Bogging down in 1st from a dig...
08-23-2009, 04:29 AM
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Bogging down in 1st from a dig... Took the car out tonight. It still has open headers because the exhaust shop has re-scheduled me 2 times now, and got tired of waiting.
Before I did my cam swap I raced a 2000 Z28 with SLP Intake and SLP Loudmouth exhaust only. I beat him by 3 lengths and was pulling on him both bottom AND top end...
Tonight I ran a different 2000 Z28 with custom dual exhaust and SLP Intake...he beat ME by 3 lengths...
I launched from 3000rpms first and it bogged like crazy. tried it again from 4000 and it STILL bogged down. It has NO ***** in 1st gear, but once it gets moving in the upper part of first, it runs like a raped ape and fast as hell the rest of the way.
Included is a video of my launch to give you an idea. Again this is with open headers and I am running on Goodyear Eagle Street Radials 275/40/ZR17's.
What the hell is causing me to bog down so bad in 1st??? A buddy mentioned backpressure since I am running open headers.
http://img502.imageshack.us/img502/8003/sany0005.mp4
Before I did my cam swap I raced a 2000 Z28 with SLP Intake and SLP Loudmouth exhaust only. I beat him by 3 lengths and was pulling on him both bottom AND top end...
Tonight I ran a different 2000 Z28 with custom dual exhaust and SLP Intake...he beat ME by 3 lengths...
I launched from 3000rpms first and it bogged like crazy. tried it again from 4000 and it STILL bogged down. It has NO ***** in 1st gear, but once it gets moving in the upper part of first, it runs like a raped ape and fast as hell the rest of the way.
Included is a video of my launch to give you an idea. Again this is with open headers and I am running on Goodyear Eagle Street Radials 275/40/ZR17's.
What the hell is causing me to bog down so bad in 1st??? A buddy mentioned backpressure since I am running open headers.
http://img502.imageshack.us/img502/8003/sany0005.mp4
08-23-2009, 11:01 AM
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Wow, you are bogging really bad...
I'm running open headers as well for the moment, but haven't gone from a dig yet, I have noticed I lost a bit of low end torque.
My neighborhood ricer told me it was because of backpressure, so I just laughed that off.
But, I've heard that since your O2 sensors are getting much more air it causes your car to run rich and use more fuel than it needs, that sounds a little more plausible to me.
I'm running open headers as well for the moment, but haven't gone from a dig yet, I have noticed I lost a bit of low end torque.
My neighborhood ricer told me it was because of backpressure, so I just laughed that off.
But, I've heard that since your O2 sensors are getting much more air it causes your car to run rich and use more fuel than it needs, that sounds a little more plausible to me.
08-23-2009, 06:12 PM
#7
If your running open headers with o2's, your fueling is going to be off the charts. You should have the y pipe on atleast! On top of that, your running stock gears w/ a cam and heads, thats another problem. Do you have a full tune and I don't mean mail order?
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08-23-2009, 06:15 PM
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it was tuned by madtuner, and I am also throwing 2 codes. This was addressed before, but I'll bring it up again. I am throwing P0335 Crankshaft Position Sensor A Circuit Malfunction, and P0336 Crankshaft Position Sensor A Circuit Range/Performance. I replaced the Crankshaft Position Sensor and deleted the engine codes and they both came back within 30 minutes.
Timing should not be off. I KNOW I installed the cam perfectly and even took pictures to prove it lol. I also KNOW I got the distributor on right because I took the cap off, and held the rotor in place while I installed it. Everything went on smooth and it runs good.....until I go from a dig...
Timing should not be off. I KNOW I installed the cam perfectly and even took pictures to prove it lol. I also KNOW I got the distributor on right because I took the cap off, and held the rotor in place while I installed it. Everything went on smooth and it runs good.....until I go from a dig...
08-23-2009, 06:19 PM
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not a full tune yet. I got the mail order to get the car going...the full tune will be as soon as I get the exhaust back on, all engine codes resolved, and then I'll take it down to Ft. Collins or Denver to get a full Dyno tune. Have not had time yet to do a full tune.
The only reason the exhaust is not on is because someone welded EVERYTHING up so it was one piece from the heads to the tips. I had to cut the exhaust to get the headers off to get the heads off...I should have had it fixed by now with flanges that will bolt up, but the exhaust shop rescheduled me 2 times already. The car has only been running for just over a week.
AS SOON as the exhaust shop gets me in, I will have the entire system bolted back up. I am not going to race it again till that exhaust is back on.
The only reason the exhaust is not on is because someone welded EVERYTHING up so it was one piece from the heads to the tips. I had to cut the exhaust to get the headers off to get the heads off...I should have had it fixed by now with flanges that will bolt up, but the exhaust shop rescheduled me 2 times already. The car has only been running for just over a week.
AS SOON as the exhaust shop gets me in, I will have the entire system bolted back up. I am not going to race it again till that exhaust is back on.
08-23-2009, 06:34 PM
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I KNOW...thats the point of this dude lol. I got the mail order because it was BETTER THAN STOCK to get it on the road again. I dont plan on KEEPING it. Like I just said. Once I get it mechanically sound I will take it to a shop to get dyno tuned. I just gotta get it right first. I have only had it running for a few days.
The mail order is just a temporary fix. Driving it 100 miles to get tuned on a stock computer would be a BAD idea.
I dont think this is the tune though, it runs GREAT through the rest of my power band, just not in 1st from a dig...
I know it cant run good if that LS1 beat me because I put 3 lengths on an exact one BEFORE the swap...All you did was tell me what I already know. I need to know what else this is...If anyone actually thinks the tune is the only cause then cool, say that and I'll be more content getting the full tune done after I get my exhaust back on...I just want to make sure that is the ACTUAL cause, and not one of several.
The mail order is just a temporary fix. Driving it 100 miles to get tuned on a stock computer would be a BAD idea.
I dont think this is the tune though, it runs GREAT through the rest of my power band, just not in 1st from a dig...
I know it cant run good if that LS1 beat me because I put 3 lengths on an exact one BEFORE the swap...All you did was tell me what I already know. I need to know what else this is...If anyone actually thinks the tune is the only cause then cool, say that and I'll be more content getting the full tune done after I get my exhaust back on...I just want to make sure that is the ACTUAL cause, and not one of several.
08-23-2009, 07:10 PM
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I did, I am having the exhaust fixed ASAP to remedy that potential issue, and I am looking at 3.73's, or 4.10's. Starting to lean more towards 4.10's. I need to re-enforce the rear too, so I will be adding a girdle, chrome-moly tubular axle brace, and anything else I can come up with to provide some more support.
Any idea what is causing the 335 and 336 engine codes though? ss.slp.ls1 mentioned his opti went out shortly after a 336...any experience here?
Any idea what is causing the 335 and 336 engine codes though? ss.slp.ls1 mentioned his opti went out shortly after a 336...any experience here?
08-23-2009, 07:39 PM
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It is, but I cant tell if it is an exhaust leak or not...I definately have a leak, but I dont know if that is what is causing the pops and backfires or not.
08-23-2009, 08:05 PM
#17
imo I would get the exhaust put on and leaks fixed(obviously). Then scan it make sure the
o2's are switching properly. Also recheck all ignition related componets and fuel pressure. If that all checks out and it's still popping, pull the opti(check your opti harness also). Oh and 4.10's are your friend!
o2's are switching properly. Also recheck all ignition related componets and fuel pressure. If that all checks out and it's still popping, pull the opti(check your opti harness also). Oh and 4.10's are your friend!
Last edited by kinglt-1; 08-23-2009 at 08:13 PM.
08-23-2009, 08:20 PM
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I know fuel pressure is good. I have a fuel pressure gauge in my A-Pillar which runs off of an Electronic Fuel Pressure Sending Unit on my Schrader Valve. My FP is 52 when I turn the key on, 46 at idle, 47 to 48 when cruising at 40 in 3rd, and at WOT 52. It holds pressure as well.
O2's are brand new, but I will re-check them again after I get the exhaust fixed.
Any clue about those damned P0335 and P0336 codes??? I'm kinda stumped unless it actually IS the opti, but anyone know for SURE the causes of those codes if I JUST replaced the CPS???
O2's are brand new, but I will re-check them again after I get the exhaust fixed.
Any clue about those damned P0335 and P0336 codes??? I'm kinda stumped unless it actually IS the opti, but anyone know for SURE the causes of those codes if I JUST replaced the CPS???
08-23-2009, 09:22 PM
#19
It's your opti man! I just looked at the paper work from when I had mine replaced 6yrs ago. I remember goin and buyin a crank sensor and all that stuff now lol. Mine threw the same codes. I broke down and took it to the dealer cause I was stumped like you. Damn I just rembered that lol. Always save your reciept's lol!