Need help asap!!!
3/31/12, 10:25 AM
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Need help asap!!!
Ok new motor is in my car idles perfect and revs great , as soon has you drive it , it feels like the mass air sensor isnt letting air in ?
For an example feels like the cats are clogged (but I don't have cats) so I think my mass air is brand or not calibrated right (my mass air sensor is brand new also) any info will be great
Here's a quick video of my car idling
For an example feels like the cats are clogged (but I don't have cats) so I think my mass air is brand or not calibrated right (my mass air sensor is brand new also) any info will be great
Here's a quick video of my car idling
3/31/12, 10:50 AM
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Could also be fuel starved once she is under a load. This why ( but also could be unrelated to your problem) when I do an H/C/I and supporting mods I bring it in for a tune. May also be a spark problem. Sounds like the motor is falling on its face under load so look at fuel/spark. I'm not the type to trust calibrated mafs I'm more of the tune type. did you upgrade the fuel system?
3/31/12, 10:57 AM
#3
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Beat me to it man. +1 on fuel pressure. Will it let you rev it slowly if you ease on the throttle? Will it stay running if you unplug the MAF? MAF shouldn't cause this though. I have see a TPS or two do this also. Fuel pressure gauge test first.
3/31/12, 01:20 PM
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Originally Posted by AlsCobra
Beat me to it man. +1 on fuel pressure. Will it let you rev it slowly if you ease on the throttle? Will it stay running if you unplug the MAF? MAF shouldn't cause this though. I have see a TPS or two do this also. Fuel pressure gauge test first.
3/31/12, 01:21 PM
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Originally Posted by skunk21
Could also be fuel starved once she is under a load. This why ( but also could be unrelated to your problem) when I do an H/C/I and supporting mods I bring it in for a tune. May also be a spark problem. Sounds like the motor is falling on its face under load so look at fuel/spark. I'm not the type to trust calibrated mafs I'm more of the tune type. did you upgrade the fuel system?
3/31/12, 01:34 PM
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Originally Posted by skunk21
Could also be fuel starved once she is under a load. This why ( but also could be unrelated to your problem) when I do an H/C/I and supporting mods I bring it in for a tune. May also be a spark problem. Sounds like the motor is falling on its face under load so look at fuel/spark. I'm not the type to trust calibrated mafs I'm more of the tune type. did you upgrade the fuel system?
3/31/12, 01:43 PM
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Originally Posted by AlsCobra
Is it an auto or manual? It only does it under a load?
Yes only does it under load!
3/31/12, 01:49 PM
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revving the motor doesn't mean much if it it is under load then it still can be a fuel problem ie pressure regulator or weak spark. If you did the fuel system over and changed out the 19lb injectors I'm thinking to 24s atleast you should be getting a tune now for all your mods. also was it always an auto car?
also want to ad, new doesn't mean much ( although it should) I have seen brand new msd boxes bad out of the box and dizzies also.
also want to ad, new doesn't mean much ( although it should) I have seen brand new msd boxes bad out of the box and dizzies also.
Last edited by skunk21; 3/31/12 at 01:53 PM.
3/31/12, 01:55 PM
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Originally Posted by skunk21
revving the motor doesn't mean much if it it is under load then it still can be a fuel problem ie pressure regulator or weak spark. If you did the fuel system over and changed out the 19lb injectors I'm thinking to 24s atleast you should be getting a tune now for all your mods. also was it always an auto car?
3/31/12, 02:01 PM
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Now last year My car was bone stock, I put the 24lb injectors and 75mm mass air on and the car did the same exact thing it's doing now , I went back to my 19lbs and stock mass air and ran perfect so I just thought it was to much for the car and now with heads cam intake all supporting mods and 24lb injectors and mass air and it's doing the same thing
3/31/12, 02:05 PM
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Yes always a auto, I changed from 19 to 24lb injectors with a matching 75mm mass air sensor for 24lb injectors , I just but the SCT eliminator chip in from American muscle .... I'm also gonna give them a call or stop in there on Monday and see if maybe the didnt type the correct tunes on the chip for me or I just need a real dyno tune
I'm sorry and I don't want to start a war, but why do people go through all the trouble of building a motor and doing the supporting mods and not think it needs a proper tune and worse use a mail order tune. Please don't take me the wrong way it is just a huge peave of mine. When changing out the injectors, maf, etc and doing a head and cam swap do yourself a favor and get it tuned at a shop. Don't chip your motor, and I'm going to say chances are real high this is why it is running like crap.
3/31/12, 02:12 PM
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Might be on to something there. Built a couple foxes in my day and never needed to chip one. Just matching MAF to injectors and fuel pressure along with timing will do the trick. It's more of tricking the control system instead of tuning it.
3/31/12, 02:15 PM
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Originally Posted by skunk21
I'm sorry and I don't want to start a war, but why do people go through all the trouble of building a motor and doing the supporting mods and not think it needs a proper tune and worse use a mail order tune. Please don't take me the wrong way it is just a huge peave of mine. When changing out the injectors, maf, etc and doing a head and cam swap do yourself a favor and get it tuned at a shop. Don't chip your motor, and I'm going to say chances are real high this is why it is running like crap.I'm trying to see if I can fix the prob myself before I bring it for tune ( I looked at it had $250 for chip and mail tune and if it doesn't work I still have the chip they can re-write a custom tune with it on dyno)
2nd street speed in Pa, told me if I bought the chip they'll dyno tune for $350-$400
3/31/12, 02:16 PM
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no chipping is worthless but tuning is more worth while. matching the maf to the injector is only part of it, when taking the time do a nice H/C/I do the tune. The thing isn't dailed in right.
4/2/12, 08:10 AM
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Originally Posted by AlsCobra
Beat me to it man. +1 on fuel pressure. Will it let you rev it slowly if you ease on the throttle? Will it stay running if you unplug the MAF? MAF shouldn't cause this though. I have see a TPS or two do this also. Fuel pressure gauge test first.
4/2/12, 05:30 PM
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It should stay running or if dies it should start up. If anything the car should go into limp mode and throw a CEL. The fact that it dies leads me to Als other point the TPS since the MAf, ACT and ECT all work together in short terms. you could have a faulty TPS but the MAF could also be suspect.