Got CEL code 8 TDC sensor. need help - Honda Prelude Forum

1996PreludeVTEC · 06-21-2010, 01:50 AM

im not sure what this code means it just randomly came up. there have been no running problems and i just recently did a full tune. when i reset the light it will stay off for a day or two and it will come back on when im just cruising down the road. what does the top dead center sensor do? And what will it affect being bad

jkoni426 · 06-21-2010, 08:38 AM

download the helms and troubleshoot, pg 11-50 in the '92 manual (pdf pg 239)

SpoonerTuner.com - Free downloadable Honda Acura Factory Service Manuals by HELMS

1996PreludeVTEC · 06-25-2010, 02:01 AM

thanks man. problem resolved

chris89 · 11-28-2010, 10:40 PM

Quote:

Originally Posted by 1996PreludeVTEC

thanks man. problem resolved

So what was the conclusion? What did u find out/ do?

thanks

I drive a 96 vtec as well.

minilogoguy18 · 11-29-2010, 08:05 AM

^He figured it out by downloading the manual and looking at the said pages, you are just as capable of doing the same thing so hop to it.

chris89 · 11-29-2010, 10:41 PM

The reason why i ask is i get code 8 when checking via the connector using a paper clip but when i have it checked via a scan tool, TDC Sensor was not at fault and I only had a p0401 EGR Insufficient Flow code.

jkoni426 · 11-30-2010, 01:40 PM

^then you're doing something wrong. I would fix the egr problem and go from there.

minilogoguy18 · 11-30-2010, 05:41 PM

Yeah, go by what the scanner is telling you, EGR ports are more than likely clogged, fix and reset the ECU and drive the car to see if the CEL comes back.

chris89 · 11-30-2010, 11:19 PM

Actually it was code 80 which is the egr. I feel stupid but then again this is my first time doing this on this car. It can't blink a "0" so 8 slow blinks means a double digital number with a 0 lol. So what's the code 80 mean exactly? EGR insufficient flow i take it? So yeah i removed the manifold 6 months ago and cleaned the manifold and the egr ports for hours with little to no progress with clearing the ports. I used blushes and cleaning utensils and about 10 cans of carb cleaner and various other types of cleaner. I even filled it will carb cleaner and let it sit for a couple hours. Only port number 4 had flow and the 3 others were completely clogged except for #3 it flowed a tiny bit. It was causing my partial throttle acceleration to be jumpy and inconsistent. I decided to block it off, and instantly the engine ran like a champ. I noticed large gains in low end torque etc, as well as 4 more mpg. Anyway, I'm going to make another block off plate or order a new one and drill a hole on the exhaust port spot of the plate to allow exhaust flow into the valve but block intake flow. Hopefully that will take care of it. By the way, it takes 4 full driving cycles for the code to reappear atm.

minilogoguy18 · 12-01-2010, 07:42 AM

Yeah, cleaning the ports on these older cars is pretty hard as they are all welded up and you have to drill them out where as newer cars have removable plates. Shocked that blocking it off didn't make the car run slightly less than perfect as the ECU is tuned to use EGR.

chris89 · 12-01-2010, 10:39 PM

Yeah it actually runs a lot better since the ignition advances in partial throttle to improve the combustion efficiency of the hot exhaust gases entering the combustion chamber, lowering the combustion efficiency. So without the lowering of the combustion efficiency outside gas, and with the ignition advance. It allows the engine to run much more efficiently and produce power more easily. I can't wait until i get this new block off plate design with hole on the exhaust port side of the valve on the plate to allow flow into the valve without allowing the gases to enter the combustion chamber. Therefore hopefully pleasing the ECU. The ecu also has to cause the accommodate for emissions standards with the fuel curve by running richer than ideal to meet standards. That's why running a fully customizable ECU parameters, you can run ideal air to fuel ratio and allow the engine to run slightly more ideal for perfect running conditions without emissions control.