My Problem: Massive Bogging

[Matt_240]

ok, ive got a 95 240sx. im getting my car painted by some sidejob guys and they took it to their house to bodywork it. after they body work it, they try to drive it and its bogging. i go over there to check it out and all through the gears it bogs. like crazy bogging. when i let the car go by itself w/o pushing throtttle, it's fine. it's when i hit the gas pedal that it bogs. 1st gear and 2nd gear is horrible. one thing that's really weird is that i left it in 1st and let it go w/o pressing the gas pedal, and it didnt die! wtf!? anyway, before you tell me to search, ive done a lot of searching. heres what i got so far:

1. Clean Mafs, TPS, AIV, all sensors
2. Check injectors
3. Check battery terminal
4. Seafoam throttle body
5. Check for loose wires
6. Check for vacuum leak
7. Entire Distributor?

i thought maybe the dust from primer got into the MAF sensor so i cleaned the MAF sensor with alcohol, but it didn't change anything. Changed the rotor but that didnt change anything either. im going to change my spark plugs tomorrow. i was wondering if anyone else had this problem and how they fixed it. id like to know what the most likely problem is cause i want to fix this asap. Thanks for any help.

[Matt_240]

oh yeah more information. my car starts fine. sometimes idle is shaky(like goin up and down from 600-900. sometimes its ok.

[twitchy]

TPS thats my guess...mines starting to do it too

[Matt_240]

TPS? are you gonna clean it? should i just clean it with alcohol as well? is your car bogging like hell?

[twitchy]

i dont know what to do with it.. Its not bogging too too bad just sometimes for now...Well have to see what happens..I want to try sparkplug wires and plugs first

[Matt_240]

ok, im gonna try spark plug and wires first. then fuel filter. then clean sensors. if that doesn't work. then. clean throttle body. if that doesn't work then i dont know.

[twitchy]

heres my 2 bits:

-changing fuel filter wakes up high end acceleration (using OEM FILTER) and goes so slowly you can hardly tell you were losing power...easy to do

-changing plugs seems to do little or nothing, i just regap and clean mine every so often..maybe a little perkier

-run some combustion chamber cleaner through the TB....idles nicer, runs stronger, uses noticeably less gas at first (although its starting to get bad again but I have an O2 sensor waiting to go in)

-fuel injector cleaner at every fill up to keep them clean

all this and the only thing I can tell affects the bogging (although again mine isnt severe and can be stopped by just hamming the gas) is the fuel injector cleaner...maybe ones clogged or something...as well check your plugs when you remove them..the inner valve cover gasket can leak oil into the sparkplug area and foul it up.....

[direb0y]

funny, my car (sohc) and a friends (dohc) are doing almost the exact same thing.

something i noticed - sounds like the cat is clogged, running super rich, everything seems to run better with the intake off....

i'm thinking it has something to do w/ the maf

[Vatche]

well i had bogging problems with my sr.....and it was due to the stock ka exhaust i had on it the turbo was getting too hot....i dont know if that helps you or not

[Matt_240]

ok, just changed my plugs, fuel filter, and cleaned all the sensors. evem put in fuel system cleaner. took it out for a drive 5 min ago. i tried starting it and it had irratic idle. would just die on its own if i didn't rev it. drove it around and it was fine until my engine started to warm up. then the massive bogging started again in all gears. im kinda lost.

could it be my distributor? i changed the rotor but could it be the whole distributor assembly itself? my spark plug wires look fine. im not sure about my injectors though. anybody have any ideas?

[zero.counter]

I would check for some rotten vacuum hoses. When they become brittle and break, they may still look like they are fine, but are actually releasing the vacuum...

[Ghettokracker71]

did you mess up the connector to the MAF? I did that when I pulled mine off,and even though the actual electric meeting points were fine,the clamping system wasn't,and it was acting the same....try runing seafoam.....half into a vacumme line while the car is running....pull it off your brakes booster....then cut off the car,and put the rest into your crankcase,let it sit for an hour and drive around at NORMAL rpms until it stops smoking,that should greatly help (proble need it anyway)

Direboy could easily be right.....check your o2 sensor too,it could have some relation to this,but I highly doubt it would cause it....

EDIT:Only run seafoam a max of 500mis. before an oil change,and be warned...guys on zilvia will flame me for suggesting that and will proble say not to...


I still have a feeling its the MAF,you were talking about the primer dust and whatever,that could have easily started to kill it,and that means that cleaning it won't do you any good....can you check your ECUs code and post it?

[smellslikecurry]

my car was bogging also, does the the car smell like oil when your driving?? in my case it was the knock sensor, i think when i was trying to take out my oil filter i broke the clip for the knock sensor nad the rubber casing also ripped off, oil got on it..i just used denaturized alcohol and now its fine

[misnomer]

It could be any of a number of things. On my sister's SOHC, when it was bogging, it turned out to be a clogged catalytic converter.

[Matt_240]

changed tps, checked distributor, isn't a clogged cat, and not MAF cause i switched it out and it still did it. took it ot a shop and came to the conclusion that it might be the EGR valve. the spring inside seems to be bad and keeps it open, hence causing it to bog. im gonna have them cap it off tomorrow with a plate and see what happens. i'll let you know how it goes cause it seems like a lot of people are having this problem and cant figure it out.

[Matt_240]

ok. update:

1. changed tps - no change
2. checked o2 - fine
3. removed egr - slightly better but still almost same
4. vacuum lines dont seem to be leaking

i'll try and see if it could be the cat today.
keep the ideas coming guys cause we're starting to run out

symptoms:
1. idle bounces but steadies
2. as the car warms up, it bogs like crazy. i have to find a spot to keep the gas steady (like 3100rpm) and it'll be ok but as soon as i give it more gas, it bogs...
3. under no load, in neutral, when i steady the gas at 2k and then mash the pedal, it hesitates at 2500 rpm and then goes up.
oh yeah, and im running rich.

[nokeone]

Distributor...mine went out..did the same type of things...i would have to keep the idle at like 2500 rpms at a stop just to keep it running...talk about learning to heel toe...lol...then just wouldn't run at all...so, after doing all kids of other stuff, i changed Cap, Rotor, and Distributor itself (which sucks cause it's bank)...fixed it 100%...

but you said you checked the Distributor...so i dunno...how did you go about checking it?

[Matt_240]

a shop checked it for me.

[Matt_240]

ok, im down to the wire..heres a list of things checked so far:
1. changed spark plugs
2. switched out spark plug wires
3. changed rotor and cap - distributor
4. switched out air intake temp sensor
5. switched out MAF
6. checked intake piping for leaks
7. checked all vacuum lines
8. removed egr - to get rid of a lot of vacuum lines
9. tested continuity from sensors(tps,MAF,Intake air, coolant temp) to ecu
10. changed tps
11. changed o2 sensor
12. made more ground
13. switched out ecu
14. changed fuel filter

last things to do is switch out coolant temp sensor and entire distributor with another. hopefully i'll find someone who has one. any other suggestions are more than welcome.

[mrmephistopheles]

my problem: this should be in TECH TALK.

*moving*

[91rusty240sx]

clean your intake manifold...it does wonders...

[Matt_240]

still need help.

just changed coolant temp sensor and switched out my distributor with someone elses(& adjusted timing).

still the same. when i hold revs constant in neutral at 2000 and then, rev it up to 3000, the car bogs around 2500. when driving, it bogs when applying mid to high throttle but seems to regain control after it bogs. then it'll bog again after a little while. i dont know what to do anymore. last hope is changing out the fuel injectors and recheck vacuum lines. any other ideas guys? also, there was oil when i took out the hose that connects the valve cover to the intake. thats not normal is it?

[Ghettokracker71]

there was oil when i took out the hose that connects the valve cover to the intake

[S13Grl]

Did you put new wires on the car? How do you know it's not the wires. Bust out the ohmmeter and check your injectors. Should read 10.8 on each one. Good luck!
P.S. How's the exhaust smell?

[Matt_240]

yea, put new wires on the car. didnt test them though. i dont have an ohmmeter.

[radhaz]

Originally Posted by Matt_240

.... i dont have an ohmmeter.

I've seen them run from $15 to $30 for the inexpensive models in most autoparts stores. Multimeters can pay for themselves when troubleshooting.

[Matt_240]

any other ideas? these are new wires and i also switched them out with an extra set a shop had.

[dunno]

I'd say it was an exhaust problem if you weren't running rich. I would check your intake manifold for clogging, and after that check your exhaust with a fine-tooth comb (not literally. this might induce more problems) from the headers to the muffler.

-Matt