Hello everyone,

I'm new to the forum and have a problem I'm hoping someone has come across before. I have an 89 Civic Si hatch, d16a6 5 speed, that will idle up and down (almost to the point of stalling) when the engine gets warm. It is showing a code 8 (TDC Sensor failure). I have already checked the coolant level, replaced the thermostat, burped the coolant system, checked the timing and put in a brand new distributor. Still shows the code 8, still has the idle problem. ANY help or advice would be greatly appreciated as this will soon be my work vehicle for an HOUR LONG drive to work every day and I hope to have this straightened out before that happens lol.

Thanks in advance,
Hoss

 

Nobody has any ideas at all?

 

My surging idle issue ended up being the IACV, cleaning it did't help and the first one I tried to replace it with was bad also. The third one fixed it. I didn't have a code for mine, but it sounds like it might be a different issue, maybe in the wiring.
Try to clean the IACV and see if that at least fixes the idle, then go after the Code 8.

 

i recently did a compression test and my dizzy was not connected. the cel produced a code 8. later when i finished what i was doing i put the dizz back on, no cel.

1. did you clear the ecu (disconect batt)

2. you sure the new dizz is good

3. check all vac lines going to intake manifold, vap can, map sensor, etc.

my guess is your new dizz is crap

good luck

 

TPS?

 

my d16a6 used to do this. check all of the vacuum lines going to the intake. it turns out that i had a bad hose.

 

Well, checked the TDC sensor ohms reading, it's within spec. I doubt it's the distributor because when I say new, I mean BRAND NEW, not just new to the car lol. I reset the codes by pulling the hazard fuse for a bit, didn't think I needed to disconnect the battery. But wouldn't that just clear the old code? If I fixed the problem it would have the light on but the problem wouldn't come back just because I hadn't disconnected the battery would it? I haven't checked the IACV because I figured the idle issue had to do with the CEL Code 8, and the 2 aren't really related. I did spray every vac hose I could find with starting fluid and the idle never changed so I'm assuming there are no vac leaks.

 

Any suggestions on possible wiring or ECU problems?

 

Disconnected the battery, code is still there along with the problem. I got my hands on ECU pinouts, gonna check to see if the signal is getting from the TDC sensor to the ECU or if there's a problem with the wiring. The idle I think is unrelated to this now. I didn't know idle should be set with the engine warm and the IACV unplugged :/ sooooooooo, we'll see where that gets me

 

where did you get you distributor? I ordered one from ebay once that made my car backfire and just run like crap. tore the dist completely apart and found that the reluctor gear for the tdc sensor was installed on the shaft like 50 degrees off. very very poor quality rebuild

 

It's Richporter brand, brand new. Got it from O'reilly Auto Parts

 

I never buy from o'reilly's everything I have every got there has been cheap crap. Just my .02 and experience with them