finally drove her but i have a problem

[s13point5]

okay so i finally drove her tonight. it felt good to be back in the car on the streets but she isnt driving right. my rpms are guestimates since my tach stop working all of a sudden yesterday. the car feels like its hitting fuel cut or something around 3000 rpms (again this is just a guestimate). whats happening is ill put her in first and go and once i hit 3000 or so rpms she will bog like im hitting fuel cut. shift to second same. 3rd gear when im going slow will let me keep my foot on the gas and go for a little bit but again when i hit that 3000 or so rpms she will bog as well in 3rd. i adjusted the tps to be .5v as i have read on here. anyone else have any ideas what the problem is?

[s13point5]

oh and im not getting a check engine light. maybe its a bad maf? how do i check if the maf is bad. i dont have another one readily available to swap in. i also didnt shield the maf wires when i extended them

[rb25drag]

Do you have a wideband?

It sounds to like either a boost leak or a MAFS problem.

Do you have a boost gauge?

[Shocker]

yeah sounds like a MAF or boost leak issue. I'm leaning towards MAF though.

[s13point5]

Do you have a wideband?

It sounds to like either a boost leak or a MAFS problem.

Do you have a boost gauge?

i do not have a wideband but yes i do have a boost gauge.

how do i check to see if the maf is bad? and where can i get a S1 maf at?

[cdorhout]

Sounds like a definate boost leak to me. Plus that's alot easier to check than a bad MAF. I'd start there.

[Sil240]

Yeah I finally drove my car yesterday.And I have the same exact problem.But I have yet to adjust the TPS.It turned on and idled and I drove it down the block and turned around. But it kept on feeling like it wanted to shut off.So i had to keep it up with the gas pedal.

When I would get on the gas about 25% (guessing) it would bogg just like yours.I haven't hooked up my tach as yet so not sure what RPM's I was at.

[s13point5]

Yeah I finally drove my car yesterday.And I have the same exact problem.But I have yet to adjust the TPS.It turned on and idled and I drove it down the block and turned around. But it kept on feeling like it wanted to shut off.So i had to keep it up with the gas pedal.

When I would get on the gas about 25% (guessing) it would bogg just like yours.I haven't hooked up my tach as yet so not sure what RPM's I was at.

that sounds exactly like my problem. ill check for a boost leak. anyone have a link on how to make a good boost leak tester? i had a link but lost it

[Shocker]

Sounds like a definate boost leak to me. Plus that's alot easier to check than a bad MAF. I'd start there.

Definitely easier to check, just check the main couplers first, then all the vac lines... hopefully thats the issue.

[s13point5]

Definitely easier to check, just check the main couplers first, then all the vac lines... hopefully thats the issue.

i pray thats the case. ive been fed up with the little **** that has came up since i put the motor in the car.

me not having a exhaust or downpipe on the car wouldnt cause the problem would it? i have to try and get it running right and take her loud *** down to the shop to get the downpipe cut cocked and welded.

[wawazat8402]

My car woudnt start after it warmed up with no downpipe. There was too much fresh air hitting the O2 sensor making it dump in way too much fuel.

The 25% throttle bogg sounds just like a huge boost leak. My car did the exact same thing when I blew the coupler off.

To make a boost leak tester, just get a PVC cap.

Like this:

Then get a valve stem:



Drill a hole in the PVC cap and install the valvestem. If you want, you can also drill another hole and install a pressure gauge into the cap as well.

Get one that doesnt read that high though. If you can find one that reads to 30psi, it will give you better resolution.

Just make sure everything you install in the cap is well sealed. Then install the cap on the turbo inlet and use an air compressor to pressurize the system. Watch for leak down on the gauge.

[Sil240]

Cool thanks for the How to:

I'll hit up the HO-Depot when I get outta work.

That would be cool if it was just a boost leak.Much easier on me. lol

[craz4240]

Sounds like a boost leak,dirty or bad mafs to me.

It's running rich under full boost which seems like a fuel cut,if it's a leask it is no doubt somewheres between the MAFS and TB.

[Sil240]

I've cleaned my MAFS and tried it on a friends car. So hopefully its just a combo of boost leak and TPS not calibrated.

But his might be mafs, i had a friend with a dirty maf that had the same symptoms.

[s13point5]

so im sitting at work stressing about whats going on with the car and i remember that my boost gauge is reading 15-17 vacuum. what is a normal vacuum reading? i think i read somewhere that its suppose to be 20-24

[slw240sx]

you have my number, call me, and when i dont pick up call me another 4 times in a row.

[Shocker]

so im sitting at work stressing about whats going on with the car and i remember that my boost gauge is reading 15-17 vacuum. what is a normal vacuum reading? i think i read somewhere that its suppose to be 20-24

Your vac is fine, doesn't have much to do with your issue.

[s13_240_rb20]

To all of you with "bogging" problems, I hope and pray you will do two things: check for clean spark plugs ANDDDDD unplug your o2 sensor.

Don't ask questions or think about the theories (like I did), these are free tests!!! I lost a year to downtime because one day my spark plugs were good, then I had a o2 wiring problem and it bogged out, and quickly fouled my plugs. The fouled plugs went undetected for a week of "head-scratching" then I just parked the car and barely touched it for a year....

After this year's spring hit, I checked the plugs, replaced them, troubleshooted, checked them again and they were fouled again, .......anyways, I learned to keep checking the dang things!!! eventually, while keeping good plugs, I managed to figure out the bogging problem and now she runs...

--TJ

[S14-NEO]

from the sound of it, it sounds like its in limphome mode..usually is the resuly of a bad MAF.....the very first thing i would do is go and get some electrical contact cleaner (MAKE SURE ITS ELECTRICAL) and clean off the hotwire and alloww to air dry for at least 15 minutes. give that a shot, there is a 50/50 shot that will fix your issue.if it doesnt than sadly you may have to source a replacement MAF. it could be a boost leak but it would have to be serious leak to just fall on its face at 3000rpms...i mean it would be one you could hear with little trouble.

[s13point5]

ive already sourced a replacement maf. i have one being set from user gawdzilla. im hoping it works tho because it was a RB20 maf. but what i have read, the RB20 is also a j60 and should work.

[s13point5]

so i tried cleaning the maf today. gives me something to do while im waiting on the maf to come in and i tried to take her around the block again. didnt help. it seems as the problem happens whenever she gets into boost. drivinig during vacuum is fine but once she gets 1psi into boost she will bog hard and start bucking. does that still sound like a maf problem?

[S14-NEO]

do you have a wideband, if so what does it reads when it happens?

[rb25drag]

Will the car free rev fine?

[s13point5]

no wideband and the car will free rev until boost then it cuts out/bogs

[rb25drag]

That doesn't sound like MAF to me.

Do you have a fpr? Fuel pressure gauge? Have you checked the timing? Also what are spark plugs gapped at?

[s13point5]

i do not have a adjustable FPR. i did however just put in a order for a nismo FPR and a gauge from jegs because i do have a upgraded puel pump (power enterprise 210 fuel pump). i read the thread from carl H over on 240sxforums.com. plus i found this thread where he states the car bogs when he gets into boost which is pretty much what mine is doing

zerothread?id=195361

as for the timing, read this thread to see my problem with the timing zerothread?id=195361

ill have to recheck my spark plug gap but im pretty sure they are gapped at factory specs. i did them a long time ago (dont worry the car hasnt ran till now).

[s13point5]

okay i put on a nismo FPR today and a gauge. adjusted it to 36psi at idle. took her around the block and im still experiencing problems. once she sees boost, she bucks and bogs. im really hoping this is a maf problem but i dont know. new maf should be in wednesday

[ripracer]

Still sounds like a boost leak. Yesterday at the track I had a nice size hole almost the size of a dime and it would free rev sometimes but as soon as I got out on the track it bucked and sputtered.

Do the boost leak test you'll be surprised where you'll find them and how many you might actually have.

[DriftX]

set timing... sounds like a maf issue to me, but you should pressure test your system before you even drive it the first time

[rb25drag]

Double check the timing. If it will Free Rev I really don't see it as a MAF problem. Its either timing or boost leak.