Dshaff36 Posted May 19, 2012 Report Share Posted May 19, 2012 Okay, so I just installed a 3" gm maf and maft and when test driving it I noticed that when I press the clutch to decelerate the rpms drop rather quickly and it dies. I don't think it has anything to do with the maft settings, I have a feeling that I either messed something up when I took the charcoal canister out, or would leaving the hose that recirculates/vents the pcv system back into the intake just sitting open where it vents to the atmosphere be a possible cause? I feel like this has to be a simple issue that I overlooked but I just can't seem to track the problem down. Link to comment Share on other sites More sharing options...
Metric-man Posted May 19, 2012 Report Share Posted May 19, 2012 Decel is handeled by the ISC on a stock system. but you might have to adjust your translator as well.Have you tried using someone elses settings ?Is the 3" MAF a GM or aftermarket? Link to comment Share on other sites More sharing options...
Dshaff36 Posted May 19, 2012 Author Report Share Posted May 19, 2012 It's a GM unit and yes I am using someone else's settings right now. I have a stock fuel system with a big 16g, hard pipes, hks bov, and 3in exhaust, and my settings are:Aux: 0Base: 2Idle: 1Mid: 2WOT: C I feel like it wouldn't be an ISC issue though because everything worked perfectly fine until tonight when I installed the maft. Link to comment Share on other sites More sharing options...
Metric-man Posted May 19, 2012 Report Share Posted May 19, 2012 The Maf-t isn't specific to our cars and was actually made for DSM's first gen eclipse.you might need more fuel (larger injectors) in your case, but it would'nt hurt to adjust the ISC and TPS since your ECU is re- learning for the first 50 miles or so, you removed the negative battery cable for the install? Link to comment Share on other sites More sharing options...
StarquestRescue Posted May 19, 2012 Report Share Posted May 19, 2012 (edited) Removing and plugging the two small vac line to the canister should have little effect. If you also now have the hose from the oil separator that goes to the intake pipe open that will let un metered air into the intake when the engine is in vacuum. Changes like removing those hoses to the intake pipe can effect the vacuum in the engine which can also effect how a blow of valve works, causing it to no longer fully close at idle. If you do not have a wide band, your cruise and idle afr's may be off. Resetting the isc may also help after making changes in how the air flow is metered. Edited May 19, 2012 by StarquestRescue Link to comment Share on other sites More sharing options...
Dshaff36 Posted May 19, 2012 Author Report Share Posted May 19, 2012 Yes I did remove the negative cable. I'll plug the oil seperator line in and see if that does the trick then. Link to comment Share on other sites More sharing options...
89BananaQuest Posted May 19, 2012 Report Share Posted May 19, 2012 Did u plug the vacume line in the manifold where the pcv valve use to go? Also u may want to remove the pcv valve also if im not mistaken its set up to work with engine vacume and if u dont have it ran there it will not see vacume. Link to comment Share on other sites More sharing options...
ESIrType? Posted May 19, 2012 Report Share Posted May 19, 2012 Boston on the board here had a simular problem. When he would rev it and back off the car would die. The MAF was pre-turbo. What was happening was when you revved it and backed off there was compressor stall (even with a BOV). So the MAF was being back feed and didn't know what to do and the car would stall. He installed the MAF post turbo and this fixed the problem. Hope this is some help.. Shawn Link to comment Share on other sites More sharing options...
Dshaff36 Posted May 19, 2012 Author Report Share Posted May 19, 2012 (edited) Well I plugged the oil sperator back in and now my entire pcv system is in place the way it is stock but I'm still having the issue. I'll reset my isc but it just doesn't seem like that would be my problem. Could it be my maft wiring? I was a little confused when I spliced it to the stock harness, I used all of the stock wires except for the green/red stripe wire from the top row of my MAF plug, I used the green/red stripe wire from the bottom row instead since its the one that uses the IAT signal I believe. Edited May 19, 2012 by Dshaff36 Link to comment Share on other sites More sharing options...
Dshaff36 Posted May 19, 2012 Author Report Share Posted May 19, 2012 Boston on the board here had a simular problem. When he would rev it and back off the car would die. The MAF was pre-turbo. What was happening was when you revved it and backed off there was compressor stall (even with a BOV). So the MAF was being back feed and didn't know what to do and the car would stall. He installed the MAF post turbo and this fixed the problem. Hope this is some help.. Shawn Don't a lot of people install it pre-turbo though and have no issues? Maybe it's because the hks is a pull type bov? I am getting a pretty bad flutter with it so that makes sense... Link to comment Share on other sites More sharing options...
Skullzaflare Posted May 19, 2012 Report Share Posted May 19, 2012 Don't a lot of people install it pre-turbo though and have no issues? Maybe it's because the hks is a pull type bov? I am getting a pretty bad flutter with it so that makes sense...depends what size turbo you are running and how much boost15psi on a 14g and my maft would do the same thing, so i switched to blow through, and eventually upgraded to a 20g, and ran 25psi no problems Link to comment Share on other sites More sharing options...
Dshaff36 Posted May 19, 2012 Author Report Share Posted May 19, 2012 depends what size turbo you are running and how much boost15psi on a 14g and my maft would do the same thing, so i switched to blow through, and eventually upgraded to a 20g, and ran 25psi no problems I have my 16g boosting up to 15psi, but would that affect anything since I have the issue no matter what boost level I hit? Link to comment Share on other sites More sharing options...
Skullzaflare Posted May 19, 2012 Report Share Posted May 19, 2012 I have my 16g boosting up to 15psi, but would that affect anything since I have the issue no matter what boost level I hit?do you have a blow off? if so, when idling look inside it, if its locking open on vacuum it can cause it to screw up. but generally, my issue was with the bigger turbo the turbo was still pulling air when i let off, so it was dumping fuel when i didnt need any fuel Link to comment Share on other sites More sharing options...
Dshaff36 Posted May 19, 2012 Author Report Share Posted May 19, 2012 I looked and my blow off valve does not leak while idling. I still need to reset my ISC/TPS to see if that helps at all. I'd like to leave my MAF where it is before the turbo, but if none of these other things fix it, I guess I'll cut into my ovcp so I can put it there. Link to comment Share on other sites More sharing options...
Skullzaflare Posted May 19, 2012 Report Share Posted May 19, 2012 If you do, it will hit your heatshield on the hood, atleast i did Link to comment Share on other sites More sharing options...
DMNDSTAR87 Posted May 20, 2012 Report Share Posted May 20, 2012 Unhook bttry...unplug mas..put all settings to zero...rehook Btry....do isc/tps reset...keep aux/base at 0...I do not see any mention of a wideband...u r flying blind without knowing ur afr's....wideband is a must to dial in ur settings...the wires that u spliced can easily be identified to see if u wires something wrong---ur symptoms sound like tps/isc out of adjustment..just a crazy question is ur speedometer working?Gig out Link to comment Share on other sites More sharing options...
Dshaff36 Posted May 20, 2012 Author Report Share Posted May 20, 2012 Yea I did all of that and I'm still having the same issue. No I don't have a wideband but I'm going to get one soon. And yes my speedo works, but it's 9mph slow at 70mph. And I think I can clear the insulation fine if I put the sensor right before the tb. I guess I'll find out. Link to comment Share on other sites More sharing options...
Skullzaflare Posted May 21, 2012 Report Share Posted May 21, 2012 Unhook bttry...unplug mas..put all settings to zero...rehook Btry....do isc/tps reset...keep aux/base at 0...I do not see any mention of a wideband...u r flying blind without knowing ur afr's....wideband is a must to dial in ur settings...the wires that u spliced can easily be identified to see if u wires something wrong---ur symptoms sound like tps/isc out of adjustment..just a crazy question is ur speedometer working?Gig outspeedo is a cable, wouldnt be effected by anything, but agree with everything elseYea I did all of that and I'm still having the same issue. No I don't have a wideband but I'm going to get one soon. And yes my speedo works, but it's 9mph slow at 70mph. And I think I can clear the insulation fine if I put the sensor right before the tb. I guess I'll find out.shouldnt even be using a maft without a wideband, let alone running more than stock boost from a stock size turbolook at the poster above you's sig, best placement for the gm maf, it wont fit in front of the throttle body, atleast not without looking completely rigged and popping off, i havent seen a 2" to 3" adaptor either, seen 2.5" to 3", but your tb is 2" Link to comment Share on other sites More sharing options...
Dshaff36 Posted May 21, 2012 Author Report Share Posted May 21, 2012 shouldnt even be using a maft without a wideband, let alone running more than stock boost from a stock size turbolook at the poster above you's sig, best placement for the gm maf, it wont fit in front of the throttle body, atleast not without looking completely rigged and popping off, i havent seen a 2" to 3" adaptor either, seen 2.5" to 3", but your tb is 2" Yea I know I need a wideband but I have been focusing my car budget on other more important things since this is my daily driver and I need it to get me to work, so in the meantime I'm driving it very lightly. And I have an evo3 16g. And as for moving the MAF, I'm going to try a few other little things first to see if they can fix this problem first, but if not I'll move the sensor whenever I can find some free time after work. Link to comment Share on other sites More sharing options...
DMNDSTAR87 Posted May 21, 2012 Report Share Posted May 21, 2012 speedo is a cable, wouldnt be effected by anything, but agree with everything else shouldnt even be using a maft without a wideband, let alone running more than stock boost from a stock size turbolook at the poster above you's sig, best placement for the gm maf, it wont fit in front of the throttle body, atleast not without looking completely rigged and popping off, i havent seen a 2" to 3" adaptor either, seen 2.5" to 3", but your tb is 2" The vehicle speed sensor is in the dash cluster and without a working speedo the sensor reads that u r going 0 mph so the ECU gets a bogus signal and instead of holding the rpm's up for a split second beacuse it anticipates ur shifting not stopping the isc drops the idle so low for that second or so when brakeing it wants to and sometimes does stall---This happened to me and I replaced the speedo cable and pulse generator and problem was resolved.gig out Link to comment Share on other sites More sharing options...
Caliber308 Posted May 22, 2012 Report Share Posted May 22, 2012 (edited) Decel is handeled by the ISC on a stock system. He might want to start there. Stock system or MAF-Translator makes no difference. A ISC/TPS reset is in order. Bill Edited May 22, 2012 by Caliber308 Link to comment Share on other sites More sharing options...
Caliber308 Posted May 22, 2012 Report Share Posted May 22, 2012 (edited) Yea I know I need a wideband but I have been focusing my car budget on other more important things Nothing is more important than using a Wideband to set your MAF-Translator.(You put the cart before the horse).Trying to do it without one.....You will never get it to run correctly. P.S. Turn the base knob to zero. Bill Edited May 22, 2012 by Caliber308 Link to comment Share on other sites More sharing options...
Caliber308 Posted May 22, 2012 Report Share Posted May 22, 2012 (edited) Could it be my maft wiring? I was a little confused when I spliced it to the stock harness, I used all of the stock wires except for the green/red stripe wire from the top row of my MAF plug, I used the green/red stripe wire from the bottom row instead since its the one that uses the IAT signal I believe. Do a search on the proper way to wire the plug. The only wire that is not used is the Green/White wire.Both Green/Red wires are used. The MAF-Translator/ Stock plug is wired the same as if you were doing a Ist Gen Mas. Look in the Starquest FAQ forum under 1G Turbo Mas conversion. The Green/Red wire on the top row you didn't use is: Green/Red no.1. It connects to ECU PIN NO.5: Intake Air Temperature Sensor. Green/Red no.2 connects to ECU PIN NO.10: Sensor Power. (The MPS and TPS. wires are spliced into the Green/Red no.2 wire) on there way to ECU PIN NO.10. Bill Edited May 22, 2012 by Caliber308 Link to comment Share on other sites More sharing options...
Dshaff36 Posted May 27, 2012 Author Report Share Posted May 27, 2012 Do a search on the proper way to wire the plug. The only wire that is not used is the Green/White wire.Both Green/Red wires are used. The MAF-Translator/ Stock plug is wired the same as if you were doing a Ist Gen Mas. Look in the Starquest FAQ forum under 1G Turbo Mas conversion. The Green/Red wire on the top row you didn't use is: Green/Red no.1. It connects to ECU PIN NO.5: Intake Air Temperature Sensor. Green/Red no.2 connects to ECU PIN NO.10: Sensor Power. (The MPS and TPS. wires are spliced into the Green/Red no.2 wire) on there way to ECU PIN NO.10. Bill Well I'm wiring the Maft directly into my stock harness so the 1g conversion doesn't help, I was just confused on what to do since the translator has 5 wires while my harness has 6. But from what I've read I found out that that top green/red wire from the stock connector is left unconnected from the translator since the translator uses a fixed barometric pressure voltage. Also, I just got a wideband so I'm going to install that and see if my problem may be occuring if my translator settings are really far off, and if not, I'll look into moving the translator to the post-turbo side of my intake since there doesn't seem to be any other cause. Link to comment Share on other sites More sharing options...
Caliber308 Posted May 28, 2012 Report Share Posted May 28, 2012 (edited) Well I'm wiring the Maft directly into my stock harness so the 1g conversion doesn't help, So, I take it you didn't understand me? The wires from a DSM 1st Gen Turbo MAS plug are the same as the MAF-Translator wiring plug. If you are just wiring the two sets of wires together without a plug (Stock to Maf-t) It is the same as wiring a 1st Gen Turbo MAS to the stock wires.If you take the time to read that in the Starquest FAQ Forum you would understand. P.S. If you take the plug off of a 1st Gen Turbo MAS, cut your Stock MAS plug off, go to the section in the FAQ Forum that I suggested to match the wiring up, then the 1st Gen MAS plug will fit perfectly into the MAF-Translator plug and be wired correctly. Bill Edited May 28, 2012 by Caliber308 Link to comment Share on other sites More sharing options...
Recommended Posts