Mafs, boost leak, or.....?

[Nissandriver714]

So I was boosting UNDER .8 bar and all of the sudden I hear some small poping sound, kinda like exhaust backfire. The car then proceeds to stutter and seems to have idling problems, but it the idle picked up and becomes normal again. I tried boosting again and it was weaker than before. At this moment, I'm guessing it's gotta be a boost leak somewhere, or maybe the mafs. Everything works fine now, except the idling problems and it doesn't seem to hold boost as well (butt dyno). I'm leaning towards the mafs being dirty or it's somehow acting up. This is a redtop btw. Any other possibilities? Can I use the 89 SOHC KA mafs to test it out cuz my fren has an 89 also. Thanks...
Also, whenever I start the car now, idle drops like crazy, almost turning off the engine. I gotta gas it to keep it from turning off.

[speeddreamz]

So I was boosting UNDER .8 bar and all of the sudden I hear some small poping sound, kinda like exhaust backfire. The car then proceeds to stutter and seems to have idling problems, but it the idle picked up and becomes normal again. I tried boosting again and it was weaker than before. At this moment, I'm guessing it's gotta be a boost leak somewhere, or maybe the mafs. Everything works fine now, except the idling problems and it doesn't seem to hold boost as well (butt dyno). I'm leaning towards the mafs being dirty or it's somehow acting up. This is a redtop btw. Any other possibilities? Can I use the 89 SOHC KA mafs to test it out cuz my fren has an 89 also. Thanks...
Also, whenever I start the car now, idle drops like crazy, almost turning off the engine. I gotta gas it to keep it from turning off.

Yes, your maf could be toast. If your idle is "rough" , open the hood, pull the maf plug, it'll sputter for a second, but then the idle should get better, if it doesn't then its not your maf thats the problem.

Try spraying carb cleaner around hoses that could possibly be leaking boost, if you have a hissing sound, spray it around there and see if the idle gets better.

Other thing, what about your spark plugs, new/old? sometimes thats the problem you can run a diff spark plug, it might not be gapped right.

and yes, you can use the sohc ka maf on the sr. Good luck!

[mrmephistopheles]

have you even attempting to check your piping? if there is an improper seal anywhere after the MAFS, your engine won't run right. It COULD be the MAF, but it's 90 times easier to check your piping first.