a miss fire but as revs pickup it seems to come right but then the popping starts .
the popping sound seems to sound like its near the intake and you can feel it on the pedal and it comes in when boost picks up.

Iv replaced the boost solonoids and still does it.

Could or would it be any of the following?

MAF
Wastegate or Wastegate Actuators
Injectors
fuel Pump

Victim is a 99 facelift Galant tiptronic non tcl engine running a pfl gearbox and matching ecu

Please if there's anyone can help I'd appreciate it
there are also no faut logs either

 

[naughtika]

does it happen when the engine is hot? or also when cold?

if during hot, either there is a vacuum leak

or if it the issue also occur while cold, one of the vacuum hoses has probably come off..

 

[Guest]

That's the weird thing is if it was a vacuum leak it'd blow smoke but does not at all.correct?

 

[Guest]

Or idle at all afaik,what do you reckon

 

[Fred]

Wrong fuel - fouled plugs

 

[Guest]

Always run on 98 obtain and has new plugs in it

 

[NuffNuff]

I don't want to speak for Fred, but he might be getting at 91 Ron was used and fouled the plugs, by your mate. That's my assumption of what's happened. Fill it up on the cheap and hand it back

 

[Fred]

^^^ what damian said. May be worth asking your mate what fuel he ran for 1500 kms. If it was cheap crap, could have even blocked the filter also. If so new filter good fuel and ecu reset as it probably stuffed the timing up etc

 

[Fred]

BTW my old man did this to me, was missing and detonating hence the popping through the intake .

 

[Mel-D]

That's the weird thing is if it was a vacuum leak it'd blow smoke but does not at all.correct?

Mine didn't blow smoke and took 3 months to find it was a loose hose
I had a back plug that kept burning the electrodes off them and the exact same issue as your describing,we kept checking the vacuum and other hoses, changed the coil plugs which seemed to help for a while but the problem came back.It wasn't till one day Pete took the Maff off his car and put it onto mine to see if that helped but it didn't.And it wasn't till he put mine back on and the car wouldn't start at all he checked again still no luck,so took it back off and discovered that the exhaust hose underneath which was on before had come off, so replaced it and the car has not missed a beat since then. So we think that it was loose and when you accelerate it was sucking in too much air causing the car sorta backfire and the accelerator felt like it was kicking back underfoot and car would splutter and not seem to run on all cylinders.
Other members have had very similar symptoms like our and most of the time it's ended up being a hose of some sort (vacume or exhaust)not doing it's job properly.
So hopefully you find it's just something simple causing your problem.
Good luck

 

[Guest]

Hmm might look into this helpfull info from you guys, thank you,if you guys think of anything else please let me know please

 

[steveP]

I had a simlar issue on my previous car. It was the fuel pump starting to die. But it sounds more likely that the wrong fuel was used.

 

[TME_Steve]

How much boost is it running? What gap plugs? Can you see if its running lean at high load, ie do you have a wideband? When exactly does it do this (load and rpm)?

My guess is a combination of runing lean due to a blocked filter or stuffed pump and or plug gap/coilpacks/leads.

 

[Guest]

Thanx Steve new plugs recently,new packs,but might look at replacing,plugs,leadsacks,fuel filter, injectors and check hoses and go from there then ey?

 

[Jonson]

The backfiring through intake doesn't sound good. Detonation won't cause that....unless your inlet valves are open when the plug ignites, which then you have bigger problems!

It sounds like it jumped a tooth or 2 on the timing belt.....check belt timing - 20 min job.

 

[TME_Steve]

If you dont have a wideband check your fuel rail pressure.... john coild be on the money with the belt too but a miss on spark caused by heat (lean) could do that too....
Check all of the above

 

[Guest]

Top notch advice guys, I really greatly superly thank you for the advice and help,we are going to replace all vacuum hoses,leads and coils, new iridium plugs, fuel filter,check rail pressure,and check timing

 

[Guest]

​This is the email reply from my mate with the problem.im happy to say that he has now signed upto the site too.
welcome Andrew

Replaced all plugs with iridiums along with 3 new HT leads
All plugs looked ok, none appeared to be fouled.
Big improvement, now idling much smoother.When accelertating it's not mis-firing anywhere near as much.If you accelerate smoothly from start and dont "floor it" it doesnt "pop" at all and as the revs start to get up it still doesn't "pop". However if you are driving along and put your foot down hard thats when it missfires and pops, but it doesnt do it every time.
Also now noticed a misfire that may give us a clue to the problem, when starting off from idle as the revs pick up (approx between idle & about 1500 RPM), the engine misfires (without poping) then it revs up clean with no misfire. So its a low rev misfire when you first touch the accelerator. This could be coil pack or maybe a fuel mixture problem which takes me back to the AFM, what do think ?

 

[Guest]

Grrrr I'm not liking iPad tonight, POS!

 

[Rebound]

Sorry to sound dumb but are you talking about the (Maff) Mass Air Flow sensor ?