still battling........studder, hesitation, fuel cut? help please

[Brett Haviland]

try another MAF,  I had 5 of them (2g mafs) sitting around for ages.  Finally got around to testing them and 3 out of the 5 were bad and did not read correct Hz, logging the Hz of the maf and watching for dropouts would be a good idea. (but requires a scan tool with data, or a ocilliscope.
also how much boost is it running?  where is the GM maf located when u have it hooked up (intercooler pipe or intake pipe)

[GlenMartin]

Running 14-16 psi with it spiking a bit to 18. Can I check the Hz with Evo scan? The Gm maf is just like the stock one on the intake side. However it is not recirculated like the stock maf.

[Brett Haviland]

what do u mean its not recirculated like the stock maf?  does this mean ur venting the bov, and have the GM maf in the stock location?  if so this will not work, and will cause rich on shifts....  shoudnt cause a hesitation unless the bov is leaking under boost.


id try another maf before getting to much further into this.

Yes, evoscan should be able to log/readout maf Hz

[GlenMartin]

what do u mean its not recirculated like the stock maf?  does this mean ur venting the bov, and have the GM maf in the stock location?  if so this will not work, and will cause rich on shifts....  shoudnt cause a hesitation unless the bov is leaking under boost.


id try another maf before getting to much further into this.

Yes, evoscan should be able to log/readout maf Hz

what i mean brett is that i have two intakes. one that is like the stock one, but it is aluminium, that i have the stock maf hooked up to. its after market but looks exactly like the stock one. looks exactly like this. http://www.ebay.com/itm/INJEN-IS1890P-SHORT-RAM-INTAKE-POLISHED-1995-1999-MITSUBISHI-ECLIPSE-2-0L-/140882059476?pt=Motors_Car_Truck_Parts_Accessories&fits=Model%3AEclipse%7CSubmodel%3AGSX&hash=item20cd39a0d4&vxp=mtr

with the one above, i have the bov recirculated.

the second one i have the gm maf hooked up to. as followed. turbo> intake pipe> gm maf> filter. i dont have a pic but you get the drift. with this one i do not have the bov recirculated. so with two intakes i can just swap them back and forth easily for testing and such. currently i am having problems with the first set up. i will borrow the gf's laptop and log it this weekend then.


i should also mention that awhile ago i suspected that the ecu was causing this and travis shipped me his spare ecu, which was a known working one, and there was no change.
i found this post on tuners so i will be trying this on the weekend as well. i will let you guys know how it goes.
http://www.dsmtuners.com/forums/newbie-forum/279488-maf-mas-test-check.html#post151385215

[GlenMartin]

well i did this test today, and according to this article and my manual both mafs i have are good. i changed plugs to a colder heat range, gapped them and did this test and no change. i swapped back to the gm maf, and the difference is so drastic its not even funny. throttle response, how quickly it builds boost and how it idles. it really is remarkable. i am totally at a loss. other than its hitting fuel cut. that is my only idea. guess my porting job was just that good that it flows that well. hahah or the stock maf is just that bad.

http://www.dsmtuners.com/forums/newbie-forum/279488-maf-mas-test-check.html#post151385215

[GlenMartin]

well i took the car out, and boy don't ever buy bosch plugs. the one they had listed for my car were not the correct heat range. like two ranges colder than stock. i asked at the lordco what heat range they were and on the box it didn't have them on there, nor did it have them on the plug, i had to use the goggle machine to figure out the plugs were to cold. after a test drive of course. it ran like absolute shit. took the plugs out and there was no evidence that they were even working. i really hope i can take them back hahaha. i finally said fuck it, and stopped trying to figure out why stock mafs will not work in my car. i hooked up the gm maf and been driving it almost all weekend. there has been ups and downs but it is driving. worked out a high idle issue, fixed a fuel leak, but i still can't figure out why i am lean at idle. like 14.7-15.5. anything i do it just does not help. i am hoping a fuel pressure regulator and 785cc injectors will fix this, and 26 pounds of boost. hahahah. fix it real good. going to give the car the mechanics at school and say free tin to who ever changes my fuel filter. i just don't have the patience for that shit.

[Brett Haviland]

14.7-15.5 is exactly where u want to be. I actually lean out further, more like 16.5-17.5 at idle and light cruise for increase gas mileage. You have to usually increase timing advances tho when u go leaner to keep the drivability the same.

[Jason Harwood]

I tuned mine for 14.7 @ idle + daily driving before boost.

I also got unicorn gas mileage at this.

Just make sure under full boost you're not lean, thats my only concern.

[Eddie ly]

I cruise at 14.7~15 on the highway and my EGT reads just under 800c. I wondered if it's save to go any leaner?