Hello forum. First time poster.

My son drives a 2008 Accord EX-L 4cyl. The other day he got his oil changed, and then next morning it started running rough. It doesn't seem to want to go over 3,000 RPM's and is sluggish. We took it back to Valvoline to see if they did something to cause the issue. They ran a diagnostic and said it was throwing a code for the Camshaft Position Sensor.

I purchased a Denso sensor and replaced it this morning. Car started right up, ran for about 5 seconds, then it died. Now it won't start at all. I put the old part back in, and I still can't get it to start. Won't even fire.

I know nothing about these cars, so I'm coming here in hopes someone can recommend a few things to try before I take it to a shop.

Appreciate it!

 

So I got my hands on a Code Reader, and all I get is a LINK ERROR. I also tried to connect with a Wifi enabled scanner to my iPhone, also won't connect. I connected them both to my Jeep and each device reads just fine, so the devices work.

So, no code :-(

Looks like it's going to the shop on Tuesday.

 

Does the engine turn over just won't start, or it does nothing when you turn the key?

 

Battery is fine, car turns over but won’t fire. It went to the shop this morning, I’ll keep everyone posted.

 

So, here is my update, with some repeat of my initial post.

It all started with what seemed like a basic oil change done at Valvoline, as usual. The next morning, he started his car and it was running low on power and “misfiring” (his words). I met him back at Valvoline for them to take a look since they were the last to touch it and they ran a diagnostic which reported back a bad Camshaft Position Sensor. As he was leaving Valvoline, the battery died. They jumped him so he could go on his way. I had him park it at my house rather than drive it around. Next day, it wouldn’t start because the battery was dead, again. I jumped it and took it around the block to experience what he was experiencing, and it definitely lacked power. The RPMs also “bounced”at 3,000 as if it was limited. I ordered a new OEM sensor, and as I went to remove what I thought was the sensor, I realized I was taking off the wrong part. It was a sensor located under the battery on the front of the motor, or maybe the transmission. After I had it unbolted, I realized it was wrong because the connector was different, so I put the bolt back in and plugged it back on. I finally found the correct sensor and replaced it. The car started right up so I started to back out of my driveway to take it on a test drive. I didn’t get 2 feet before the car just died. At that point, it would turn over, but wasn’t firing at all. I decided to put the original sensor back in, and it acted the same, turned over but not fire. I’m the mean time, I put a new battery in it and had it towed to the shop I purchased it from.

After the shop diagnosed the car, it was determined that the timing belt skipped a few teeth causing it to run poorly. I approved the installation of a new timing chain (car has 142,000 miles, 4cyl). Once completed, the starting issue returned, but was intermittent. Mechanic could replicate it, and it was random. He initially thought it might be the ignition switch because the car was not recognizing the key (no green key light), but it would randomly start. He also noticed that if he messed with the shifter, it would start. A Honda forum suggested it was the neutral safety switch, but I would assume that would prevent the car from over completely.

As I drove the car home tonight, I noticed that the speedometer wasn’t working, and then check engine light came on, and the car seemed to limit me at 4k RPM. I called the mechanic and he seems to think it’s related to whatever electrical issue is causing the car to intermittently start. I’m going to drive to for the next couple of days to see if I notice any issues, but it all seems a strange, and my mechanic is booked for the next couple of weeks, so I just took the car back for now.

I write all of this in hopes that there is some one out there that can potentially help direct me before I sink anymore money into the car.
Thanks!

 

I agree the neutral-safety switch would prevent the starter from running. Sounds like the starter DOES run, so that's not your issue.

Probably not a complete answer, but since the timing chain skipped, I'd try measuring the compression. Or verify that the shop already did that when they changed the chain.

Speedometer not working and CEL has been triggered? Can you connect your scanner & read the codes now after the shop worked on it? Try a parts-store see if they can read codes. There's something like 4 different data-protocols, and some of the small inexpensive readers can't read them all. I had a cheap reader from harbor freight that would read our 2001 Saab but it couldn't read our 2003 Accord or the newer Saabs.

 

Ok, so I got home and plugged in my reader. It will NOT read when the car is off, but reads when the car is running. Only code it gives me is the P0720 - Speed Output Sensor. If that is truly bad, that would explain the Speedo, but not the other issues.

 

Maybe something there... I don't know enough specifically about 2008.

Certain earlier years of Accord, I think the PCM applied a lower rev-limiter in the case of no-signal from the VSS. The idea was if the car wasn't actually moving, the engine was apparently being revved in neutral, and shouldn't be allowed to exceed some lower RPM limit.

Like I said, I don't really know whether 2008 has this "feature". Even if it does, it might explain the rev-limit behavior, but not the lack-of-power.

 

It almost sounds like a plug on the intake tube was left unplugged. My son ran into that with his 08 Civic Si, and the engine wouldn't rev above 3,000 rpms. He was plugging in the reverse light switch that had been unplugged since before he bought the car. Plugged the plug back in and cleared the codes and it was good to go.