I have a strange problem in my car after being tuned. it feels like fuel cut but it is intermittant. I'm using a tec III stand alone and all the fuel cuts are disabled. It doesn't do it consistently but it is ALWAYS at full boost (10-15 PSI or so). Would this be spark blowout? I have an MSD fuel pump with 750 CC injectors so i really doubt it's a fuel pressure issue. What are the symptoms of spark blowout?
Kris Bloom
Street Challenge
http://www.streetchallenge.info
Http://www.streetsourcemag.com/projectz/ <--- The Cav
mmm...
Evolution of Cavyboy-->C22t--> C24na--->c24s/c
1995 Cavalier W/2k1 Engine
GM S/C 13.940@99.78pmh w/2.068 60ft
Here's just a random thought.
Ever think to check the fuel pressure regulator not being able to handle the extra oomph being thrown at it by the extra push the booster pump is giving the fuel system? Or the OEM fuel pump is conkin out? I used to have this funky weird cut that would happen when I'm gettin on the car in WOT and in top of third or top of 4th. Car would just cut. Changed the fuel pump, upgraded the wiring going to the fuel pump to make sure it gets all the voltage it could ever desire, and the fuel pressure regulator. Everything seems much safer now, for me.
-Trailblazer SS - not so custom 6.0L - custom intake - custom tune
- (1) 2.4L on an engine stand (1) blown trans (2) good quad trans (1) eco trans = party
Do you have a WB O2 sensor, and what is it doing when this power loss occours?
15.3 @ 89.97mph, 14's on the way?
Kris Bloom wrote:i keep hearing about these rapid fire #5's. I assume they are cold enouph for 15+ PSi of boost? I think a gap of .032 is good... you agree?
I have used these and liked them. I think they are 2 stages colder. We usually play with the gap between .032-.035. Get 2 sets of plugs so you can play and swap.
FU Tuning
i was thinking that the pump couldn't handle it aswell.
Anybody here do the fuel pump upgrade? do u know the part number for it?
Nate
Evolution of Cavyboy-->C22t--> C24na--->c24s/c
1995 Cavalier W/2k1 Engine
GM S/C 13.940@99.78pmh w/2.068 60ft
I know you said that you have all the fuel cuts turned off but do you have the overboost fuel cut disabled in the fuel enrichment menu? what are you using as your reference for rate of change fuel enrichment, MAP or TPS? What do your VE and spark tables look like at your upper MAP cells, are you calibrated from 1kPA - 208kPa? are you using the 2bar map sensor from electromotive? if so are you spiking over 2 bar and should be using the 3 bar MAP sensor? all of these are potential problems based on the TEC 3. Also, what firmware version do you have?
C24s/c wrote:i was thinking that the pump couldn't handle it aswell.
Anybody here do the fuel pump upgrade? do u know the part number for it?
Nate
From what he first explained sounds like it could be spark blow out. I had issues with stock pump dying, but the car would nose dive when this happened. I also had a fuel pressure gauge in the car so we knew what it was. When we had spark blow out it was like the car wanted to pull but was stuck.
FU Tuning
try 24 thou..you can go as long as 18 thou.. but that is a cheap bandaid... to a poor ignition. if it gets better you have spark blow out. 2.4 IDI
HP Tuners | Garrett T3/T04B | 2.5" Charge Pipes | 2.5" Downpipe | 650 Injectors | HO Manifold | Addco front/rear | Motor Mounts | HKS SSQV | Spec stage 3 | AEM UEGO Wideband | Team Green LSD | FMIC | 2.3 cams | 2.3 oil pump swap | 280WHP | Now ECOTECED
Dallas Blake wrote:I know you said that you have all the fuel cuts turned off but do you have the overboost fuel cut disabled in the fuel enrichment menu? what are you using as your reference for rate of change fuel enrichment, MAP or TPS? What do your VE and spark tables look like at your upper MAP cells, are you calibrated from 1kPA - 208kPa? are you using the 2bar map sensor from electromotive? if so are you spiking over 2 bar and should be using the 3 bar MAP sensor? all of these are potential problems based on the TEC 3. Also, what firmware version do you have?
Yes, i have the overboost fuel cut disabled. It uses a map for fuel enrichment using a 3 bar map sensor.
I have a theory i am testing. It's been a while since i have driven the car cause it has been in the shop for about a year, but i do remember fuel issues when the car had less than 1/4 of a tank. I've spent hours at the drag strip and thru tial and error i noticed a similar problem a few years back. I just forgot about it. When doing hard pulls with less than 1/4 of a tank of gas the fuel pump seemed to suck air. More than likely due to the movement of fuel in the tank during hard acceleration. After remembering that issue i noticed the tank was well below 1/4 of a tank. So i'm going to test to see if this was my problem.
btw, i pulled the plugs, they are correct. NGK TR6's gapped at .32
Kris Bloom
Street Challenge
http://www.streetchallenge.info
Http://www.streetsourcemag.com/projectz/ <--- The Cav
John Higgins wrote:Kris Bloom wrote:i keep hearing about these rapid fire #5's. I assume they are cold enouph for 15+ PSi of boost? I think a gap of .032 is good... you agree?
I have used these and liked them. I think they are 2 stages colder. We usually play with the gap between .032-.035. Get 2 sets of plugs so you can play and swap.
I thought i had spark blow and installed msd. no difference. new plugs gapped to 032 from .035, no difference. Swapped injectors...no difference. new fuel filter, no difference. GOing to swap in another pump when i get a chance. hoping that makes a difference.
nate
Evolution of Cavyboy-->C22t--> C24na--->c24s/c
1995 Cavalier W/2k1 Engine
GM S/C 13.940@99.78pmh w/2.068 60ft
Are you sure it's spark blowout and not a lean misfire?
-Chris-
-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
sounds like we might have the same issue. I checked fuel pressure yesturday it was fine, I grounded the battery to block, and block to strut tower, changed my lifters, and changed the crank position sensor... I still have no luck. I thought it might be my injectors so I went bigger, also redid the exhaust (had to be larger anyways) and when I hit 5300-5400 it is like I hit a brick wall. I get tonnes of KR, and when I disabled it I had some ping action going on.... this frick'n sucks, I am only running 9 psi
HP Tuners | Garrett T3/T04B | 2.5" Charge Pipes | 2.5" Downpipe | 650 Injectors | HO Manifold | Addco front/rear | Motor Mounts | HKS SSQV | Spec stage 3 | AEM UEGO Wideband | Team Green LSD | FMIC | 2.3 cams | 2.3 oil pump swap | 280WHP | Now ECOTECED
Like I said - lean misfire.
What was your A/F gauge reading when you were getting it?
-Chris-
-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
SweetnessGT wrote:Are you sure it's spark blowout and not a lean misfire?
-Chris-
Almost positive. No matter how rich i make it with hpt, when i hit 5psi of boost +.. under moderate to wot, the afs go lean and the car hesitates. positive its the pump. just waiting for my new one to arrive.
Nate
Evolution of Cavyboy-->C22t--> C24na--->c24s/c
1995 Cavalier W/2k1 Engine
GM S/C 13.940@99.78pmh w/2.068 60ft
There is quite a bit of false information going on here. If spark blow is occuring it really isnt as much a matter of gap as it is indexing of the plugs. If the plug is able to spark, a closer gapping is just just a bandaid because it only reduces the intesity of the spark, which in turn allows it to be blown out just as easy. What happens when you have an improperly indexed plug is that the air and fuel entering cylendar actually go straight at the open end of the plug, causing it to blow out. If you face the plug away from the intake valve it doesnt allow the incoming air/fuel a direct path to blow it out.
Pull out the plugs, mark the plug with a sharpie so that you can see which way the plug is facing when it is installed and tourqued down. If it is facing the intake valves, buy some cheap ass plug indexing washers that change the alignment of the plugs to face toward the exhaust valves.
Honestly I believe this is one of the most overlooked tuning aspects of a car, or any motor for that matter. Every snowmobile or car I buy, gets the plug index check right away. The optimal index is plug straight toward the intake ports for power, but if it is blowing out obviously you have a problem and need to go to the exhaust port with the plugs.
I am not even joking when I say that my lawnmower runs much better with the plugs toward the intake port. That is how important plug indexing is. But for some reason so many people overlook its critical importance.
Fix the link of post the numbers...
- 93 mph in the 1/8 mile
Member of J-Body Of Michigan.
well guys, problem isn't fixed. I think it might be a misfire caused by being to rich. It does it real bad when not fully warmed up. I think my warmup enrichments may be causing a over-rich AFR under boost. It hits a good 11.5 when warmed up, and reads really rich (goes below the AEM widebands range) when fairly cold. What air fuel typically causes rich misfires?
Kris Bloom
Street Challenge
http://www.streetchallenge.info
Http://www.streetsourcemag.com/projectz/ <--- The Cav
Kris Bloom wrote:well guys, problem isn't fixed. I think it might be a misfire caused by being to rich. It does it real bad when not fully warmed up. I think my warmup enrichments may be causing a over-rich AFR under boost. It hits a good 11.5 when warmed up, and reads really rich (goes below the AEM widebands range) when fairly cold. What air fuel typically causes rich misfires?
Don't go into boost when the car is still warming up.
Sunfires... eh (Tom) wrote:Kris Bloom wrote:well guys, problem isn't fixed. I think it might be a misfire caused by being to rich. It does it real bad when not fully warmed up. I think my warmup enrichments may be causing a over-rich AFR under boost. It hits a good 11.5 when warmed up, and reads really rich (goes below the AEM widebands range) when fairly cold. What air fuel typically causes rich misfires?
Don't go into boost when the car is still warming up.
Well, yea... that's the plan, but i'd like to know what air/fuel would "usually" cause misfire under boost.. That may not be an answerable question, but someone might have an idea
Kris Bloom
Street Challenge
http://www.streetchallenge.info
Http://www.streetsourcemag.com/projectz/ <--- The Cav
In regards to plug indexing. I have always done that. And getting hesitation regardless. Will know when i throw the new pump it.
Evolution of Cavyboy-->C22t--> C24na--->c24s/c
1995 Cavalier W/2k1 Engine
GM S/C 13.940@99.78pmh w/2.068 60ft
