Good evening guys. I'm having issues with my car lately. It's a 97 Elantra GLS Sedan with a 1.8L 4 banger.

I had the water pump go out last week, so I replaced the timing belt, water pump, tensioner, and pulley, and the car is running again. Great! EXCEPT the persistant power hesitation the car experiences when I come to red lights.

When I stop at a light the car idles fine, but when the light turns green and I hit the gas to go, the car starts to come up to power and suddenly hesitates like the engine stumbles for a few seconds, then the power suddenly comes back and the car powers quickly.

I'm afraid it's going to stall out in the middle of the street.

I can't pull the codes because for some reason the computer will not communicate any scanner. (I'm looking into this too).

Idea? Is it the throttle position sensor?

AND YES. THE CAR WAS DOING THIS BEFORE THE TIMING WAS DONE.

 

If your car's ecm is so screwed up that it can't communicate with the ODB II port, then that's a serious problem. Could be related.

As far as hesitation problems like that, sure it could be the TPS, but you're just shooting in the dark.

Could be a fuel pressure problem too.

Could be an ignition problem.

In short, could be just about anything.

 

Thanks for the vote of confidence.... LOL

Any ideas on where to start? Where is the ECU on this car? Is there perhaps a way to test it? Any and all help is appreciated.

 

You need to try and fix the odb II port problem first. You said before that the wires were "Scottish engineered"? Let's assume the ecu actually works, since the car still runs.

 

Ok, so I got the wiring diagrams from HMAservice.com which by the way is a great tool. And the wire colors to the pins at the Data Link Connector match the diagram correctly.

Pin1- Yellow/Blue
Pin2- No pin
Pin3- No pin
Pin4- Black
Pin5- Black
Pin6- No pin
Pin7- Blue/Yellow
Pin8- Yellow (Tampered, someone soldered a piece of blue wire and jammed it in the DLC)
Pin9-Green/Yellow
Pin10- No Pin
Pin11- No Pin
Pin12- Black/Yellow
Pin13- No Pin
Pin14- Yellow/White
Pin15- Blue
Pin16- Red/Yellow

I don't have my scanner here. I'm using a Snap-On Solus Pro. I have checked all the fuses in the panel on the driver side floor. They all work.

Where can we look next?

 

OK! so I got the DLC working and got a p0446 Code - Canister Close Valve Malfunction.

Any ideas if this would cause the stalling issue I was experiencing when taking off from a light?

Also is the CCV a dealer only part?

Also: No transmissions DLC's, Was able to clear the SRS airbag light, as well. Car seemed to run better after the code was cleared.

 

Most excellent! Good job.

P0446 is purge control valve malfunction. This could be your whole problem. If the thing is stuck open, it could cause a vacuum leak. If it's stuck closed, this might cause excessive pressure in the gas tank.

The CCV is a little valve sitting on the canister. On my '99 you just drop down the canister (located in a square black box under the filler hose) and it's hooked up directly to the canister with a hose. You can pull it out and look at it, maybe clean it.

 

What would you recommend using to clean it? Its in front of the driver side tire on mines behind the front bumper

 

Just clean it with spray carb cleaner. The purge solenoid is next to the brake booster under the hood. Your problem is the canister control valve, attached directly to the canister under the filler hose, rear quarter panel.

 

Ok, well I found the canister. It is behind the front bumper on the drivers side, under the headlight. I took off the valve and sprayed it with carb clean, and reassembled, then found the purge valve under the brake booster and repeated the process.

I cleared the ECM of the codes. It was good for about 2 days and then the check engine light came back.

I pulled the code again, and it was the same P0446, and it also was in my "Pending Codes".

Suggestions?