Causes of Bogging after Operating Temp

[Matt_240]

My car bogs. bad. around after 15-20mins of driving and car reaches operating temperature. buckles, chokes, fuel cuts, you name it, it does it.

i know there is closed loop/open loop. what are the components that change after closed loop?

i know the o2 sensor is one. anything else?

Any help is appreciated.

[Matt_240]

any advise would help. thanks

[Al_S14]

waht year is your car? does power suddenly drop off when you haul ass then return moment later and jsut pick back up as if nothing happend?

it seems i got same problem but nobody seems to know the fix

[IvanAtSPRacing]

Your car will run on an open loop program untill it reaches normal operating tempature. It switches to closed loop at this point. It relies on feedback from the O2 sensor at this time. If the O2 sensor is not reading right, then your car wont run right. Does your car run ok at WOT once up to temp? At WOT the ECU switches back to open loop and doesnt use the O2 for adjustments.

[sciamop]

It takes 20 minutes to reach operating temp in Hawaii? IIRC, you can just unplug the 02 sensor and the car will be in open loop mode = bad gas mileage but better than junk signal.

My car acts this way sometimes too. I'll be troubleshooting it in the spring... I'll post my findings.

Todd
93 Coupe
91 SE-R

[Matt_240]

i know the o2 sensor isnt' the only thing. the coolant temp, and other things are relied upon in closed loop as well.

when it starts bogging like that, i will disconnect my 02 sensor and see if that works. in the meantime im gonna change my ecu and coolant temp sensoor.

any other suggestions as to what it could be? thanks for the help guys. im sure lots of people have this same problem.

[idlafie]

Originally Posted by Matt_240

My car bogs. bad. around after 15-20mins of driving and car reaches operating temperature. buckles, chokes, fuel cuts, you name it, it does it.

i know there is closed loop/open loop. what are the components that change after closed loop?

i know the o2 sensor is one. anything else?

Any help is appreciated.

When your bogging problem occurs, does it occur during acceleration and braking? Do your dash lights come on & the engine dies on you or seems like it's gonna die on you??

If you are getting weird symptoms like the above, check the ground connections on the rear driverside portion of the engine block right above the O2 sensor. Nissan in their ultimate wisedom grounds several components at that point - fuel pump/distributor coil/etc. If one of those ground wires goes bad, (and it can, remember it's right above the exhaust manifold where it gets really hot - heat & wires are not a good combination - wire connections get brittle & break), then you could have an intermittent short in one of your ground wires. Easiest way to fix it is find a new grounding grommet & cut the existing one off & solder all the ground wires to your new grommet. That should fix your bogging problems.
Anyhow, hope this helps...
ID

[Matt_240]

Originally Posted by idlafie

When your bogging problem occurs, does it occur during acceleration and braking? Do your dash lights come on & the engine dies on you or seems like it's gonna die on you??

If you are getting weird symptoms like the above, check the ground connections on the rear driverside portion of the engine block right above the O2 sensor. Nissan in their ultimate wisedom grounds several components at that point - fuel pump/distributor coil/etc. If one of those ground wires goes bad, (and it can, remember it's right above the exhaust manifold where it gets really hot - heat & wires are not a good combination - wire connections get brittle & break), then you could have an intermittent short in one of your ground wires. Easiest way to fix it is find a new grounding grommet & cut the existing one off & solder all the ground wires to your new grommet. That should fix your bogging problems.
Anyhow, hope this helps...
ID

it only occurs during accelration. and it seems like its gonna die cause it jerks so much but if i accelrate through it, its ok sometimes. yeah, the ground connections by the manifold are definitely a possibility. where should i cut the ground wires from though?

thanks for the help

[idlafie]

Originally Posted by Matt_240

it only occurs during accelration. and it seems like its gonna die cause it jerks so much but if i accelrate through it, its ok sometimes. yeah, the ground connections by the manifold are definitely a possibility. where should i cut the ground wires from though?

thanks for the help

Your problem occurs ONLY during acceleration?? Could it be possible that your car is NOT getting enough fuel or air mixture??. Could be a screwed up fuel pressure regulator OR vacuum line running to it or a lagging fuel pump. Maybe even PCV valve..who knows...
What RPM band does your problem seem most apparent? Does it clear up when you go to Wide Open Throttle? Your bogging could be due to a stuck EGR valve or carbon buildup in your EGR valve or a clogged line that runs behind the EGR to the exhaust manifold.
Troubleshooting this problem is gonna be a royal BEOYTCH!!...Find yourself someone extremely knowledgeable in tuning 240's...you're gonna need their expertise!!
Anyhow, hope this helps..
ID

[Matt_240]

Originally Posted by idlafie

Your problem occurs ONLY during acceleration?? Could it be possible that your car is NOT getting enough fuel or air mixture??. Could be a screwed up fuel pressure regulator OR vacuum line running to it or a lagging fuel pump. Maybe even PCV valve..who knows...
What RPM band does your problem seem most apparent? Does it clear up when you go to Wide Open Throttle? Your bogging could be due to a stuck EGR valve or carbon buildup in your EGR valve or a clogged line that runs behind the EGR to the exhaust manifold.
Troubleshooting this problem is gonna be a royal BEOYTCH!!...Find yourself someone extremely knowledgeable in tuning 240's...you're gonna need their expertise!!
Anyhow, hope this helps..
ID

i capped off my egr. but i will look into the fuel pump/fpr

wire harness didn't change anything.

[Prelude Guy]

Can you give any details on how to take off and cap off the EGR valve on a KA24E motor?

I am having the same problem. It happens when the car is cold too though.

Thanks,

Andy

[idlafie]

Originally Posted by Matt_240

i capped off my egr. but i will look into the fuel pump/fpr

wire harness didn't change anything.

HUH?? What did you do THAT for?? Did you know that your ECU programming takes into consideration that exhaust gases from your EGR are SUPPOSED to be recirculated back into your intake manifold to assist with engine management AND pollution control?? If the ECU isn't finding those recirculated gases the ECU will try to compensate for this. And as a result of this, your engine performance will suffer...as you are now discovering. Did your bogging problems start before OR after you disconnected your EGR?? If it was before, then your problems were due to a defective sensor and NOT your EGR. Just because a sensor isn't throwing a code, doesn't mean it hasn't gone bad. With today's modern engines, and their electronics/sensors, troubleshooting the problems are becoming more & more difficult. Trouble codes help but aren't exactly right at times.
Don't believe me?? Then read the following article posted by a pro...
http://www.asashop.org/autoinc/july2002/techtotech.cfm
Anyhow, hope this helps...
ID

[Matt_240]

f*ck it. im tired of this ka motor. im gonna go sr.

[monkeyspeed]

check the timing

[Matt_240]

change the cts and o2. no change.

gonna replace part of the harness next. also, switch out distributors. will update.

[Yuri]

What kind of engines does everyone have? Mine is an SR that I'm experiancing the problem with. I had the wiring harness thoroughly checked and repaired, replaced a bad coil, and replaced a clogged cat. It still bogs...

[Matt_240]

ok, sent the car to an electrical shop to redo part of the harness.

will update.

[fliprayzin240sx]

Im willing to bet that its your water temp sensor. My car had the same issue. basically, ecu thinks its running cold so its dumping more fuel that its supposed to at operating temp causing you to bog.

[Al_S14]

why does it do it only in high rpm...above 4/5k . if it sprays more fuel then needed it will jsut run rich not misfire hmmm

and if ECT was faulty wouldnt engien temp gauge read wrong?

[Maxtype 240]

Originally Posted by Al_S14

why does it do it only in high rpm...above 4/5k . if it sprays more fuel then needed it will jsut run rich not misfire hmmm

and if ECT was faulty wouldnt engien temp gauge read wrong?

Coolant Temp Sensor (CTS) and the cockpit temp gauge are 2 different sensors.

The best way to check CTS is an OBD scan tool for 95-98 cars...

Jesse

[Al_S14]

yeah i was jsut about to tell you about it... did it this morning with Honda PGMTester. its working to spec . still need to check fuel pressure and coil , hope its one of those 2

[eurosil80]

my ka24e has the same problem...except now....it floods when i shut it off....and wehn i come back to start it it wont start up the first couple of cranks.... The temp sensor seems logical...ill give that a try.... what are the main causes of floodin?

[DrSiD202]

my car boggs in every gear right at 4k rpm .. i'll watch your thread till you find an answer. everyone i know is baffled by my problem.

maybe ill start my own thread, noone has posted in a month, here.

[c0axiL]

i drove a dsm that had a similar problem. it started off fine but once it warmed up it the problem started. checked the whole ignition system and most of the fuel system but they didnt work. after a while of driving it like that it became a constant problem even when the car was cold. it ended up being a problem with the plug wires, even though when they were current tested they were fine. im not sure if this can help you in anyway, but good luck wiht your prob.

[SxMachine]

Has anyone found a solution 2 this prob yet i'm having similar issues. I've replaced injectors, fuel filter, fuel pump has around 1K miles, distributor cap, plugs, and wires so far. Whats left that u guys haven't tried?

[F3600]

Did you check, tested the water temp sensor ? Its a simple procedure in the FSm give it a look

[Al_S14]

Originally Posted by SxMachine

Has anyone found a solution 2 this prob yet i'm having similar issues. I've replaced injectors, fuel filter, fuel pump has around 1K miles, distributor cap, plugs, and wires so far. Whats left that u guys haven't tried?

well i fixed my problem. dont know how it happend but my car was nearly 15 degrees off timing. maybe previous owner replaced the distributor and didnt sent it correctly but it more then fixed the problem. first time i drove it after taht it was liek a new car .... got an awesome kick in the pants in first. almost like Vtec but now that i've had it running right for few weeks it doestn feel as quick.

[Yuri]

Mine ended up being a blown turbo gasket. On both sides of the turbo!

[ledzeppelin240]

I would check the ingition system, fuel, and O2 sensor. If everythig there checks out test the EGR valve and EGR control valve, then make sure the wiring harness where it connects to the ecm has a good connection. The CAS is located in the distributor just to clear that misinformation up. It uses an LED and a photo diode to transmit a digital signal to the ECM.

[einherjar]

Originally Posted by Matt_240

My car bogs. bad. around after 15-20mins of driving and car reaches operating temperature. buckles, chokes, fuel cuts, you name it, it does it.

i know there is closed loop/open loop. what are the components that change after closed loop?

i know the o2 sensor is one. anything else?

Any help is appreciated.

Hey Matt
Did you fix the problem? if so, what was it? :S