A few weeks ago I had posted about a random check engine light that I was getting after driving about 20 miles, after the car was restarted the cel went away. The code it threw was o2 sensor. I finally broke down and took it to Honda, the cel was caused by 4 seperate things and it also needed a new ingnition coil. For those who had similar problems the 4 things Honda said were causing the CEL were: o2 sensor, dizzy cap and rotor, injector o rings bad and bad fuel pressure regulator. With these things replaced the cel went away.
So next round of problems. The main relay, fuel pump and fuel filter have been changed there are new wires, plugs and dizzy cap/rotor/ignition coil. Unfortunately after driving some the car will start slightly bucking, almost like losing power for split second. It also does it in the idle after awhile. The car does not die, but does have that little buck. If I floor it and bring it through the gears it goes perfectly fine, but in normal driving and idle , especially right after shifting the little buck/hesitation proliferates. There is no CEL associated with this, and obviously honda did not pick it up in their diagnostic. Tomorrow I am cleaning and replacing all the stock grounds. The only things I can think that it might be at this point are the map or tps. The iacv has been cleaned, although I dont see it as applicable to this problem as my idle is generally good. Any ideas or suggestions before I have to resort back to Honda would be greatly appreciated. Once everything is straight and running like it should be I will post a thread with every problem I have had and every solution to those problems from start to finish.

 

I'm having the same symptoms in my 89 Si. Does your RPM gauge needle kinda jump when it bucks and hesitate? I haven't changed anything out but according to the service manual, it should be the fuel pressure regulator or O2 sensor. Only other thing is maybe ECU is bad.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by clubef9 &raquo;</TD></TR><TR><TD CLASS="quote">I'm having the same symptoms in my 89 Si. Does your RPM gauge needle kinda jump when it bucks and hesitate? I haven't changed anything out but according to the service manual, it should be the fuel pressure regulator or O2 sensor. Only other thing is maybe ECU is bad. </TD></TR></TABLE>
If the needle jumps when it does it, it is barely. I wish it were the fuel pressure regulator and o2 sensor because both have been replaced with oem from honda.

 

is there anyway we could tell if the distributor rotor f*cked up? like burnt sign or something? sorry...i'm quite a noob at this and i don't fix my car by myself.

i've experienced the symptom where the engine dies after driving for about 8 minutes (or even just let it idle for around the same time). the ecu throws code #15, but there was no CEL. i couldn't get the engine restarted straight away, need about a minute or so. Then it will start like nothing happened.

i have replaced the ignition coil, but it didn't solve the problem.

my mechanic suggested that i change the main relay. i did that, got main relay (used) off 5th gen model (grey colour). the car went fine for about 2 weeks plus, but eventually the similar problem happened again.

actually what i did before all this happened was swapping the automatic cams out of my B16A (it was an automatic B16, but I'm running with manual tranny) with cams off EG9 B16A manual cams. I also changed the sparkplugs to a set of NGK Iridium, got em from some friend.

 

As for the MAP and TPS there was another thread about a slight hesitation in lower rpm's a couple of days ago and I responded to it mentioning the MAP and TPS.

I too have been experiencing this and I finally got fed-up with it and just ordered them both. So I will be replacing them probably today and hope to have results tomorrow.

I haven't done the FPR so if it doesn't go away I will do that too. I will let you all know my results.

PS: I'm going to do them one at a time so I can find the root cause.

EDITED: Well this is being put off til the weekend to see where I can find parts cheaper. I can't believe over 3 bills for a MAP sensor. Looks like I'm off to the junk yard.


Modified by thesmogman at 10:54 AM 9/12/2007

 

i picked up a map at the junkyard today for 10 bucks... i also picked up a spare ecu just to put it in and make sure that its not some fluke and the ecu is bad.. the ecu if fine unfortunately haha. I put in the junkyard map and it made my idle less rough and some other improvements completely unrelated to the sputtering.
iv driven it more so the sputtering has become more specific. at idle it will hesitate slightly to where the rpm needle will drop about 1mm and then recover.. eventually it got worse and worse untill now it is at the point to where it almost dies but doesnt. it starts fine everytime and it drives fine (aside from the hesitation) it has only acted like it would almost die at idle, when driving it sputters but not bad enough that it seems like it is going to die. im at a total loss, if i havnt figured it out by friday i will take it to the dealer.

 

Is this the thermostat grounding?





It looks pretty nasty. Could it be the cause why I am getting random engine shut off syndrome?

What should I do if I want to re-ground that thing?

 

I would definately clean that up. Disconnect the battery and disconnect those and sand to bare metal everything so it makes good contact. Even the bolt. I would apply some dielectric grease all over it. Clean the battery terminals too along with any other grounds you can find like the tranny one and the chassis by the battery.

I installed a ground wire kit from Ebay and my idle is for the most part steady. You will have a slight drop when the Alt kicks in always.

 

dont use dielectric grease that does not conduct electricity. use anti seize that does conduct electricity