Fuel cut maybe

2003.5_MSP

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2003.5 MSP
Hey guys just wondering what fuel cut feels like... I've noticed the past two days when I go WOT it seems like it is choking or struggling it seems to get fuel... Is what I described fuel cut issues? If so what can be done to get rid of it, I don't have a split second controller yet... My mods are in my signature

Thanks
 
If you are in 1st or 2nd gear, with fuel cut, you will almost smash your face on the steering wheel....
 
Well it does it in any gear anytime... It's almost like it has bubbles in the fuel line (but it don't) making it jerk back in forth... It's also my first winter with them 3" tb exhaust, we will see if that could be the culprit
 
Does it usually happen between 3.5k-4k rpms? If so I'm having the same issue and I think the solution may be a new wastegate.
 
My car has been doing the same thing but I do have an ssafc. I'm pretty sure it's fuel cut. It will drive normal but as soon as I go more than half throttle or mash the gas the car shudders and cuts out. This is my first winter with the FMIC and catless exhaust and the first time i've had issues with fuel cut.
 
I was having the same problem not to long ago and after replacing my coil packs and ignition wires with the problem still occurring I ended up replacing the waste gate with a replacement from ATP turbo. After replacing the waste gate I don't experience the problem anymore.
 
Idk what range it happens at, but as soon as I begin to go past half or just mash to the floor it happens... This is also the first winter like I said with my exhaust... Ill try the coilpacks first and if that don't work I'll try the wastegate... So horns, you still getting it with an ssafc? Is it able to be tuned to avoid fuel cut?
 
I changed the tune on the SSAFC but it still is there. It runs fine cold and when warm it has a small hiccup at idle and it stumbles like crazy whenever you try to boost. I am leaning towards the MAF since it only occurs after the car is warmed up.
 
i think its the maf too, i had my turbo off the car last month and the wg was fine, everything seemed to operated just fine
 
It might make sense that mine could be also the MAF... Bc awhile ago I got a MAF code, so I cleaned it with some MAF cleaner... Could that be related, as it does it sometimes when cold... But mostly after warm-up?
 
You will need a full stand a lone, not a piggyback/AFC to eliminate the PCMs MAF / IAT cut. When its cold enough you are going to not boost like normal. That does not mean there is something wrong with your car. So replacing coilpacks/WGA is not necessary unless you have tested them and confirmed them to be bad. Try not to go WOT and rather go easy on the throttle when its freezing. MSP responds better that way versus mashing the pedal to the floor.
 
are you sure? bc before i began having this issue the car drove fine (flooring it and slowly depressing the pedal) i guess the easiest way to explain it is the car has perfect vacuum and boosts right at about 3k and it will hold 8 psi perfectly but the car falls on its face. Is it just going pig rich and making it hit that wall? and i guess the only reason im having a hard time comming to terms with this is the fact that many people on this forum just run a SSAFC and say they dont have the issue
 
Yes I am sure about the throttle. Spent plenty of windshield time back in 2003 and since making observations. Also certain about the temperature reading signal sent to the MAF and the resulting impact on boost. And for sure to elimante that you will need go stand alone and bypass the MAF. The DSMAFC(what they were called back in the day) will not do that.
 
I've had the same issue too. In my case my spark plugs were bad and I was having misfires but did not throw a code. The car will also sputter in the midrange on very cold days. Sometimes MSPs will overcompensate for cold are and drowned themselves in fuel. I've seen my wideband hit it's low limit of 10:0 on cold days when the car sputters.
 
You will need a full stand a lone, not a piggyback/AFC to eliminate the PCMs MAF / IAT cut. When its cold enough you are going to not boost like normal. That does not mean there is something wrong with your car. So replacing coilpacks/WGA is not necessary unless you have tested them and confirmed them to be bad. Try not to go WOT and rather go easy on the throttle when its freezing. MSP responds better that way versus mashing the pedal to the floor.

I dont exactly mash it or go WOT, its anytime when i start to build boost it does it...


I've had the same issue too. In my case my spark plugs were bad and I was having misfires but did not throw a code. The car will also sputter in the midrange on very cold days. Sometimes MSPs will overcompensate for cold are and drowned themselves in fuel. I've seen my wideband hit it's low limit of 10:0 on cold days when the car sputters.

I also replaced my spark plugs to what the manual suggests for the MSP... I also happened to get a P0090 code when i ran the scanner, its says Fuel Pressure Regulator System Circuit or something along those lines... could this also be cause what im experiencing? bc IIRC the solenoid could be mechanically functioning properly but not electrically
 
Did you gap your plugs for the MSP? Most parts stores only show that gap for NA Proteges.

Fuel pressure will definately cause these symptoms. I'll have to look up P0090; I haven't had that one before.
 
Check your vacuum lines going to the fuel pressure regulator (Mounted on the top of the fuel rail). If you have a vacuum leak at the regulator, you will not be getting the correct fuel pressure.
 
Did you gap your plugs for the MSP? Most parts stores only show that gap for NA Proteges.

Fuel pressure will definately cause these symptoms. I'll have to look up P0090; I haven't had that one before.

Ya I gapped them to the MSP specs off of ALLDATA...

Check your vacuum lines going to the fuel pressure regulator (Mounted on the top of the fuel rail). If you have a vacuum leak at the regulator, you will not be getting the correct fuel pressure.

Ill have to check for cracked lines running to it, but i believe ive already ruled out vac leak... ive got no issues with having vacuum as im reading -20 on my gauges... Also how do you perform a test for vac leaks, just wondering bc it never hurts to try again...
 
I've had that code and I replaced the pressure regulator control soelinoid to no avail. Don't waste the 80 bucks...
 
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