My car is bogging out, only when warmed up

I have a slight problem with my fuel system. I'll give you some hinters, and i'm open to all suggestions:


Already tested/replaced:

Spark Plugs
Plug Wires
Dist. cap and rotor
Fuel Pump
Fuel Filter
Ignitor
Ignition Coil

All are either OEM honda parts or have been tested by a certified mechanic (which doesn't mean **** these days, but he did confirm that the fuel pump is working perfect).

Yesterday, I hooked up my A/F gauge (autometer) to see if it would help me identify anything. I know that the results of this particular gauge are worthless at times, but I did notice something particularly interesting.

The light show is fine until the car starts bogging out. Then the gauge reads PURE richness. I mean the light goes all the way to the rich end.

Are there ANY suggestions as to what this might be? I am thinking ECU or o2 sensor, but i'm not really sure. The AF gauge has led me to believe that it is 100% a fuel problem. What would cause my car run extremely rich while bogging? It no longer has any serious modifications to it.

Some history: I used to run the SMC+ piggy back. I had installed the block resisters in the fuel injection wires. The bogging was very evident, until I removed these resistors. I ran fine for about 6 months, without problem, until I lose control of the car and hit the undercarriage. This was a light hit, but the bogging began immediately again. I've checked the injector wires with my multimeter, and I am reading ~26 across the board. What could this possibly be?

 

You will need to test your o2 sensor performance. hook up a dvom(digital voltmeter) and monitor o2 reading. if your reading at the rich side like above .6 - .9 create a vaccuum leak and see if voltage drops to below .2 volts. if not, your o2 sensor is lazy.

 

are you getting a CEL ? perhaps code 1 or code 41 ?

greg

 

No CELs at all

 

When you hit your under carriage, did you dent any of your exhaust components? I had a problem in my car with it bogging under load in vtec (like 4th and 5th gear) everything electrical and fuel related checked out, turned out to be the combination of the cams I was running and having a stock catback (mated to jdm 4-1 and 2.5" test pipe). ran open header and no more bogging. This would also explain your extremely rich condition.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cheap_autorepair &raquo;</TD></TR><TR><TD CLASS="quote">You will need to test your o2 sensor performance. hook up a dvom(digital voltmeter) and monitor o2 reading. if your reading at the rich side like above .6 - .9 create a vaccuum leak and see if voltage drops to below .2 volts. if not, your o2 sensor is lazy.</TD></TR></TABLE>

or you could try enrichening with propane.

either way when you lean it out or enrichen it..
and then return it to normal..
your o2 should go back to normal ranges of .3 to .6 and it should fluctute normally and rapidly.
for example when you hit the propane or open and air way it should show full rich or full lean, and when you 'fix' it..
it should go back to normal

 

I only dented the oil pan, and this was a very tiny dent at that. Hardly even the size of a dollar...i don't know if this could affect anything however.

 

ttt

 

find an auto shop that does free estimates then when they say whats wrong you say ohh thanks and BONE OUTTA THERE!

 

just to clearify a few things other people mentioned earlier...

creating a vacuum leak on a car using a map sensor would cause a rich condition, and would not lean the a/f mixture. to lean it out, pull an injector harness...

injecting propane would definatelly cause the rich condition...

i would try to help you out here, but considering i'd probably have to write a 2 page essay, i'd probably skip it this time... just start with the o2 and see if they'll give a sign of what the cause is... if you have access to a scan tool, take a snapshot of the ecu's monitoring perameters, and that'll really help.

keep in mind though, that this will not be a quick fix. the computer is constantly adjusting the a/f mixture to get the best emissions, and is able to compensate for some problems to a point that you don't even know there's a problem. when you DO notice a problem, it's cause the problem(s) are severe enough that the computer can no longer compensate. basically, you may have more than one problem contributing... ie. O2 sensors, map sensor, tps, ecu, etc...

 

A new development that may help - If it starts bogging while I am driving, and I turn off the ignition and then turn it on, it runs perfectly again for a few mins, until it starts bogging again. Any ideas?

 

ttt - come on guys...

 

what year is the car?
do you guys use the U.S.'s OBD standards in canada?

 

Both US and CDN OBD standards are the same. The car is OBD1 (1994)

 

well... let me at least list the components that may be the cause of your problem.

o2 sensor... showing the ecu a constant or biased lean condition would cause the ecu to richen the a/f mixture

tps... intermittently showing wot eventhough you're at cruise would also cause a rich condition

coolant temp sensor, showing a cold engine " " " "


map sensor- a faulty map sensor showing a high voltage causes the ecu to see wot and adds fuel to the extra air the ecu thinks it see...
a vacuum leak at the map sensor, or its hose going to the intake manifold (if it's seperate from the manifold) would also cause that....

that's all i can think of, but to really be able to tell you which one is the suspect, i'd need to look at some scan tool data of the perameters numbers at which the problem is felt. otherwise, it's hooking up a multimeter and looking at the numbers while driving...

 

I had the same problem, where the car would bog after long drives or when it's really hot. I changed my plugs, rotor and cap looked good, changed the fuel filter, and wires are fairly new.

But the other day I checked the timing at it was off, set it back to factory. Got a B&M FPR and gauge (was 50 at idle), turned it down to 40 at idle (with vacume on, 50 with it off... reason I was so high is cuz of the walbro fuel pump in my car), and recieved a new ECU w/ a custom all motor program (from iH8RICERZ). So far I haven't experienced any bogging but I have yet to drive 30+ minutes (did a lot of stop and go though so I would think the engine got pretty hot). Car is running great so far and I hope I fixed my bogging problem.

Now, I'm not sure if this will help you but just thought I'd share my story. I'm not throwing any CELs either.

Good luck with your car!

 

what kind of plug wires are you using? i was surprised how many times i've seen accelleration hesitations, bogging, stalling at idle, etc were caused by intermittent opens in just one spark plug wire. if you still experience those symptoms, i would suggest picking up a set of factory wires.

 

ttt

 

taz77 has some good ideas. try those out and you'll probably solve your issues.