MrMeanGreen Posted August 6, 2005 Report Share Posted August 6, 2005 Long story short, the car at Norwalk today ran a 12.2 @ 112 (14psi) compared to my previous best at the same track three months ago of 10.95 @ 126 (12psi). The #7 cylinder is showing constant misfiring through Hptuners scanning, and the car has an audible miss. Status: Plug: Changed with a brand new one, gapped at .035 - no change Wire: Changed with another cylinder wire, then a wire from a friend's 5.3L Silverado - no change Coil pack: Swapped with #5 coil pack - no change Compression: 180 Harnesses: all plugged in PCM: Reset - no change Then I unplug the #7 injector harness. The car runs the same as it did with it the injector firing, still missing on scan and audibly. I think this is the problem. Can anyone confirm this? I'm also hitting 96% duty cycle on these Delphi 50#, so I have to change them anyways. Opinions? 12.2 @ 112 w/ 1.8x 60' (1000 RPM launch). Not bad for a V7 Quote Link to comment Share on other sites More sharing options...
rl Posted August 6, 2005 Report Share Posted August 6, 2005 Do a leakdown, but I have seen injectors stick both open and closed... Quote Link to comment Share on other sites More sharing options...
desperado Posted August 7, 2005 Report Share Posted August 7, 2005 Is the injector getting the pulse? I am not sure if you can look at it with a test light to see it the voltage pulse is getting there. I know that a digital multimeter would not be able to measure it unless you had one with a peak hold or a delta fuction, the pulse time is to short for most meters to react and register the actual voltage. If nothing else I have an o-scope that I can look at that with. Let me know. Quote Link to comment Share on other sites More sharing options...
Guest racinbird Posted August 7, 2005 Report Share Posted August 7, 2005 Ive got a noid light if you want to borrow it, plugs into the injector connector and flashes to show pulse. Sounds like a bad injector if it ran the same with it firing and unplugged. You could always just take a long thin screwdriver and place on the injector in question and to your ear. Listen to see if it sounds like it is clicking the same as a known good cylinder. Sort of back yard mechanic but works Quote Link to comment Share on other sites More sharing options...
MrMeanGreen Posted August 7, 2005 Author Report Share Posted August 7, 2005 The pulse is there, just the injector is dying (not actually completely dead, yet). I've heard from several people recently that the Delphis hate heat and it kills them. Go figure, the #7 is right above the primary tube from the header, back in the corner next to the firewall. They've been in there about a year, so it's time to upgrade anyways. I can't believe I've maxed out 50# already. Shit Quote Link to comment Share on other sites More sharing options...
Nate1647545505 Posted August 7, 2005 Report Share Posted August 7, 2005 The pulse is there, just the injector is dying (not actually completely dead, yet). I've heard from several people recently that the Delphis hate heat and it kills them. Go figure, the #7 is right above the primary tube from the header, back in the corner next to the firewall. They've been in there about a year, so it's time to upgrade anyways. I can't believe I've maxed out 50# already. Shit The 50 pounders suck, the 65lb motronics are alot easier to dial in. still, 50lbs x 8 injectors = alot of fuel Quote Link to comment Share on other sites More sharing options...
Nitrousbird Posted August 7, 2005 Report Share Posted August 7, 2005 Mototron offers a 60# High Impedance injector now, and I've heard they either off, or will offer soon, a 65#. Quote Link to comment Share on other sites More sharing options...
MrMeanGreen Posted August 7, 2005 Author Report Share Posted August 7, 2005 The 60s have been around for a bit, and now they offer the 65#. Brian Palcisko (gold Formula from ls1source.com) runs them in his car. He recommended them to me and will be making me a good deal on some new ones Quote Link to comment Share on other sites More sharing options...
Nate1647545505 Posted August 7, 2005 Report Share Posted August 7, 2005 Opps, I just looked at the package, they are Siemens. Yeah, these things are expensive (and I only have six!) Quote Link to comment Share on other sites More sharing options...
MrMeanGreen Posted August 7, 2005 Author Report Share Posted August 7, 2005 Siemens makes them, Mototron sells them under their brand name. Quote Link to comment Share on other sites More sharing options...
Brandon Posted August 7, 2005 Report Share Posted August 7, 2005 Hit it with a screw driver, I did it to the sentra and it worked!!!!!!!! I agree with rl, its sticking in some form or another, just get new one anyways if your running such a high cycle duty. Quote Link to comment Share on other sites More sharing options...
Nate1647545505 Posted August 7, 2005 Report Share Posted August 7, 2005 Siemens makes them, Mototron sells them under their brand name. interesting. Quote Link to comment Share on other sites More sharing options...
MrMeanGreen Posted August 7, 2005 Author Report Share Posted August 7, 2005 Hit it with a screw driver, I did it to the sentra and it worked!!!!!!!! I agree with rl, its sticking in some form or another, just get new one anyways if your running such a high cycle duty. No doubt about it. I've come to find out that since LS1s run such high fuel pressure (58-62psi stock, mine levels out about 70-72psi under full boost), the 50# are good for about 550rwhp on a boosted car, the 60# 650rwhp, and the 65# 800rwhp. Being the car makes 14psi and the addition of a few minor mods, I'm guessing it sits about 580-590rwhp right now. We'll find out as it will need dynoed again to tune it with the new setup. I plan on getting the 65s if it's cost effective. Nate, yeah. Marketing at it's best Quote Link to comment Share on other sites More sharing options...
Lustalbert Posted August 7, 2005 Report Share Posted August 7, 2005 Damn. The 307 in my booick only has 2 50 lb injectors on it. On the brighter side, at least it didnt lean out and kill a piston. Quote Link to comment Share on other sites More sharing options...
TurboRust Posted August 7, 2005 Report Share Posted August 7, 2005 anthony you have a pm Quote Link to comment Share on other sites More sharing options...
MrMeanGreen Posted August 7, 2005 Author Report Share Posted August 7, 2005 Andrew, I'll make ya a deal on seven more Derek, got it and replied. Quote Link to comment Share on other sites More sharing options...
SPLN SUX Posted August 7, 2005 Report Share Posted August 7, 2005 are you going to get rid of those 50'??? They might work for the Z24. Some of the LT1/LS1 injectors work in the head with minor modification to the harness and casting. If you plan to get rid of em, i might be willing to buy em if theyll fit. Quote Link to comment Share on other sites More sharing options...
Lustalbert Posted August 7, 2005 Report Share Posted August 7, 2005 Actualy, it is a difrent injector, but i would be intrested in the others for building my big block. Leme know Quote Link to comment Share on other sites More sharing options...
Rotarded1647545491 Posted August 7, 2005 Report Share Posted August 7, 2005 still, 50lbs x 8 injectors = alot of fuel 400lbs or fuel (50# x 8) is alot but... Most of us FD guys are running 480 to 520lbs in injectors (2 x 160#) + (2 x 80 or 95#). Quote Link to comment Share on other sites More sharing options...
Nate1647545505 Posted August 7, 2005 Report Share Posted August 7, 2005 400lbs or fuel (50# x 8) is alot but... Most of us FD guys are running 480 to 520lbs in injectors (2 x 160#) + (2 x 80 or 95#). good god, are they low Z? Jesus, how do those things idle??? I'll guess I have to look over balljoint's car, I don't gander into the Wankel land to often. Quote Link to comment Share on other sites More sharing options...
Brandon Posted August 8, 2005 Report Share Posted August 8, 2005 400lbs or fuel (50# x 8) is alot but... Most of us FD guys are running 480 to 520lbs in injectors (2 x 160#) + (2 x 80 or 95#). Ya well you guys are special with your 2 cycle weed whipper gas too Quote Link to comment Share on other sites More sharing options...
excell Posted August 8, 2005 Report Share Posted August 8, 2005 The Delphi 50's actually flow around 42#, pieces of shit. Siemens 60's are GREAT injectors, and I hear the 85/90 high imp's are but weeks away... Quote Link to comment Share on other sites More sharing options...
ZYUL8TR Posted August 8, 2005 Report Share Posted August 8, 2005 Swap the #5 and #7 injectors around. See if the problem moves to the #5 cylinder. Quote Link to comment Share on other sites More sharing options...
excell Posted August 8, 2005 Report Share Posted August 8, 2005 Swap the #5 and #7 injectors around. See if the problem moves to the #5 cylinder. We're going to do that. I believe the problem is heat related. #8 was a little spotty too, and since those injectors are in the back of the engine under the cowl with no direct air-flow I think they are getting hot and malfunctioning. Those Delphi's are very sensitive to, well, ANYTHING because they are garbage. The car did not sound like it was missing when I picked it up, but at the track in the heat it DEFINITELY was. I confirmed this by pulling the harness to the #7 injector and the pitch of the motor did not change. When I dropped it off last night, it sounded fine also. I was too tired to put the scanner on it and check, so I'll leave that up to Anthony. Quote Link to comment Share on other sites More sharing options...
MrMeanGreen Posted August 8, 2005 Author Report Share Posted August 8, 2005 I'll be running continuity tests in the harness in addition to swapping the injectors around. Bt no matter what, I'm upgrading. But I need to know if one is flake, and it seems difficult to find out without heating the piss outta them. I think another way to go would be to remove my cowl insulation to allow hot air to escape the rear of the engine compartment if it's indeed a heat-related issue. Things to do Quote Link to comment Share on other sites More sharing options...
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