I recently removed my intake, drilled it for direct port nitrous and re-installed it. I used new gaskets, attached all vacuum lines and torqued it down properly. At first it ran rough and would not idle so I did the idle re-learn procedure and now here is the problem. The car ran alright at first but after some brief driving it started to run rough again, coincidentally at the same time the temperature got to about 170 degrees. For example I am driving let off the gas to turn into the driveway and it dies. It acts like it can not find idle. After driving it I started it sitting in the driveway. It started and idled real rough. When I tap the gas it revs up then can�t find idle and wants to die. I scanned it and getting 2 codes: P0106 MAP sensor and P0101 MAF sensor. I am going to try replacing my plugs. Does anyone know what the KPA value should be from the MAP sensor? If anyone has any ideas please let me know. I have tried everything I know how. Replacing the MAP sensor is a last resort, that involves removing the intake again. And I don�t know why it should be bad, it worked fine before. Could tapping the intake and running lines to the distribution block change the internal characteristics of the intake enough to cause this problem?
Thanks for the help.
Chris

 

I'd bet that you are getting unmetered air from somewhere. Double check for vacuume leaks or a whistling/sucking noise.

 

Check were you taped the intake for the nozzle. I've heard that these can leak on a compostite intake.

 

Those nozzles are more than likely loctited in.So that should not be your vacume leak.Check to see if you intake did not seal down good.
Dave

 

Dave, I tried calling you earlier today, no answer. I think the nozzles are OK. I do think it is a vac leak, but have been unable to locate it yet. I guess I'll keep searching.

 

Sorry our phones are still messed up.They should be back up monday.It sounds like the intake did not seat right.
Good luck.Im sorry we are still a mess from the move.Let me know if I can do anything to help.
Dave

 

Can you still do the carb & choke cleaner trick with the efi cars? That's how we used to nail down an intake leak on the carbed cars, just spray it around the mating surface and the holes you drilled until you get a stutter from the motor.

 

Car update:
Checked all connections bt sparying carb cleaner over every connection and line, there is not a leak. Reset the codes and did an idle relearn. The car idles OK. I let it warm up to 170 then went for a drive. Car ran OK for about 10 minutes. It then started to miss and then died. I scanned the MAP and MAF sensor and saw no noticeable change to warrant the miss. Now the car idles rough like before, however I did not get any codes this time. I bet if I did a relearn that it would clear up again for a short time. Something is causing the miss after a brief drive. If anyone has any ideas please let me know. Otherwise it is time for the shop. Is there anyway the direct port nozzles could alter the flow inside the intake?
Thanks

 

This might sound stupid, but it wasn't made clear. You did install the solenoids and everything else for the nitrous system, or just the intake manifold that you plumbed for DP and maybe you are installing nitrous later..?

 

If I remember correctly, I'm seeing around 45-50 kpa at idle.... although thats with a cam, so I'm not sure about a stocker. May be a stupid question, but are you sure you hooked everything up in the back of the intake? I dont see the nozzles altering the flow enough to notice any difference in idle. Like Poik said... Is the whole system installed or just the nozzles. If its just the nozzles, are they capped?

 

Sorry but it sounds like a vacuum leak to me.

 

i say remove the intake and re-install it, an hours max worth of work is worth it. I know b/c i had exact same symptoms, i checked all lines 15 times. I finally pulled the intake and the edge of one of the wires running to the 2 knock sensors was pinched between the head and intake, thus causing ALL the problems. Pull and reinstall.

 

Thanks for the tips guys. The entire system is installed, except wiring. So the closed solenoids seal the system from external air. Which I will check to make sure the solenoids are fully seated. I am seeing about 80kpa at idle and cruising but it is constant. I was hoping spraying carb cleaner around the intake would find the leak, but no luck. I am going to pull the intake again and check everything out again. Has anyone installed the intake Oring gasket with grease or sikicone to promote better sealing?

 

Hate to sound redundant, but this sounds like the best plan of action. I have the same problem when I installed my Holley Intake. I went back and checked and had forgot to tighten the back 2 drivers side bolts down to the correct torque. Stupid on my part, I was in such a hurry to get it running (Heads, Cam, Intake install) that I got careless.

Pull it off, clean everything up, and reinstall it, carefully! Take your time, it'll be worth it!

Best of luck!
Taco

 

Update: Pulled the intake and checked all hoses again. No signs of leaks. Replaced the MAP sensor. Re-installed and now the car seems to run good again. Idles well and I have drove it about 20 miles without any codes or trouble. Also when scanning it yesterday the MAP consistently read 80-90 kPA, while the new one reads about 30 kpa, which I believe to be more accurate. Anyway after all that searching for leaks it turned out to be a $40 sensor. Thanks for all the help.

 

Glad to see your back on track..