DW650cc inj. possible issues-now fixed

neverendingmods · 01-17-2008, 04:05 AM

I think my injectors I had put in for protune are causing some light throttle hesitation. I had TGV's done at same time also. What I'm seeing is varying AFR's by .5 at idle and hesition under very light throttle exactly @ 2500rpm it starts and doesn't go away until 2900rpm in any gear. Say 4th gear,35mph light constant touch of throttle. If I give it anymore than feather touch of gas it is smooth as glass. Checked for vacuum leaks and none found. AFR's never varied like they are now before TGV and the installation of DW650 cc injectors. I came across another users post on here that said he too had similiar issues with modded injectors. The 650's are nismo injectors while the 740's are modded stockers. Anyone else have this wandering AFR and persistent light throttle stumbling? I can't datalog so I'm watching AFR's(wideband) along with readout of Maf off AP which is also varying up and down slightly. If I can somehow pinpoint the injectors, I'll gladly work on replacing them. It's just that it performs great other than already mentioned scenario. It hasn't learned its way through this problem(ecu).

speedindustry · 01-18-2008, 09:31 AM

The only way to quantify injector flow is by flow-testing them.

I have personally not had any problems with DW injectors.

I have had 1 case with modified (not by me) side feeds where one of the injectors was stuck shut.

maybe it's the tune? maybe a ****ty intake causing the maf to read poorly?

neverendingmods · 01-18-2008, 12:28 PM

I'm gonna clean the maf and seal it up on the outside and see if it helps. Reminds me I have to go pick up some maf cleaner. I'm using the factory ram air inlet along w/txs shorty and am gonna plug the ram air to see if the readings are geeting whacked out since majority of tuning was done on dyno with only a little time spent trying to figure out the slight hesitation.

***Turbineguy*** · 01-18-2008, 02:51 PM

I've been chasing a similar issue while doing my own tuning with ST. Mine is between 4 and 8psi when held constant. For me it's basically an issue with the tune and not the injectors. My DWs have been flawless and idle better than stock. Also if you have an APS cold air they take a fair bit of tuning to get the intake calibrations where they need to be. Otherwise you can get the symptoms you describe. I would look more closely at what's going on with the intake calibration.

neverendingmods · 02-26-2008, 11:04 AM

Just wanted to update on my injectors. Injectors work flawlessly when scaled properly. For some reason my ex tuner had scaled my injectors as if they were PE850's and not the DW650's I had him put in car for tune. I even gave the guy the flow sheet from deatchwerks.

Car has been reprotuned by John @ precision tuning. Proper scaling of injectors and a complete rewrite of my map has my car very happy. Now, I too am happy.
Deatchwerks injectors are trouble free if tuner has used them before. If tuner hasn't used them, I highly recommend you tell the tuner to contact deatchwerks and ask for there recommended scaling. Or, do it yourself prior to install/tune and give it to your tuner. This will save you hundreds of $'s in tunes. Trust me on this. Not many use 650cc injectors but are perfect for the vf39 and whatever non turbo upgrades you throw at it.

flatthump · 02-26-2008, 11:08 AM

Quote:

Originally Posted by neverendingmods

For some reason my ex tuner had scaled my injectors as if they were PE850's and not the DW650's

neverendingmods · 02-26-2008, 11:16 AM

^^ More like

To say the least.

**ray@turbotek** · 02-26-2008, 11:27 AM

damn that sucks your injectors werent scaled right the 1st time. glad to see your car is running like new again

inproper injector saling could be very dangerous

neverendingmods · 02-26-2008, 11:44 AM

^ Absolutely dangerous. Should have seen what my +1 colder Iridium plugs looked like when I had compression test done prior to tune. MAJOR detonation was happening. But all is well now.

John@Precision · 02-26-2008, 09:54 PM

Quote:

Originally Posted by neverendingmods

^ Absolutely dangerous. Should have seen what my +1 colder Iridium plugs looked like when I had compression test done prior to tune. MAJOR detonation was happening. But all is well now.

Your motor is weak bro, you should get rid of that thing.... as a matter of fact, I would be more than happy to take it off your hands for a small fee. How bout 150$

Nah, very nice numbers for the set up... and that EWG is just nasty LOuD!!

neverendingmods · 02-27-2008, 03:39 AM

Quote:

Originally Posted by John@Precision

Your motor is weak bro, you should get rid of that thing.... as a matter of fact, I would be more than happy to take it off your hands for a small fee. How bout 150$

Nah, very nice numbers for the set up... and that EWG is just nasty LOuD!!

LOL! Yeah, it's definately loud. Sucks when you can't even stand next to your own car while it's being tuned. Seriously, me and Carlos(other dude there) had to run outta there. I wanted to record a quick pull on my cell but couldn't take it.

And yet I'll never get rid of it. Ialways smile when it opens up. Especially now.

LSE · 02-27-2008, 02:56 PM

^^ well good thing you found the problem before it was too late man.

I am also considering the 650's since I'm "almost" done convincing myself I won't upgrade the turbo on this car. I need to do more research on the 740s and possible issues with the stocker 39 though.

good times.

neverendingmods · 02-29-2008, 04:05 AM

When it warms up just abit outside, I'm gonna see what my IDC's are 4th gear pull. Before they were reading oddly low

.Real low.

01-17-2008, 04:05 AM	#1
neverendingmods Silver Member Car: 06 STi Fav Mod: Buying a beater for DD Location: DE/PA border Posts: 940 Join Date: Nov 2006 Trader Rating: (3)	DW650cc inj. possible issues-now fixed I think my injectors I had put in for protune are causing some light throttle hesitation. I had TGV's done at same time also. What I'm seeing is varying AFR's by .5 at idle and hesition under very light throttle exactly @ 2500rpm it starts and doesn't go away until 2900rpm in any gear. Say 4th gear,35mph light constant touch of throttle. If I give it anymore than feather touch of gas it is smooth as glass. Checked for vacuum leaks and none found. AFR's never varied like they are now before TGV and the installation of DW650 cc injectors. I came across another users post on here that said he too had similiar issues with modded injectors. The 650's are nismo injectors while the 740's are modded stockers. Anyone else have this wandering AFR and persistent light throttle stumbling? I can't datalog so I'm watching AFR's(wideband) along with readout of Maf off AP which is also varying up and down slightly. If I can somehow pinpoint the injectors, I'll gladly work on replacing them. It's just that it performs great other than already mentioned scenario. It hasn't learned its way through this problem(ecu). This ad is not endorsed by this member. Please register or login to hide this ad. Last edited by neverendingmods : 02-26-2008 at 11:56 AM.

01-18-2008, 09:31 AM	#2
speedindustry Amateur STI Driver Fav Mod: tuning Location: Metro Detroit Posts: 43 Join Date: May 2007 Trader Rating: (0)	Re: DW650cc inj. possible issues The only way to quantify injector flow is by flow-testing them. I have personally not had any problems with DW injectors. I have had 1 case with modified (not by me) side feeds where one of the injectors was stuck shut. maybe it's the tune? maybe a ***ty intake causing the maf to read poorly? Last edited by speedindustry : 01-18-2008 at 09:35 AM.*

01-18-2008, 12:28 PM	#3
neverendingmods Silver Member Car: 06 STi Fav Mod: Buying a beater for DD Location: DE/PA border Posts: 940 Join Date: Nov 2006 Trader Rating: (3)	Re: DW650cc inj. possible issues I'm gonna clean the maf and seal it up on the outside and see if it helps. Reminds me I have to go pick up some maf cleaner. I'm using the factory ram air inlet along w/txs shorty and am gonna plug the ram air to see if the readings are geeting whacked out since majority of tuning was done on dyno with only a little time spent trying to figure out the slight hesitation.

01-18-2008, 02:51 PM	#4
*Turbineguy* Non-Reformed Meth Addict Car: '06 WRB Fav Mod: A laptop and tuning software. Location: Swampbilly Central Posts: 2,385 Join Date: Feb 2006 Trader Rating: (8)	Re: DW650cc inj. possible issues I've been chasing a similar issue while doing my own tuning with ST. Mine is between 4 and 8psi when held constant. For me it's basically an issue with the tune and not the injectors. My DWs have been flawless and idle better than stock. Also if you have an APS cold air they take a fair bit of tuning to get the intake calibrations where they need to be. Otherwise you can get the symptoms you describe. I would look more closely at what's going on with the intake calibration.

02-26-2008, 11:04 AM	#5
neverendingmods Silver Member Car: 06 STi Fav Mod: Buying a beater for DD Location: DE/PA border Posts: 940 Join Date: Nov 2006 Trader Rating: (3)	Re: DW650cc inj. possible issues Just wanted to update on my injectors. Injectors work flawlessly when scaled properly. For some reason my ex tuner had scaled my injectors as if they were PE850's and not the DW650's I had him put in car for tune. I even gave the guy the flow sheet from deatchwerks. Car has been reprotuned by John @ precision tuning. Proper scaling of injectors and a complete rewrite of my map has my car very happy. Now, I too am happy. Deatchwerks injectors are trouble free if tuner has used them before. If tuner hasn't used them, I highly recommend you tell the tuner to contact deatchwerks and ask for there recommended scaling. Or, do it yourself prior to install/tune and give it to your tuner. This will save you hundreds of $'s in tunes. Trust me on this. Not many use 650cc injectors but are perfect for the vf39 and whatever non turbo upgrades you throw at it.

02-26-2008, 11:16 AM	#7
neverendingmods Silver Member Car: 06 STi Fav Mod: Buying a beater for DD Location: DE/PA border Posts: 940 Join Date: Nov 2006 Trader Rating: (3)	Re: DW650cc inj. possible issues ^^ More like To say the least.

02-26-2008, 11:27 AM	#8
ray@turbotek Authorized Vendor Car: 06 STI 03 EVO Fav Mod: WIFE Location: Montco PA Posts: 395 Join Date: Mar 2007 Trader Rating: (1)	Re: DW650cc inj. possible issues damn that sucks your injectors werent scaled right the 1st time. glad to see your car is running like new again inproper injector saling could be very dangerous

02-26-2008, 11:44 AM	#9
neverendingmods Silver Member Car: 06 STi Fav Mod: Buying a beater for DD Location: DE/PA border Posts: 940 Join Date: Nov 2006 Trader Rating: (3)	Re: DW650cc inj. possible issues ^ Absolutely dangerous. Should have seen what my +1 colder Iridium plugs looked like when I had compression test done prior to tune. MAJOR detonation was happening. But all is well now.

02-27-2008, 02:56 PM	#12
LSE Professional STI Racer Car: 06 STI WRB Fav Mod: Defi Gauges Location: Bethlehem PA Posts: 849 Join Date: Dec 2004 Trader Rating: (0)	Re: DW650cc inj. possible issues-now fixed ^^ well good thing you found the problem before it was too late man. I am also considering the 650's since I'm "almost" done convincing myself I won't upgrade the turbo on this car. I need to do more research on the 740s and possible issues with the stocker 39 though. good times.

02-29-2008, 04:05 AM	#13
neverendingmods Silver Member Car: 06 STi Fav Mod: Buying a beater for DD Location: DE/PA border Posts: 940 Join Date: Nov 2006 Trader Rating: (3)	Re: DW650cc inj. possible issues-now fixed When it warms up just abit outside, I'm gonna see what my IDC's are 4th gear pull. Before they were reading oddly low.Real low. This ad is not endorsed by this member. Please register or login to hide this ad.