L0krin

I have a 95 DX with the 1.5L non-vtec and a 5-speed, with a 4-2-1 stainless header.

Since I got the car, it would misfire and stutter when I started it up after it sat for about 30 min, when this "studder" happened I would just floor it while accelerating for a couple seconds, and it would go away and I wouldn't have a problem until I let it set. The car would idle extremely low, but it would never stall so I didn't really think much of that. I used to get code 43 regularly, but after I changed the fuel filter it rarely comes on now.

I changed the wires, cap, and rotor about 3000 miles ago, and the plugs about 600 miles ago, and I also started running midgrade gas (for better mileage) about 600 miles ago, and the car ran as usual until a couple days ago.

Recently the misfire started to happen all the time and as soon as the engine gets to about 2500 Rpm it will stutter and shake so bad that it wont even hardly accelerate, and I can't get it to rev out above 4000 rpm at all.
When I sit still I can rev the car up no problem but if i hold it at a higher rpm it will start to stutter in neutral also.

What should I try first to replace? I am on a tight budget and I need my car to be reliable. I was thinking the fuel pump or the ignition coil would be a good place to start. But I also read online that the O2 sensor can cause code 43. However my CEL is NOT on right now.

turbo_coupe_EJ1

coil would be a good place to start but if that doesnt fix it i would run a timing light on it

98EKCoupe

IAC valves are also known on those engines, I would remove it and check the spring for excessive carbon build up or even a broken spring

L0krin

I cleaned the contacts in the cap and rotor some, and ordered a new coil. Hopefully thats the problem, will post results. When I put the new coil in, I am going to clean my throttle body sensors as well.

L0krin

After putting the new coil in it runs fine again.

L0krin

Well my misfire/stutter is back...

I tried unplugging spark plug wires, one at a time. cyl 2&4 make a big difference when unplugged, its less obvious with 1 and 3 but you can defiantly tell when they are unplugged.

I tested the resistance on the fuel injectors, in order 1-4 the resistances were: 12.3 12.1 12.2 12.3 I tried unplugging the injectors one at a time, and the car's idle changed exactly the same with each injector.

Next I tested the fuel pressure at idle, it was 41 psi with the pressure regulator disconnected, and about 32-33 psi with it connected again, this seems a little low, but it is still within spec, although it almost seems like it misfires worse during acceleration when I have less than a little over 1/4 tank. This makes me think fuel pump...since I have already changed the fuel filter, however that doesn't really explain the idle misfire.

Sorry about the long post, just wanted to explain as much as possible. I am going out to put the timing light on it right now. Will post results when I come back in, any other suggestions, or things that I should test? Open to any suggestions.

gearbox

iTrader: (95)

what kind of spark plugs and wires?

L0krin

I checked the timing, after I jumped the wire under the dash, the timing was at 9 degrees before TDC, I moved the distributor so that it was at 16 degrees before TDC, and then took the jumper wire out, disconnected my battery for 15 min to reset the ecu.
After starting the car it idled smoother but still had a defiant misfire, took it for a drive and 3k in 3rd gear, it started misfiring and misfired at any rpm in the gears after that.

Took the car back home and put my old spark plugs back in (bosh platinum plus) and after that I still have the misfire at idle, but runs fine at any speed in any gear.

My "new" plugs that I had in there were bosh platinum +4 plugs (these are what i just took out). I have Bosh wires as well.

I guess my car doesn't like the expensive plugs???
Has anyone else had experience with these plugs?
My "old" plugs aren't really bad but have a lot of miles on them...what plugs would you all recommend?

P.S.: The car is still misfiring at idle...but at least I got the annoying stutter during acceleration taken care of

gearbox

iTrader: (95)

bosch plugs and wires are garbage (for hondas). i would recommend ngk or denso plugs and ngk wires only. if you're poor, get the NGK v-power copper plugs for $2 each. if you're rich, go with some denso iridiums. both will perform the same.

L0krin

Alright I am going to go to the parts store tomorrow and pick up some NGK vPower spark plugs, I will see if that helps my misfire. I am going to have to wait until I get paid again if I have to replace my wires though.

Will post results.

gearbox

iTrader: (95)

make sure you check the gap, almost all honda are 0.044 and you should change the wires too. its prolly the plugs tho causing the misfire. ive seen non ngk parts cause serious engine problems before esp the cheaper wires.

L0krin

Looks like I might have to get a set of ngk wires.

I bought ngk vpower copper plugs, and I gapped them before putting them in, the car doesnt seem to run any better or worse in the higher rpms, but there is still a misfire when idling and when I am slowing down if I give it a little gas to keep it from slowing down quite so fast i can notice a little bit of a stutter during deceleration.

Got a vacuum gauge while I was at the parts store too, was thinking about getting an air filter as well...right now I have a K&N aftermarket air cleaner, it is looking pretty beat up and almost like it got crushed a little bit before I got the car. Do you think this air cleaner could be causing some of my problems?

gearbox

iTrader: (95)

its possible, K&N filters do not work very well (only 92% filtration instead of oem 99%) and the oil they use can get sucked in the engine and intake and clog up certain parts.