MFH87CivicSi

So I've got an 87 Civic Si - It starts everytime, idles for a few seconds than dies - when fuel throttle is applied it dies out completly, and I am lost.

I've changed the Air intake temp sensor, fuel filter, fuel pump, battery, dist cap, rotor, plugs - Could this be an alternator problem?

honda2k9

WHERE U LOCATED IM A MECHANIC I COULD FIX IT FOR U IF U IN NY

MFH87CivicSi

You rock - Tyvm, but I am in Oregon. =(

1grex

do you have fuel pressure?

MFH87CivicSi

i do not have a guage... if im not getting fuel pressure would it start everytime continually but than idle out?

78CITYTURBO

Could be your alternator going out? If your alternator not charging, the car idle really rough, bogging then dies. Bad gas in the tank. Do you check engine light or the pmfi light up? Check the wire plugs that goes into the ecu, sometimes those wires can have bad connection. Good luck..

MFH87CivicSi

ive heard that is an alternator is completly dead you vehicle will not start and if started, or in my case, pushed or made to start it will - but not for long... What happens when your generator runs outa life - nothing works, right?

As hard as the alternator can be to get to, its almost harder than anything else i've done to it. Its so far in there..suppose it time to change the belt as well. The thing is It could use some gasket replacement, looks like front end is leaking all over, very wet on manifold.

Heres an off the wall question - can bad oil cause it not to run?

JAF Mugen Power

I'm new here. I couldn't post too much so I pm'd you tips. Good luck.

MFH87CivicSi

Well we all gota start somewhere!

I dropped the alternator, and the main plug is coroded and fried - the other was brittle and broke - The belt was fraying so I'll be dropping a new alternator and belt on and see if the thing will but out enough juice to keep it going.

JAF Mugen Power

When you put the alternator and the belt back on, make sure the belt is not too loose or too tight, it will make the car idle up and down. Good luck.

1grex

I have been through my share of alternators on my '86. I have never had a situation where the alternator not charging directly caused the engine to die/idle rough. Now eventually, the battery will reach a point where it can no longer power the ignition circuit, this is about 8V. Back to the problem at hand, obviously there is compression enought to run. You also have spark and fuel long enough to run what, "a few seconds"? Test for spark with the good ole screwdriver in a plug wire method. The fuel pumps on these cars are outside the tank and very loud, you should hear the pump priming as the PGM-FI system goes through its self-test, in which case you would have fuel FLOW, but to know if you have PRESSURE, a gauge connected to the service port at the fuel filter is what Honda suggests. We need to know what you don't have. If everything is there, it will be a mixture or timing problem problem...

MFH87CivicSi

I had the alternator tested and it is bad. The main plug cleaned up fine which will save me a lot of time and the lesser wire needs an new O-clip, most this should be in by the weekend along with a new belt.

However I'd like to leave my thoughts on the matter...

The thing that gets me is that it starts every time but sputters out and dies. I can turn it off and on all day so the fuel is there, the spark is there(?), but whatever keeps the vehicle running is not there(?).

Ive read that an alternator sends power through the system and is what keeps a vehicle running once started. If its dead enough it may not start or if and once started may not continue to keep the vehicle running. Also all power that is supplied to and goes throughout your vehicle passes through your alternator and if your alternator is dead, depending on the degree of things, nothing would work or various things may not...And I've also read that if your alternator doesn't hold enough amps or volts, I forget how much and of what, but it requires a certain amount of charge to even get a rig to start - If that alone is not existent, not even a new battery will start a rig.

Now everyone asks, is it getting fuel/spark, without proper means of checking I believe it is. So, what if it is capable of getting both, which I assume it does by its starting power not to mention if I lag blip the gas I can keep it running. And upon start up only instantly I can rev to redline... However, it cannot simply sustain that motion and that's why my thoughts are on the alternator...

JAF Mugen Power

MFH87CivicSi, you speak like a lawyer. Post up your conclusion when this is solved. Good luck.

MFH87CivicSi

rofl - too bad i dont have a bank roll like a lawyer - idk, it could be timing too - wanna buy me a timing light? =p

1grex

My thoughts:
Put simply, the starting & charging circuit is a different circuit than those that keep the car running. All circuits float on the battery. Some cars, once started, will run on the alternator with the battery disconnected, some will not. I have not had a reason to try this experiment with my car. Most cars will run with the alternator disconnected and all cars will run with the alternator connected but not charging. If the battery has enough juice to start the car (by far the largest amp draw on any car) it will have enough juice to run it.

MFH87CivicSi

Guess you are correct, the alternator was dead, replaced, same thing, starts but doesn't stay running.

It starts everytime and it dies out everytime, trying to feed it fuel only starves it worse now than than before. Upon inspection, using same ground point I have power running to the fuse box - from there back, only the fuel pump does not work. Using the same ground, the wire at the driver door, it is a black/green looks fried and it tuns towards the fuse cluster - Again, brake lights and everything else works but fuel pump does not.

I've changed the relay( ? ), maybe I changed something else, it was the main fuel pump relay(?) - small black box that costs about $43 and is an annoying place to get to behind the main fuse panel. What else is there to do, replace fuses randomly, or all those relays?

Long story short, I've got a mechanic coming by to help isolate the problem - I think im at a wall here with skill and tools - I fail! I will post follow up. =\

MFH87CivicSi

Well, it turns out to have been the main fuel pump relay - which can have many names. but it is the relay the power wires for the fuel pump run to. I did re-splice the Black/Green wire, but that wire wasn't going to the pump. Its all about color matching... This relay was my first guess and I did buy it on the 15th, replaced it the same day and since then I've just now found out it was new, but faulty from the store...

So I took the faulty relay back to the store - long story short - car starts and runs*

freydaddy

usually when the relay is bad it wont even start because it doesnt turn the fuel pump on. Glad you got it though.