1990 breaking up for a long time

[doesitonall4rs]

Hey guys, this is for my GF's 1990 talon tsi, she has had the car for about 5 years now. For the longest time the car has had a really strange breaking up problem after 5000rpms.

This is her mod list
60-1, 44mm wastegate
2G maf (no honeycombs at all)
FMIC
Clutch
Full exhaust
1990 Eprom ECU with a chip for the injectors, and all that good stuff
880CC injectors
NGK Copper plugs
Magnacore wires
190LPH walbro
SAFC

Things I have tried over the years
Replaced the Coil with another 1990 coil
Pressure tested time and time again with no boost leaks discovered
Changed the ecu and got a chip thinking that maybe it was some sort of fuel cut thing, but no still the same bullshit.
logged and logged again car doesn't knock (so I'm thinking her fuel pump should be enough and its not some kind of breakup that is being caused due to knock)

My current guess is it might be the MAF sensor because it's missing all the honeycombs. But its strange because on my 1991 I have a 2G maf and i removed all the honey combs and the car has ran perfectly for years. Ive ran around 31PSI on that car with no problems. But on the same token my one friend removed all the honey combs on her 91 with a 2G maf and that car ran like complete shit. I'm not saying this to be cocky or anything but I am def not a noob when it comes to DSMs I have been around these things for years but my GF's car has me completely stumped.

Just trying to see what other ideas you guys might think I should try because her car has an awsome set up now and she can't even utilize it .

Thanks for anyhelp!

 

[ramsack]

I would get rid of the safc and just get a dsmlink to tune it. They have a lite version now that is $345. Also try more of a robust fuel pump. Check plug gap too. Do you have any way to control fuel pressure, and big enough of a supply line? You're always supposed to build systems for way beyond the power you want to make so if there is an error (overboost or something of the like) you won't fall too short on fuel or something else.

 

[FLASH1970]

From what I have read, an SAFC is only good up to about 680cc injectors. I would get a wideband on it and check the A/F ratio.

 

[DSMified92]

i would check fuel pressure and make sure the pump is not weak or if you would like just put a 255 in it. check the plug gap and maybe even the tps. i would say the maf is good but try swappin yours on to hers and running it down the road. what eactly is it doin when it hits 5k does it feel like a wall or just like its falling on its face or backfireing.

 

[doesitonall4rs]

i would check fuel pressure and make sure the pump is not weak or if you would like just put a 255 in it. check the plug gap and maybe even the tps. i would say the maf is good but try swappin yours on to hers and running it down the road. what eactly is it doin when it hits 5k does it feel like a wall or just like its falling on its face or backfireing.

It definitely doesn't hit fuel cut, but I it just feels like it falls flat on its face and backfires.

I don't think the SAFC is the problem, Although each car is different I was controlling 780s on my car for a long time with just an SAFC and a stock non eprom ECU, My timing must have been through the roof tho, but I think it helped on the methanol .

And the chip she has on her car is flashed for 880s so the SAFC is practically zeroed out just compensating a little bit for partial throttle and adding a tiny bit of fuel uptop.

I would get rid of the safc and just get a dsmlink to tune it. They have a lite version now that is $345. Also try more of a robust fuel pump. Check plug gap too. Do you have any way to control fuel pressure, and big enough of a supply line? You're always supposed to build systems for way beyond the power you want to make so if there is an error (overboost or something of the like) you won't fall too short on fuel or something else.

I was thinking about getting her link but I really think the problem is something else. Correct me if I'm wrong but isn't the 190LPH good for like 450ish to the wheels?

Her plugs are gapped at 28.

Another thing someone brought up on another forum is that it might need a fuel filter, I also thought about rewiring her fuel pump as well. But if any of the things were the problem wouldn't the car be getting crazy amount of knock?