bigfinderman

Sup guys. Gota 97 civic ex. it slung a rod at 197xxx. bought a y7 motor with 80xxx on it. put my head on the y7 block. since installation, it has a rough idle and has progressivley gotten a bad stumble when you accelerate. When the car is cold it does not do this. When it warms up, it stumbles like a "studder box" when under heavy load. If you keep the rpms up, it does not stumble. i have changed the normal stuff, plugs, wires, cap, button, filters. It has gotten to the point now that u have to drive it like you stole it! im getting spiratic codes thrown at different times. i get multiple misfires, knock sensor, 02 sensor heater circuit malfunction, p1298. sometimes it will throw just a couple codes, then sometimes it will throw 7 or 8 codes. need assistance! i dont have much hair left!!

Former User

Which code(s) is consistently thrown?

What brand plugs, wires, cap, and rotor did you install? Are the plugs gapped properly? Have you compression tested the cylinders?

The Y7 block lacks a knock sensor. Did you install the one from the old Y8 block?

Also check whether 7.5A dash fuse 15 is blown.

bigfinderman

Codes p1298, p0325 (knock sensor), and multiple cylinder misfires are consistent. used ngk replacement plugs gapped properly. cant remember the brand on the wires and cap. i havnt done a compression yet. going to today if i have time. i had no idea about the knock sensor. does the y7 have the spot for it? fuse 15 is good.

bigfinderman

also, i messed around with it a little yesterday. while running, i unplugged the wires from the cap one by one to make sure they were all hitting. cylinder 3 wire made no change to engine performance when disconnected. it was sparking, but no engine change.

bigfinderman

additional info. i just read in the faq how to get the cel codes using the ecu jumper. prior to now, i have used a buddys scantool. i checked the codes as stated in the faq. i recet the ecu and went for a drive and checked them again. i am only getting 2 codes now. code 20 (electrical load detector), and 23 (knock sensor). thanks again for any info

bigfinderman

Any ideas fellers??

spedo

I've got a 95 si vtec with JRSC and stage1. ... stumbled like a "studder box" in 2 occasions that I hit it hard from low rev.. once on a wet road. changed my sparkies to NGK Iridium, now my start-ups are relatively smoother with less chatter. This is probably a different problem than yours, but not unless my engine was sputtering during low rev, my mech said could also be caused by worn out clutch (hasn't been changed for the last 11 years). So I'm changing clutch to stage 4.. see if it works.

bigfinderman

i just checked the electrical load detector as described in my repair manual. with the engine idleing, i have 4.5 volts. when i turn the low beams on, i have 4.54. according to the manual, the voltage is suposed to drop when the low beams are turned on. they increased. they state that if the volts do not decrease then you need to replace the eld. what do you guys think?

bigfinderman

Any thoughts guys?? Any help would be much appreciated.

Former User

What are the current symptoms?

Check installed 7.5A dash fuse 15 with a test light as described at the fuses link in my signature. Is there voltage at both top test tabs with the key in ON(II)?

You'll need to install a knock sensor to get rid of the knock sensor code.

bigfinderman

Current symptoms: runs ok when cold. at running temp, stumbles very bad when under a load. almost like a studder box. if you drive it like an indy car, it runs good. idles rough. havnt done a compression test yet. going to today. when you take number 3 plug wire off while running, it makes no change to performance. you can also unplug number 3 injector and makes no siginicant change to engine. also, for the past 2 days, when i first get in the car, my headlights and dash lights flicker for a little while, but eventually stop. im clueless guys

bigfinderman

Anymore ideas or tips guys?? I really dont want to take the civi to the dealership. Thanks

Former User

Does the number 3 plug have bright white spark? Does the number 3 injector pulse gas? Does cylinder 3 have low compression?

bigfinderman

Number 3 seems to be sparking fine. I havnt taken the injector out, just unplugged the electrical to it. I am going to do a compression test here in a few when i get off work. I just dont know if it an electrical problem or fuel problem. got me super puzzled.

Former User

Remove the fuel rail along with the injectors and then crank the engine to see whether all spray/pulse fuel.

bigfinderman

Update. fuel injecters were good. finally did a compression test. shouldve done this first. (side note: when i said cylinder 3 wasnt hitting, i meant cylinder 2). test results: cyl 1- 100psi/ cyl 2- 30psi and was leaking down/ cyl 3- 100psi/ cyl 4-100psi. with that said, why would the other 3 cylinders not have the adequate 130 psi?? car ran like a top prior to rod slingage. i know i should have my a** kicked for not getting the 200,000 mile head reworked before i put it on a 80,000 mile block. i have a couple ideas now as of what the problem is. what do you guys think?? tight valves? bad piston ring? clapped out head all together? thanks in advance

bigfinderman

Thoughts?

bigfinderman

Talk to me big RonJ! What do ya think? Thanks

bigfinderman

another update. pardon my stupidity. when i did the compression test i went plug by plug and didnt take them all out to perform the test. after reading i my manual, i read that i needed to take them all out. so i just did it again the right way. results: cyl 1- 140, cyl 2- 130, cyl 3- 155, cyl 4- 160. compression was holding. so seems to be ok. so now im back to the drawing board. any more thoughts or suggestions would be greatly appreciated. thanks

Former User

Ideally, there shouldn't be more than a 10% difference between cylinder compressions.

bigfinderman

Ok. Any suggestions for possible causes?? Thanks

bigfinderman

Would my knock sensor or ELD CEL codes have anything to do with my problems?

bigfinderman

Checked my ignition timing. Its was sitting at roughly 24* BTDC. Loosened up the dizzy and brought it back to spec. It ran worse. Any ideas??

bigfinderman

Is everyone stumped like me??