Honda Civic Wagon only gets 7mpg!!!....why???
#21
02-26-2012, 10:59 AM
You shouldn't have needed to take anything apart to get to the computer, just to see the light. But yes, that circuit board is the computer for your Honda. Sounds like you did right. 3 blinks, repeating, is for the MAP sensor, like mk378 said. The number of blinks = the code number.
To answer your question, the transfer case contains the differential. It is what allows the transmission in front to transfer power (via the driveshaft) to a gearbox in the back that will give power to the rear wheels.
As mk378 said, DEFINITELY do not adjust the idle screw. If the MAP sensor is bad, or if the hose that goes from the sensor to the manifold is damaged, it will cause that sensor to send bad data to the computer. Your air/fuel calculations will be badly off, which could cause bad fuel economy. It could be running very very rich right now.
A blown head gasket is possible, but consider it a secondary problem right now if it's actually blown. Lets first see if you can take care of the MAP sensor and clear that code from the computer, then see how it performs.
I can't seem to find a manual that is specific to a wagovan. I'd look at anything that pertains to an 88-91 Civic because despite body differences, the engines were pretty much the same.
To answer your question, the transfer case contains the differential. It is what allows the transmission in front to transfer power (via the driveshaft) to a gearbox in the back that will give power to the rear wheels.
As mk378 said, DEFINITELY do not adjust the idle screw. If the MAP sensor is bad, or if the hose that goes from the sensor to the manifold is damaged, it will cause that sensor to send bad data to the computer. Your air/fuel calculations will be badly off, which could cause bad fuel economy. It could be running very very rich right now.
A blown head gasket is possible, but consider it a secondary problem right now if it's actually blown. Lets first see if you can take care of the MAP sensor and clear that code from the computer, then see how it performs.
I can't seem to find a manual that is specific to a wagovan. I'd look at anything that pertains to an 88-91 Civic because despite body differences, the engines were pretty much the same.
#22
02-27-2012, 06:26 AM
Do as suggested re the MAP sensor. Have you tried the Checker auto parts store on the south end of Taos? Maybe they'd be more helpful with parts etc.
I'll try to remember to ask my friend if he knows of any good mechanics/shops in town.
I'll try to remember to ask my friend if he knows of any good mechanics/shops in town.
#23
02-27-2012, 01:38 PM
Blink 3 times, pause, blink 3 times, pause, etc. is a code 3. This is the MAP (manifold absolute pressure) sensor. (That can be found by looking in the sticky post "ECU Trouble Codes" at the top of this forum. Look in the "OBD0" section, which concerns models 1988 to 1991).
The MAP sensor detects the air pressure in the intake manifold. Combined with the rpm, the computer will know how much air is entering the engine. This is critical so it can drive the fuel injectors in order to meet that air with the proper amount of fuel.
My Civic is also a 1991, so I took a few pictures of it to show the sensor. It is mounted on the firewall near the center of the car. The first picture shows the screwdriver pointing to the sensor itself, it's black plastic and mounted on the underside of the bracket. Check that the 3-wire plug is plugged in as shown. The sensor is about a $200 part but they rarely go bad, so don't rush out and buy one just yet. It's more likely there is a problem with the hose that connects it to the engine. This hose (if original) has "21" stamped on the side and goes over to the left (driver's side) and down to the base of the throttle body as shown in the second picture. Note that it is spliced to a hose with a yellow stripe on my car; I don't know if that is factory or not. You should have a schematic of the hose connections attached to the underside of the hood as shown in the third picture. Inspect the hose and make sure it is connected properly and in good condition (not cracked or leaky).
Your car may be slightly (or significantly) different. I think the 4WD model used basically the same 1.5 liter DX engine package but the California model (if that's what you have) has some additional parts for pollution control.
Do not turn any screws. The stuff in that old book is for carbuerator engines. The EFI system practically adjusts itself, unless there is a fault somewhere.
The MAP sensor detects the air pressure in the intake manifold. Combined with the rpm, the computer will know how much air is entering the engine. This is critical so it can drive the fuel injectors in order to meet that air with the proper amount of fuel.
My Civic is also a 1991, so I took a few pictures of it to show the sensor. It is mounted on the firewall near the center of the car. The first picture shows the screwdriver pointing to the sensor itself, it's black plastic and mounted on the underside of the bracket. Check that the 3-wire plug is plugged in as shown. The sensor is about a $200 part but they rarely go bad, so don't rush out and buy one just yet. It's more likely there is a problem with the hose that connects it to the engine. This hose (if original) has "21" stamped on the side and goes over to the left (driver's side) and down to the base of the throttle body as shown in the second picture. Note that it is spliced to a hose with a yellow stripe on my car; I don't know if that is factory or not. You should have a schematic of the hose connections attached to the underside of the hood as shown in the third picture. Inspect the hose and make sure it is connected properly and in good condition (not cracked or leaky).
Your car may be slightly (or significantly) different. I think the 4WD model used basically the same 1.5 liter DX engine package but the California model (if that's what you have) has some additional parts for pollution control.
Do not turn any screws. The stuff in that old book is for carbuerator engines. The EFI system practically adjusts itself, unless there is a fault somewhere.
I was told at Reilly's auto store mine was 1.6 litre engine, The guy was more helpful than the one at Autzone who basically ignored me. The Reilly guy sold me some new spark plugs and told me the gap should be 44 on the little metal gauge he gave me. I showed him what socket wrench set I had and he then sold me the wrong thing to take out the carbonned up plugs and put in the new spark plugs so i have to go back and get a longer tool.
I am a little hesitant to put in another set of new plugs as long as I keep having this problem, though.
I am hoping his information about the spark plug gap is correct given he was wrong about the tool i needed. Does anybody know what the correct gap should be on this vehicle?
Yes, I did not adjust anything yet, it is just that the idle runs so darn high, it doesn't sound right at all. Perhaps, this is also due to a faulty MAP sensor or hose?
I also tried the Lucas fuel injector cleaner/lubricant as well for whoever it was that suggested it. Some guy at the store also suggested I try something called Mystery Oil, but I already have a mystery so i did not want to add another one.....lol....!
I also am now having an issue with the seatbelts ....they do not move up and over the shoulder any more ....after the last guy worked on car they were sporadically working now and then, but now they are stuck in forward position and the darn beeping seatbelt alert is on ALL the time while I drive and it is driving me nuts (and believe me at this point, 'nuts' is a short drive from where I am at the moment!)....is there anyway for me to either fix the seatbelts or disconnect the alert?
Also at the same time after this guy worked on the car, the temp gauge indicator also began working intermittently ....any way I can fix that as well.....maybe a loose wire perhaps but where so I look for it? Maybe it is a loose wire with the seatbelts too, but since I have no home computer and my friend with one does not return my calls ....I am flying blind here. And no, I have no atm card or credit card so buying a manual online is out of question. It is a shame you don't have the manual for the car I have in the sticky ....I am not sure which one you suggested was like the one I have but different body ....but no matter I cannot download it myself anyway.
Anyway, I will try and look for the MAP sensor and the hose and see if I can make the blinking light stop blinking. Anyone who can help me with the incessant seatbelt alert would be greatly appreciated.
If I DID have a faulty MAP sensor, would I have to order this through a dealership or could the guy at Reilly's auto store order this for me???
Could they be found in auto salvage yards for cheaper than 200 bucks?
Thanks so much EVERYONE for your helpful advice and suggestions....I do appreciate it!
Cal_Gurl
Last edited by California_Gurl; 02-27-2012 at 01:41 PM.
#24
02-27-2012, 01:53 PM
First and foremost, you'll need to get a replacement hose. Its just a vacuum line. Go back to the auto store and ask for some vacuum line. Most places will sell it by the foot. (Its cheap.) ... (This assumes that it is able to be attached. If the little fittings are broken off, this might be a problem.)
Some spark plugs come pre-gapped. Just use that tool to make sure it sits right there at .44 or as close as possible. And yes, it sounds like you will need an extension to get that spark plug out.
Fix the hose for the MAP sensor first. Then reset the computer by unplugging the battery for a few minutes or removing the 7.5 amp backup fuse in the under hood fuse box. (At least, I believe it has the same fuse as the newer ones.)
Once the hose is fixed and the computer is cleared, start it up and let it idle for a few minutes (to calibrate the computer's air/fuel calculations), then drive a little. See if the check engine light comes back on. If it runs much better after that, change out the plugs and it might run even smoother.
Again, if the MAP sensor is not sending the right signals to the computer, the idle will be all kinds of messed up. I wouldn't doubt that it idles high. Vacuum system problems do strange stuff to idles.
If the MAP sensor does turn out to be faulty, you could start with a junkyard sensor. Junkyard electronics are usually not recommended as they can get wet from rain because the car is trashed, but if you can find one to at least try, it would be much cheaper than a new one from the stealership or an aftermarket one.
Some spark plugs come pre-gapped. Just use that tool to make sure it sits right there at .44 or as close as possible. And yes, it sounds like you will need an extension to get that spark plug out.
Fix the hose for the MAP sensor first. Then reset the computer by unplugging the battery for a few minutes or removing the 7.5 amp backup fuse in the under hood fuse box. (At least, I believe it has the same fuse as the newer ones.)
Once the hose is fixed and the computer is cleared, start it up and let it idle for a few minutes (to calibrate the computer's air/fuel calculations), then drive a little. See if the check engine light comes back on. If it runs much better after that, change out the plugs and it might run even smoother.
Again, if the MAP sensor is not sending the right signals to the computer, the idle will be all kinds of messed up. I wouldn't doubt that it idles high. Vacuum system problems do strange stuff to idles.
If the MAP sensor does turn out to be faulty, you could start with a junkyard sensor. Junkyard electronics are usually not recommended as they can get wet from rain because the car is trashed, but if you can find one to at least try, it would be much cheaper than a new one from the stealership or an aftermarket one.
#25
02-27-2012, 02:24 PM
On the battery (+) terminal there is a little fuse block with two 30A fuses and a plug with two small wires (in addition to the big wire that goes to the starter). The fuses and small wires are for the seat belt motors (left and right). Make sure that is all hooked up properly, and the seat belts should work again. Do not drive with the seat belts in the down position, going through the windshield is no fun. If you can get them to go up once but they don't work consistently, wait until they are up then unplug the larger plug on the seat belt control box under the dash in the very center of the car (on top of the "hump" in the floor. The plugs are on the right side of the box and you will need to remove a trim piece to reach them). They will not move again and the beeper should not sound. Honda has a lifetime warranty on the seat belt system-- if it is a complicated problem you could go to a dealer.
Temperature gauge is operated by a sensor underneath the distributor (the part on the right side of the engine which is wired to the spark plugs). There are two sensors there, the one toward the back with a single wire is for the gauge. If the wire is unplugged or not making good contact, the gauge will stay at cold.
Carbon on the plugs doesn't mean the plugs are bad, it means the engine is not working properly. Once the engine is working properly the carbon should burn off by itself.
Temperature gauge is operated by a sensor underneath the distributor (the part on the right side of the engine which is wired to the spark plugs). There are two sensors there, the one toward the back with a single wire is for the gauge. If the wire is unplugged or not making good contact, the gauge will stay at cold.
Carbon on the plugs doesn't mean the plugs are bad, it means the engine is not working properly. Once the engine is working properly the carbon should burn off by itself.
Last edited by mk378; 02-27-2012 at 02:37 PM.
#26
02-27-2012, 02:27 PM
Blink 3 times, pause, blink 3 times, pause, etc. is a code 3. This is the MAP (manifold absolute pressure) sensor. (That can be found by looking in the sticky post "ECU Trouble Codes" at the top of this forum. Look in the "OBD0" section, which concerns models 1988 to 1991).
The MAP sensor detects the air pressure in the intake manifold. Combined with the rpm, the computer will know how much air is entering the engine. This is critical so it can drive the fuel injectors in order to meet that air with the proper amount of fuel.
My Civic is also a 1991, so I took a few pictures of it to show the sensor. It is mounted on the firewall near the center of the car. The first picture shows the screwdriver pointing to the sensor itself, it's black plastic and mounted on the underside of the bracket. Check that the 3-wire plug is plugged in as shown. The sensor is about a $200 part but they rarely go bad, so don't rush out and buy one just yet. It's more likely there is a problem with the hose that connects it to the engine. This hose (if original) has "21" stamped on the side and goes over to the left (driver's side) and down to the base of the throttle body as shown in the second picture. Note that it is spliced to a hose with a yellow stripe on my car; I don't know if that is factory or not. You should have a schematic of the hose connections attached to the underside of the hood as shown in the third picture. Inspect the hose and make sure it is connected properly and in good condition (not cracked or leaky).
Your car may be slightly (or significantly) different. I think the 4WD model used basically the same 1.5 liter DX engine package but the California model (if that's what you have) has some additional parts for pollution control.
Do not turn any screws. The stuff in that old book is for carbuerator engines. The EFI system practically adjusts itself, unless there is a fault somewhere.
The MAP sensor detects the air pressure in the intake manifold. Combined with the rpm, the computer will know how much air is entering the engine. This is critical so it can drive the fuel injectors in order to meet that air with the proper amount of fuel.
My Civic is also a 1991, so I took a few pictures of it to show the sensor. It is mounted on the firewall near the center of the car. The first picture shows the screwdriver pointing to the sensor itself, it's black plastic and mounted on the underside of the bracket. Check that the 3-wire plug is plugged in as shown. The sensor is about a $200 part but they rarely go bad, so don't rush out and buy one just yet. It's more likely there is a problem with the hose that connects it to the engine. This hose (if original) has "21" stamped on the side and goes over to the left (driver's side) and down to the base of the throttle body as shown in the second picture. Note that it is spliced to a hose with a yellow stripe on my car; I don't know if that is factory or not. You should have a schematic of the hose connections attached to the underside of the hood as shown in the third picture. Inspect the hose and make sure it is connected properly and in good condition (not cracked or leaky).
Your car may be slightly (or significantly) different. I think the 4WD model used basically the same 1.5 liter DX engine package but the California model (if that's what you have) has some additional parts for pollution control.
Do not turn any screws. The stuff in that old book is for carbuerator engines. The EFI system practically adjusts itself, unless there is a fault somewhere.
Okay ...I just went outside in the parking lot and looked at the MAP sensor ...there is a truncated hose that comes out about an inch and then, nothing! There is no hose attached to it at all! Someone must have removed it. I see the little black plastic device and it is still there ....i wonder if they removed it because it quit working??? Also Next to the solenoid valve (which also has no working hose) is a blank space ...and then this little plasticy thing on end that looks like it does nothing, but underneath it has a long hose that looks relatively newer than the rest that come out at the bottom ....it just looks like it is inserted into a hose-hole but doesn't go anywhere and just hangs down loose ....it is about 18 inches long or so....I have no idea why it is there.
So, I have no MAP sensor hose ....this would appear to have answered the question then if you are saying that without this, the fuel injectors would not work properly and I would not get good fuel mileage ...which of course I do not as we all know.
So, how to proceed? should I try to attach this hose that just hangs down to the MAP and then to the hole in the engine where it goes? Or do I need a special hose that has some kind of electrical thing in it that sends information to computer?
If I try this and it doesn't work to stop the three light blinking routine in computer, do I need to order a special hose (withyellow stripe perhaps?) for this device or should I assume that the MAP sensor is broken?
Also, what about the solenoid valve next to it ....that looks like it needs a new hose but where do I attach THAT to ....oh yeah, I will look at diagram ...but can you tell me what this device does and how not having connected can affect vehicle?
Thanks so much for your time and help ...I really am thankful for it .....i hope you can help me further to perhaps remedy this problem. Or anybody else that reads this as well.
Thanks again.
I will come back tomorrow and see what response there are and I will wait to put in new spark plugs.
Cal_Gurl
#27
02-27-2012, 02:45 PM
Often mice or squirrels will get under the hood and literally eat the hoses and / or wiring (I'm not sure why, ask the next one you see). What remains would look chewed. Sometimes, just to torment the car owner, they'll bite one little hole in the side then go away. If it isn't carrying a liquid (such as sweet, sweet antifreeze) you may not notice the leak.
I think the hoses are ordinary and you can just buy about 3 feet of vacuum hose from a parts store and replumb the whole thing (following the diagram on the underside of the hood, is that still there on your car). My car has a Tee fitting and some funky device on the other side of the tee up under the bracket-- it's dark here now but I'll try and investigate tomorrow.
I think the hoses are ordinary and you can just buy about 3 feet of vacuum hose from a parts store and replumb the whole thing (following the diagram on the underside of the hood, is that still there on your car). My car has a Tee fitting and some funky device on the other side of the tee up under the bracket-- it's dark here now but I'll try and investigate tomorrow.
Last edited by mk378; 02-28-2012 at 08:29 AM.
#28
02-28-2012, 08:04 AM
They might ask what size vac hose, which is the inside diameter...1/8",5/16"..and like he said is sold by the foot. You can use a razor knife to slice the hose where it connects to a fitting so as to lessen the chace of breaking it;if the fittings are plastic,they'll be brittle/fragile from age. Check all and replace as necessary.
If you were still in Ca,it'd probably be fixed by now...lots of car enthusiasts there.
If you were still in Ca,it'd probably be fixed by now...lots of car enthusiasts there.
#29
02-28-2012, 01:22 PM
Thanks for the info.
Does anyone know how I can rectify the seat belt/seat belt alert problem?
Too windy to work on car, today; I'll try tomorrow and get back to you all on whether the hose works for the MAP sensor.
Does anyone know how I can rectify the seat belt/seat belt alert problem?
Too windy to work on car, today; I'll try tomorrow and get back to you all on whether the hose works for the MAP sensor.