boosting problems?!?!?!

[ford_o]

yes hello i drive a 89 240sx with a stock red top swap with front mount. i drive my car daily just fine but when i get on it and build boost it seems like it misses or bogs down! the car drives fine down the road but when i hit boost i have this problem.. open to any ideas to this problem thanks, ford_o please help!!!

[SidewayZ-s14]

yes hello i drive a 89 240sx with a stock red top swap with front mount. i drive my car daily just fine but when i get on it and build boost it seems like it misses or bogs down! the car drives fine down the road but when i hit boost i have this problem.. open to any ideas to this problem thanks, ford_o please help!!!

I'm having the same problem.

Well, when i 1st swapped in my SR i was having a HUGE problem like this. Found out it was my stock fuel pump not cutting it. Upgraded to the Walbro fuel pump and it solved my problem. Now the problem I'm having now sounds exactly like yours. It boosts and all, but when i REALLY get on it, seems like it's not getting enough fuel.

[ford_o]

yes thats the same for me! it runs fine through all my RPM's but when i hit full boost its like a brick wall!!!!!

[SidewayZ-s14]

Mines not that bad. Mine pretty much sputters and doesn't want to go anymore. I think it's fuel related.

[Monooxide]

There is a guy in Engine Tech who I replied to this identical problem last night, you should probably search.

However, the answer to your problem is most likely plugs. I had this same exact problem. Drove fine and then when it built roughly 8 PSI it would just hit a brick wall. Change your plugs to some Heat Range 7 and make sure theyre gapped to .028-.030.

[mr.jdm]

pressure check your system for boost leaks. its easy.

[Monooxide]

Lol, I forgot about that one. Ha, easiest one too. Also be sure to make sure you don't have a post MAFS leak on the intake.

[mr.jdm]

yea same thing happend to my eclipse. i thought my motor had blown. i gave it full throttle and as soon as my tires started to spin my head almost hit the steering wheel. scared the crap outa me. thought my motor was toast. turned out to be a loose coupler.

[deukalionS14]

I think it's the plugs...could be a leak but if it was wouldn't it have trouble building boost?

If its actually builds boost but has trouble when boost is built or while trying to accelerate i would put my money on the plugs. My fiance's car had the same problem for a while until we changed the plugs.

[SidewayZ-s14]

How often does one need to change plugs? I've had my SR for about a year now. Changed the plugs the 1st day i got the SR. Am i overdue? I didn't think you need to change plugs THAT often.

[5150Fab]

yes way over due....i change mine with every other oil change. easy and somewhat cheap.

my brother was having the same problem. when under a load it would misfire like crazy. did his plugs, its like a new car again.

[SidewayZ-s14]

yes way over due....i change mine with every other oil change. easy and somewhat cheap.

my brother was having the same problem. when under a load it would misfire like crazy. did his plugs, its like a new car again.

I'll give this a shot. Doesn't hurt to try!

[240cracker]

boost leak

happened to me

it could be as simple as a cuppling on your front mount is ripped or has a tiny hole.

[91drftr]

you guys should really try changing out the sparkplugs, it will most likely solve ur problem, i also had aproblem like this on one of my friends s13 where i couldnt boost right at 7 psi it would spudder and backfire a bit before it actually took off then we tried boosting 10 psi and it wouldn go passed 9 right at 9psi it would spudder and backfire like i had a bee- r rev limiter so i switched the plugs and the problems went away i was able to boost up to 15 psi with no problem. so tried it out just make sure u dont have any boost leaks cus a boost leak will give close to the same problems depending on how much ur actually leaking.:2f2f:

[SidewayZ-s14]

you guys should really try changing out the sparkplugs, it will most likely solve ur problem, i also had aproblem like this on one of my friends s13 where i couldnt boost right at 7 psi it would spudder and backfire a bit before it actually took off then we tried boosting 10 psi and it wouldn go passed 9 right at 9psi it would spudder and backfire like i had a bee- r rev limiter so i switched the plugs and the problems went away i was able to boost up to 15 psi with no problem. so tried it out just make sure u dont have any boost leaks cus a boost leak will give close to the same problems depending on how much ur actually leaking.:2f2f:

Exactly what it feels like....rev limiter. We'll, i bought some DENSO plugs today at Autozone! Gonna put these suckers in tomorrow and let you guys know how it went.

[ford_o]

change my plugs all problems solved now i just have a heater hose leak lol!!!!!!!!!

[fliprayzin240sx]

BCPR7ES gapped down to .030, runs $1.20 a pop and I changed them every other oil change.

[91drftr]

good to hear problem solved, also those sparkplugs work great too as long as you gap them to that spec he mentioned.