Ok so how this started was I woke up one morning went out to start the car and all of a sudden I had a crank no start problem so I checked the usual things spark and whatnot and I narrowed the problem down to my fuel pump relay. So I replaced the fuel relay and I also took out the egr valve (I think that's what it's called) because I heard that these could get clogged and it would cause it to get stuck. The egr had a bunch of carbon build up that I gentle scrapped away and replaced but I noticed that when I first removed the two 12mm bolts that there was no gasket of any kind??? So I replaced the egr valve as I found it idk if it's suppose to have a gasket or not and like I said I replaced the fuel relay behind the glove box. And wouldn't you know the car started up but now something is happening that wasn't happening before the car is reving itself all the way up to about 3200 rpms and back down to 900rpms(this is about where it was idleing before without going up and down) then back up and back down back up and back down etc. I really don't have any idea what's going on now. Could I have put in the fuel relay wrong? Like upside down or something if possible? Is it the egr valve and it's suppose to have a gasket? And that's causing this problem? I don't even know where to start now if anyone can help me out with at least a starting point to where I should be looking for the problem I would be grestful. O also the mantaince req. Light is on now as well and before the crank no start it wasn't on if that has anything to do with it and it's throwing no codes as well.

 

Could be a vacuum leak. EGR valve gets a gasket. EGR ports get clogged too with carbon.

 

Ok ya that's what i tried to clean up the port with the "bolt" that goes up and down. I cleaned up a bunch of carbon build up in and around it because it was pretty thick but not causing any kind of problem function wise it seemed. So should I go get a gasket for the egr valve then I don't think it even had one when I lifted off the engine. Also I will try looking at the vacuum lines to see if that's the problem. I'll look up the vacuum lines diagram or whatever for the car shouldn't be that hard to find on google right,?

 

So update I checked all the vacuum lines for any leaks, etc and found nothing everything looks fine from what I can tell. I just ordered a new egr valve with gasket just to do it being the one on there now was pretty black underneath and it not having a gasket with it in the first place had me worried. Idk if that's the problem but I don't think so(it would be nice) as I haven't got it in the mail yet. Does anyone else have any other suggestions as to what could be causing this problem I'm stuck and really need this car. I actually use it for work so I'm kinda screwed right now. I don't think anyone answered when I asked(I know it might be the dumbest question ever but just want to make sure) can you install the main relay(fuel one behind the glove box) upside down or wrong in anyway as my uncle actually took them out cause I had to do something for my son and I didn't get to see the way they came out so when I installed them I just lightly pushed it in without forcing it and I figured I was good. Cause like I said before this crank no start the night before I was driving the car and when I got home and turned it off it was working great. So I was a surprised when I went out the next morning and the car was just cranking and cranking but it was sounding like it was about to start but then wouldn't. Any other help or suggestions I would greatly appreciate. O and there is still no codes the car is throwing but my maintenance soon light is on and it has never come on just the check engine light for a vtec malfunction

 

Bump anyone I have today to figure this out as I have work tomorrow and need the car to drive and I have no more "sick" days left so im desperate

 

If you had no idle issues prior to this most recent one, I would bet that once you get the gasket for the EGR valve, your idle issue will be resolved. Other possible issues, depending on the exact engine you have could be the IAC (Idle Air Control) on the TB (Throttle Body). It should have to coolant lines running to it and is located on the passenger side of the throttle body if I remember correctly. The EGR valve gaskets are made pretty durable and have an almost metal like appearance to them. I have two that I pulled from the junk yard off of other engines that look like they would still work without an issue. Have you had any over heating issues recently or any other major work done to the car? I rebuilt the engine on a 2005 Civic EX with the D17A2 engine after it had over heated due to a serious oil leak from VTEC solenoid(Variable Valve Timing Solenoid). After I started it up for the first time after completely rebuilding it(started instantly) it then begun to idle erratically. I believe this is referred to as hunting idle, but don't quote me on that as it's been some time. My problem ended up being the injector base plenum/manifold on the rear of the engine. When the engine had over heated, the injector base plenum/manifold warped ever so slightly. Took me a while to figure it out. Just search around on the forums for surging idle/hunting idle and you will find a ton of possible causes and also solution. I do agree that it is related to a "vacuum" leak somewhere. Mine just happened to be something you would not think of as a vacuum leak.

Also if your fuel pump relay went bad, I am assuming it is the one behind the glove box. There are two relays there. One is a four pin, the other is a five pin. With the car running feel them with your hands to see if they are unusually hot. If so you may have a short somewhere in the car that is causing excessive current to be drawn on that circuit. There are A LOT of things that are connected to those relays depending on you engine. There are some know wiring issues with the 7th gen civics. Like the one in the drivers door harness. Where the rubber boot connects door to frame, wires have been know to break or the insulation bare, which can cause intermittent shorts.

**P.S.:** I am not an expert and do not claim to be. I only claim to have spent thousands of hours on my girlfriends 7th gen civic. All of the information you seek is somewhere on this forum or the internet and I was able to fix every problem with her car, except for the electrical ones, which can be daunting and make you want to tear your hair out. Mostly due to having to try and squeeze yourself into awkward positions trying to access the places where you need to troubleshoot.

 

There are two relays related to the Fuel Injection System which includes the fuel pump. One is a four pin relay and the other is a five pin relay. They can not be installed backwards due to the way the pins are shaped, but the relays could be installed in the wrong slot. For example if the blue relay #1 and orange/brown relay #2 were removed it is possible that relay #2 was plugged into #1 slot and #1 into #2 slot. I believe my civic has 4 relays behind the glove box, maybe five, and the two fuel injection related relays were the closest to the radio.There are so many different configurations for the relay layouts on the 7th gens, due to Hybrids, EX/DX, hatch backs, etc.

***********Simple answer though if only Relay #1 was removed it can only be reinstalled one direction due to the asymmetrical design of the pins on the relay***********************