IDriveHonda

I am having some problems and have recieved no help in other parts of the forum so I figured that I would try here.

Here is my setup:
99 civic cx
Y7 block Y8 vtec head (mini-me)
obd2b to obd1 jumper harness with p28
B16 throttle body with self port matched intake manifold
Fake Jake's intake
ebay $100 header
92-95 EX tranny
*I have not been able to drive my car for 3 weeks and I really need it bad.

Here is my problem:
I drive my car around normally, not getting on it, just easy driving, and it seems to run pretty good. I get out on the highway and go through the gears and in fifth gear it seems kind of doggy when trying to accelerate. If I drive it real easily it seems to remain running fine. If I get on to the highway and floor it, when I get to fifth and get up to about a constant 80mph it barely will accelerate at all and starts to studder a bit, and then when I get off of the highway I barely have enough power to move until I hit 3-3.5K rpms, it boggs pretty bad. I then struggle to get it home and let it sit for awhile and go drive it again and it is fine. I can not drive it this way because it feels like it is going to die on me, but it doesn't, it idles a little rough. I have no check engine lights, the timing is dead on, the compression test checked out good (180-190 across the board,) I thought that I had some bad valves so I purchased another Y8 head and put it on last night with the same results. I am disgusted. I have been searching for hours with no luck and I am desperate. What do you think this could be?

Update:
OK, I am still having problems. I changed out the coil, bypassed the cat, cleaned andchecked the PCV, checked out all of the fuel injectors, disconnected the altC wire that turns the alternator on and off at certain RPM's and it is running a little better. I discovered that I can drive for awhile and it seems like the problem occurs in 5th gear when trying to accelerate around 80mph. It seems to have no top end power on the highway and then when I get off of the highway after it seems that it wont accelerate anymore it has now power below 3K rpms it boggs terribly, but if I turn the car off and back on it will run fine again. I am lost. Does anyone have any idea?

VTECVillain

Is your check engine light (CEL) on? You never mentioned whether it was or not so I thought I'd ask that first. It sounds more like a wiring/sensor issue to me. Possibly the O2 sensor which the symptoms you have described would lead me to believe.

IDriveHonda

During the upgrade process I purchased a 99-00 Si cat so I could use a header and still have a cat. The O2 sensor that I am using was one from my original Y7 manifold that leads me to believe that it is still good. I have gotten it to give a CEL on 2 occasions but I can't get it to come back again and since I did the OBD2b to OBD1 conversion with a 99-00 Si wiring harness and a jumper harness I don't know how to check the CEL. The idle is pretty strange as well. it seems to idle pretty good and then it drops for a while and idles rough for a bit and then idles back up smooth again. It doesn't happen very fast either it might take a minute or 2 for it to change. I have run out of things to try it almost feels slower than before I started.

VTECVillain

Chances are the O2 code is stored and probably still a present problem. Just because you have an OBD1 jumper harness doesn't matter. You should be able to jump the service connector under the dash to check the CEL. By doing this you will be able to see what sensors are giving you problems then troubleshoot them to fix the problems.

IDriveHonda

Thanks for the advice, I will try to find a new O2 sensor and see what happens. Would it be best to get one from the dealer?

VTECVillain

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IDriveHonda &raquo;</TD></TR><TR><TD CLASS="quote">Thanks for the advice, I will try to find a new O2 sensor and see what happens. Would it be best to get one from the dealer?</TD></TR></TABLE>

First you should jump the service connector to see if there are any stored codes. I wouldn't replace the O2 until you troubleshoot and narrow it down to that. The sensor might be completely fine but the wiring bad, there's a few possibilities.

IDriveHonda

OK, I will try that, I would think that the wiring is good because I bought an Si wiring harness so I wouldn't have to worry about it. So you are saying that even though my CEL is not on it will show stored CEL's? I think that I may have unhooked the ecu since then so I will try to get it to generate another CEL. And just to be sure, I can jump the service connector with the OBD1 ecu in and it will still flash the codes in an OBD2b car? Thanks.

IDriveHonda

Another thing that I was thinking of is the cat I got is from a 99-00 Si with the O2 sensor in it. The header I bought has a bung up next to the head in the primaries that I plugged. With the p28 is it OK that I put the O2 in the cat? Also I know on the Y7 manifold there are 2 O2 sensors and they are different part numbers do you think that could be an issue?

IDriveHonda

OK, I have another update. When lining up the cam gear at TDC there are 2 places to line it up, level with the head or lined up with the bottom mark on the belt cover. I had it lined up with the head so I lined it up with the lower mark instead and the idle improved dramatically but I couldn't get the timing right because the dizzy maxed out. So I kept fiddling and took off the cam gear (AEM) to compare it with OEM and it appeared that the teeth lined up different, same number of teeth but the grooves were opposite with the keyway lined up. I timed it this way and drove it and it seemed to have more power but stiff if I floor it in 5th gear at 80mph it throws a cel code 1 which is O2. I know the wiring is good but I am using a O2 from my Y7 manifold but it is moved to the cat do you think this could be my problem? I am using a 99-00 Si cat so the O2 is located behind the collector now instead of in the primaries and I checked some websites and the O2 part numbers are different between ex and dx but I am also running the p28 so I am not sure what I need to try next. Any ideas?

VTECVillain

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IDriveHonda &raquo;</TD></TR><TR><TD CLASS="quote">I timed it this way and drove it and it seemed to have more power but stiff if I floor it in 5th gear at 80mph it throws a cel code 1 which is O2.</TD></TR></TABLE>

This could be due to the car running super rich or lean and fouling the O2. A friend of mine did an MPFI swap and used the wrong injectors which caused the O2 CEL to trip, he replace the O2 sensor 3 times until I ended up figuring out what was causing it. Having your timing out of whack can do the same thing.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">I know the wiring is good but I am using a O2 from my Y7 manifold but it is moved to the cat do you think this could be my problem? </TD></TR></TABLE>

If the wiring has been tested and you know that it's not the problem, then your trouble is somewhere else. You can interchange all Honda/Aucra 4 wire O2's and even aftermarket ones, so that shouldn't be an issue.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">but I am also running the p28 so I am not sure what I need to try next. Any ideas?</TD></TR></TABLE>

Is this a stock P28 or has it been chipped? The reason I ask is some programs and even the people that chip it aren't the greatest.

IDriveHonda

I have a stock P28 ecu. I got the timing set properly with a stock cam gear. My timing light is not adjustable so the red line in the series of 3 on the crank pulley is lined up with the pointers on the timing cover while running and warmed up. I also hooked up the crank sensor just in case because I was told that it wasn't used with a p28, but then I was told the Z6 engines have that built into the distributor and I am using my Y7 distributor. But under these conditions it is still running like I mentioned above and throwing an O2 code. I am really about to give up, it has been a month already.

IDriveHonda

Another Update:
I went to a local import shop (Tokyo Image Motorsport) here that I do a webpage for and I had them try to help me with my problem. We ended up putting a stock Z6 cam gear on because my stock Y7 cam gear didn't have a mark on it to line up with the bottom pointer on the T-belt cover. This revealed that I had the belt off one tooth. We got everything back together and with the distributor maxed out we could only get the timing to 15 degrees, so it is one degree retarded. I went for a test drive with their mechanic and it seemed to do fine but on the way home I threw another code (O2 sensor, code 1) and it started running crappy again. So, the only thing I can figure out is that it is running too rich and loading up, but if I turn the ignition off and back on it runs fine again. Should I try to replace the O2 sensor? Do you think that I should try to put the stock Y8 throttle body back one? And lastly, should I grind out the distributor mounts a bit to get the timing right on? Man, I am really getting tired of this. Sorry to keep bothering everybody.

dogfood

if you think its running rich it might have a hole in the vacum line and the o2 overcomponsates by dumping a ton fuel in. spray throttle body cleaner around your lines in different spots in the engine and if the idle picks up you found your leak. maybe its something simple.

IDriveHonda

Another Update:
I worked on the car again tonight and I grinded out the distributor slots to get the timing better and I also discovered that when my buddy put on the new distributor cap he put the new gasket on with the old one still in there so I took one out because I noticed that the cap wasn't flush on the dizzy. After that I put everything back together and advanced the timing a tad and it seems to run better. I drove for about 30 mins on the highway with no CEL's so keep your fingers crossed. Thanks guys for all the help.