LS1 RX7 not running right
06-24-2007, 07:47 PM
#1
LS1 RX7 not running right ok I just want to bounce this off some other people.
I got my car some what running I should say, with a base tune from my tunner but it will just not stay running when I touch the throttle it has no response at all and then it will die. I'm throwing one code witch is a P0102 Mass Air Flow (MAF) Circuit Low Input. Now I did do something a little different with my MAF in how it is mounted in a 4" pipe but I dont see this being the proublem unless I damaged it when I was moding it.
here is how I have it mounted
But even if the MAF is damaged I just dont see it as the reason the car is running so bad or not wanting to run. It will fire and idle but then if I touch the throttle it will die and it had to start agian. The tune sould be able to get me up and running but there is no way to drive it like this. and I pulled a plug today it you smell nothing but fuel so I belive it is way rich. Does anyone have any ideas as what to look for I'm thinking I need to take the ECM back to the tuner for him to have a 2nd try at it.
Mods on the motor are
Comp cam .589/.589 236/236 112LSA
1 7/8 headers
4" custom CIA
http://www.obd-codes.com/trouble_cod...-low-input.php
I got my car some what running I should say, with a base tune from my tunner but it will just not stay running when I touch the throttle it has no response at all and then it will die. I'm throwing one code witch is a P0102 Mass Air Flow (MAF) Circuit Low Input. Now I did do something a little different with my MAF in how it is mounted in a 4" pipe but I dont see this being the proublem unless I damaged it when I was moding it.
here is how I have it mounted
But even if the MAF is damaged I just dont see it as the reason the car is running so bad or not wanting to run. It will fire and idle but then if I touch the throttle it will die and it had to start agian. The tune sould be able to get me up and running but there is no way to drive it like this. and I pulled a plug today it you smell nothing but fuel so I belive it is way rich. Does anyone have any ideas as what to look for I'm thinking I need to take the ECM back to the tuner for him to have a 2nd try at it.
Mods on the motor are
Comp cam .589/.589 236/236 112LSA
1 7/8 headers
4" custom CIA
http://www.obd-codes.com/trouble_cod...-low-input.php
06-24-2007, 08:39 PM
#3
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Im not sure what size the stock MAF sits in but the stock MAF is designed to sense the amount of air in a stock sized port, so if you make it wider then it will read differently so your gona have to tune it a little different. did you try cleaning the MAF? try that if not, check for vacuum leaks too. Did you take the car to get tuned or just do a mail order tune or what?
06-24-2007, 10:20 PM
#4
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I'm pretty sure running the maf like that will throw the calibration way off, hell, adding a lid on an f-body is enough to screw with it a bit. I'm sure you know how the maf works, so its pretty obvious that completely changing the flow characteristics through it will mess it up.
When I first got my ls1 running it ran pretty lean, it was cutting out at part throttle and that is just with bolt ons and a stock maf. A wideband is really useful to help you figure out what exactly is going on, when I realized how lean my car was running, I turned off the MAF and added like 5-10% on the VE table and the car ran waayy better, just a bit rich....cleaned up the VE table and it runs great. I've since turn the maf back on, and recalibrated it, now she runs like a champ. I'd think you'll very likely need to recalibrate your maf, but you'll probably want to get you VEs in line first.
When I first got my ls1 running it ran pretty lean, it was cutting out at part throttle and that is just with bolt ons and a stock maf. A wideband is really useful to help you figure out what exactly is going on, when I realized how lean my car was running, I turned off the MAF and added like 5-10% on the VE table and the car ran waayy better, just a bit rich....cleaned up the VE table and it runs great. I've since turn the maf back on, and recalibrated it, now she runs like a champ. I'd think you'll very likely need to recalibrate your maf, but you'll probably want to get you VEs in line first.
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06-25-2007, 09:58 AM
#8
That meter definatly wont work right. Also at High volocity, i would say that it will break and get sucked into your engine at wot. There will be alot of force on the electronics and with no support of it on the bottom on your picture will create alot of leverage to make it break even easier.
A meter has to be set up EXACTLY for the enclosure that the electronics are in. You cant just change the houseing and expect it to Count the accurate amount of airflow.
It will not work.
A meter has to be set up EXACTLY for the enclosure that the electronics are in. You cant just change the houseing and expect it to Count the accurate amount of airflow.
It will not work.
06-26-2007, 09:24 AM
#10
MAF low input means that there is a problem with the reference voltage sent from the PCM (ECU) to the MAF. Check the voltage input wire w/ a voltage meter. The input voltage should be 5 volts. The PCM s sending a code because it's not 5 volts. You need to find out why. Either the MAF is bad, another or more than one other sensor on the same reference voltage circuit can also be causing the problem. There could be a wiring issues....etc..
06-26-2007, 03:38 PM
#12
Personally, I wouldn't use the MAF in that configuration. You can get them to throw codes on a stock LS1 just by turning the MAF sideways...
I don't think 100 PSI would harm your injectors while they are closed. If you are worried about it flip the injector fuel rail over (with the injectors and fue lines connected) and turn the key on to prime the pump. If you don't see anything oozing out you are all good.
If you have to squeeze the MAF in such a rotten spot, just remove it and go to a SD tune.
I don't think 100 PSI would harm your injectors while they are closed. If you are worried about it flip the injector fuel rail over (with the injectors and fue lines connected) and turn the key on to prime the pump. If you don't see anything oozing out you are all good.
If you have to squeeze the MAF in such a rotten spot, just remove it and go to a SD tune.
06-26-2007, 08:39 PM
#13
Do you got a wideband?? I know what is happening.
Do yourself a favor and just don't use the MAF. The way you have the MAF it is making your car too lean. Don't run it like that. Eliminate the codes from displaying a MIL, but don't disable them. Then, tune the car.
Do yourself a favor and just don't use the MAF. The way you have the MAF it is making your car too lean. Don't run it like that. Eliminate the codes from displaying a MIL, but don't disable them. Then, tune the car.
06-30-2007, 04:32 PM
#15
ok I got a stock MAF on it now and it does run better. But the car is still so rich that is is fouling plugs, I'm thinking that if I drop the fuel pressure some will that help to lean it out for the moment so I can run it to get it up to temp to test the fans and make sure the stat will open. I'm not looking for a permenent fix I just want something I can do right now with out tunning software to keep it running ok.
