confounding 91 civic start probs - NOT NORMAL PROBS

[josdavlar]

1991 civic DX 1.5 liter DPFI

went out thursday morning to go to work, start car, ran rough for 2 seconds and died. checked oil for fear of no oil situation, had oil. no start since then. crank till the cows come home.

i have spark on all four cylinders. new distributor with all new guts. main relay is functioning and have gas flowing. injectors are within resistance specs but it appears impossible to check for spray since there is no rail. compression seems okay (blew 4 potatoes right out of the head). new fuel filter. all fuses look fine. ECU showed code 17 initially (vehicle speed sensor??) but i can't believe that would prevent startup. ECU still flashes once for its "i'm alive" signal after clearing by pulling hazard fuse for 10 seconds or more.

i've read every forum around and can't find anything that fits my problems. could the ECU be toast?

thanks for any help...

[Bedlam]

Tobi is still out of town..so maybe someone else will have an answer for you. I am just his internet secretary on the other hand...and know nothing about cars. :)

-Bedlam

[powder311]

isn't he at the formula one race?

[Bedlam]

isn't he at the formula one race?

Heh..yeah. :p

-Bedlam

[95GSRB18C]

did you disconnect any of the wiring harness? I had the problem of not having the IACV plugged in. Plugged it in and it started right up.

[josdavlar]

i'll check out the IACV, thanks for the tip.

ignition switch checked out.

[Dynhamik]

my DA had the same problem. check your ECU for an O2 Sensor code but first reset your ecu. just in case you dont know how heres the simple directions.

Reset your ecu/ Pull ecu and hazard fuse.
Change your o2 sensors if needed.

[LV303]

I had that problem in mine before and sometimes when it gets hot and I run into the gas station for gas smokes etc... I come out and the car don't start. I did alot of things to trouble shoot and came across a interesting thread on some tech forum and they said that the 88-91 had cheap main relay's which caused it to start sometimes and not sometimes when it was hot/cold. I went to the boneyard and pulled a couple, waited for the civic to pull the same crap and when it did I changed out the main relay with the ones i got from the bone yard and to my suprise it started right up and I never had any more starting issues... hopefully that helps some... :)

[josdavlar]

yes, i am aware of the main relay issues, and that thing is a mother to find and get out. i've resoldered mine but it didn't matter. the fuel pump is kicking on and i'm getting fuel to the throttle body.

it was suggested that i pull the entire throttle body off the intake to see if the injectors are firing properly (there is no rail and i have spark).

i'm going to try this next.

i don't think the O2 sensor would keep the engine from starting...

[STIBungy]

It doesnt.

i don't think the O2 sensor would keep the engine from starting...

[Dynhamik]

yes, i am aware of the main relay issues, and that thing is a mother to find and get out. i've resoldered mine but it didn't matter. the fuel pump is kicking on and i'm getting fuel to the throttle body.

it was suggested that i pull the entire throttle body off the intake to see if the injectors are firing properly (there is no rail and i have spark).

i'm going to try this next.

i don't think the O2 sensor would keep the engine from starting...

Maybe not but i had the same problem with my integra and it was the O2 but it could always be something else.
Good luck......

[ryanman]

Maybe not but i had the same problem with my integra and it was the O2 but it could always be something else.
Good luck......
The O2 sensor will not do that.

[HONDA GHANDI]

Does it sound normal when you are cranking it or does it sound like it is spinning a bit fast? Sometimes they will flood out and foul the plugs. This problem is usually complicated by a large amount of carbon buildup on the valves. There is a way to fix it but to really know what is going on I would need the car here at the shop for some tests.

[josdavlar]

it does sound a little funny while cranking, perhaps a little fast... but it's hard to know because it usually starts. in other words, i'm not quite familiar with what it should sound like with endless cranking.

i've switched to some dfferent spark plugs, not new but cleaner than the ones that were in there. i haven't cranked it for a day going on two, so we'll see if any gas that may be flooding it clears out. however i thought that fuel injected cars didn't really have a flooding problem like carborated engines.

[HONDA GHANDI]

Civics will flood and cause what you are experiencing. New plugs will not normally solve the problem however. Usually there is soaked cabon on the valves causing a lack of compression which is a key ingredient in a good running car. The potato test is NOT a good way to test it BTW.

[ryanman]

I'm gonna make me a potato gun with this shitbox civic I have sittting here, gonna hook up 4 tubes that'll thread into the head and some sort of one way valve to let the air pressurizeup into a chamber while I crank the car then I can load a potato into it and release the valve and fucking BOOM the potato is gonna fly like 900 yds. Cheap potato gun, LMAO!!!

[HONDA GHANDI]

how come your # doesnt work Ryan? Tried to call you today.

[ryanman]

Cause I'm leaving for Alaska in a couple days, already had it turned off. I'll call you.

[Dynhamik]

All im saying is that i my car would start up for 2 or 3 seconds and then shut off and all i did was change the o2 and it fixed it. But hey im no technician. Cant hurt to try...

[josdavlar]

yeah, i know the potato thing is winging it a bit, but i didn't have a compression guage and it let me know that the pistons weren't f*cked. i now have a legit guage and will test this weekend to make sure. bastard still didn't start after sitting two days - couldn't be flooding i would think after that long.

what do the technicians out there think about the O2 sensor replacement? i just can't see how it would affect anything but emissions control.

[HONDA GHANDI]

It was pure luck that his car was fixed by 02 sensor replacment. They have nothing to do with startup.

[josdavlar]

Civics will flood and cause what you are experiencing. New plugs will not normally solve the problem however. Usually there is soaked cabon on the valves causing a lack of compression which is a key ingredient in a good running car. The potato test is NOT a good way to test it BTW.

what can be done about the soaked carbon? would it mess with compression because the carbon is interfering with the valves properly seating?

[josdavlar]

for whatever it's worth, here's what happened.

the car has been sitting untouched for a couple days. i check the compression with a legit guage. compression wasn't so great, but not so bad that it shouldn't start. i was getting ready to pull off the throttle body as a whole to see if the injectors were indeed squirting. got to the last nut and saw that it was very difficult to get to. frustrated, i loosed the distributor, spun it all the way back (counter clockwise). i got in the car and starting cranking just for the hell of it.

the engine started acting like it wanted to start but didn't. i got out of the car and walked around to the engine and heard a funny electronic type sound. a little buzzing. i bend down to locate it and find the part and unplug it (prolly a bad idea in retrospect but who cares at this point). i get in the car and crank and it starts! it runs but can't hold idle very well. so i run it for a few minutes just to enjoy the sound of the engine.

i look at the LED display. 14 flashes = EACV or Electronic Air Control Valve = the item i unplugged. so i kill the motor and plug it back in. engine starts and now can idle normally.

i ran it for about 15-20 minutes staying within pushing distance from my house. it runs like nothing has ever happened.

so i pulled the hazard fuse to clear the ECU, and am going to let it sit until tonight when i'll try and start it again. then tommorrow morning.

does this make any sense at all??? it's an intake side emissions control device???

[HONDA GHANDI]

sounds like you got lucky.