Hey everyone. I need some big help. I have a 2005 Civic EX 1.7L with an intake and headers. The problems come up every once in a while, namely when the car goes over a pot hole hard or a bad bump, especially the front passenger wheel. The engine just shuts off after. It will start right up, but then idles really low and poorly. It has been doing this for quite a while now, and I checked the codes. It said crankshaft position sensor. I had it looked at, and it turns out I had a cracked water pump that was leaking on to it, which had wrecked it.

Yesterday, I took it in to get the timing belt, water pump, and crank position sensor changed. When driving it home, it seemed fine and I was very happy. This morning though, I started it cold and the problems were there. I turned it over, it started, then shut off. I can keep it on if I give it a little bit of gas at the start, but then it idles really low, running really really rough, and running rich. As I drove it to work, every time I put the clutch in to change gears, the engine speed would drop really quickly, making every shift difficult. At lunch I drove it around a little, and every time I would put the clutch in to come to a stop, it would just shut off. It would start back up, but again I had to give it gas to keep it on.

All of these problems were there before the timing belt, water pump, and crankshaft position sensor were changed.

Other things I've done with the car to try and fix this problem over the past three months:

• Changed all the spark plugs
• Changed two of the ignition coils
• Changed the throttle body with IAC and throttle position sensor
• Changed the air filter

No matter which mechanic I ask, even the dealership, they aren't sure what could be causing this problem. I need some major help. Any ideas accepted please! If there are any clarifying questions, let me know.

 

I would start by checking the PGM-FI Main Relay... Main Relay Fix, Troubleshooting (Honda, Acura) and how to solder they are a common, intermittent^, problem on Honda and Acura

Running rich, I would check the ECT sensor or its wiring to the ECU. 94

 

Ok. After the timing belt and crankshaft position sensor change, I reset the ECU and drove around for a while. When I checked the codes, I had an upstream O2 sensor no signal code, and a MAF sensor high code. I'm assuming the O2 is out of whack due to the air flow into the engine. I bought a MAF cleaner, and then came home to find out this engine uses a MAP sensor not a MAF sensor.

Is there any chance this could be an issue with the fuel pump? More often than not, it feels like the engine is starving for fuel. If I'm at a stop and I tap the gas pedal, I hear the hiss through the ram intake but it takes a little longer for the engine to actually rev up. As long as I have my foot on the gas it keeps running, sputtering around 2-3k RPM. Once I lift off the gas and put in the clutch, the engine will fall low and either die or almost die. Is the fuel pump a viable problem source?

Also, is it possible to fix the main relay issue with a new relay? I don't have soldering equipment here unfortunately.

 

Update. I changed main relay and put in a new one, and did the idle re-learn. Car ran beautifully for an entire day. Worked well most of today, and then on my way back from work, the power dropped and the problems started all over again. Next suggestion? It feel like the engine is starving for fuel, and it also sounds like one of the cylinders isn't firing quite right along with the others.

 

You need to check fuel pressure, the fuel pump may be on it's way out, mine took 4 mo before I replaced it, it was very intermittent but got progressively worse.

A fuel pressure gauge is not that expensive with fitting that allows you to permanently mount it above fuel filter, handy to have as a quick look will confirm or eliminate the fuel problem at any time. 94

 

Hey fcm. How do you check fuel pressure?

 

Just thought I'd give a quick update. The last time things got bad, after I'd changed the relay, it turned out that the harness hadn't been tightened quite well and the wires were touching the wall of the car body. I fixed that, and it worked pretty well. Last night on a road trip, the problems started up again, and it seems like the relay may have gotten a bit loose due to vibrations as I was driving. I simply pushed the relay to the harness a little, and started it up, and it was beautiful. I wonder if there's a better way of keeping it secured. The harness is a thin metal bracket, so that's not absorbing any vibrations.

 

De-pin the terminal in the PGM-FI Main Relay plug, [if that is the relay your talking about] give the terminal a little squeeze with some plyers, [not too much] so they will be a little tighter when plugged into the relay.
It sounds like the lock clip on the plug is missing, if it was there the plug could not come free/get loose, if it is missing/broken hit up your local bone yard, PicknPull and get a new plug and pin your wiring into it. 94