Hi guys,

I am still having all sorts of trouble, and i am not convinced i have my timing right...i am trying to decide if i have a bad opti or if my timing is wrong.

I have 2 symptoms
1. no power at low rpms...and i mean it just crawls off the line
2. high rpm backfiring - at about 5k rpm

I bought my opti from another forum member, it had like 30k miles on it and was from a '95. I retrofitted the car to accept it, which involved pulling the timing chain off and replacing the upper gear. I talked to him, it was off the car for 3 weeks, and he only replaced it as preventitave maintenance. Could an opti go bad that fast?

Is there some way to put a timing light on my car and see what the timing is? i already pulled the timing cover off once to re-check the timing, and it seems perfect, but the car runs like crap. :smash:

i have a new opti on the way, but if the one i already have in there is ok i would just keep it until i can swap cams so i don't have to hack part of the back of the new opti off to fit with the stock '94 cam.

how have peoples cars responded with timing off a tooth? with a bad opti?

what do you guys think?

thanks!!
:cheers:

 

You can't check the timing. Basically the opti either works or it won't. When my car had the cam off a tooth it ran like a turd. It didn't want to idle properly when it was warm. In general the car just behaved badly. I thought it felt OK but it wasn't great. Sure enough I couldn't even manage a 13 at the track.

If you are a tooth off in the other direction it might act differently. Timing wise the opti is timed off the cam, so if your cam is advanced your spark will be advanced, and if the cam is retarded your spark will be retarded. I know it sucks to think about but it seems to be happening to a lot of people these days, myself included.

I guess lining up those two little dots is just too hard for us to comprehend.

 

how do you know if it's lined up right? i already pulled it all back apart once, pulled the timing chain, and put it back on, as far as i can tell it looks perfect...wouldn't you be able to tell? i put a straight edge on it and it looked great. My car seems to idle fine, and rev fine with no load, under load at low rpms it can barely get out of its own way, and at high rpms it backfires...does that sound like an advanced/retarded timing situation?

 

how did it idle? mine seems to idle ok...my tach reads almost 1k at idle, but it doesn't sound fast, and has always read that...

 

contrary to what everyone says you can assembly the opti in the wrong position. When the drive gear goes into the cam and the opti it should be a loose fit. It will go together if the splines are not lined up properly, so beware of how the fit up is. Your best bet to be sure you have the gear lined up is to first install the drive gear into the cam shaft end (use a small mirror to see the flat spot) then with the cap off install the opti by turning the rotor until you feel it line up with adjacent flat on the drive gear. Hope this helps.

 

i have an opti from a '95, so there is no shaft, it connects to a pin on the edge of the cam... :)

 

In my case it was blatently out of line. I would like to kick myself for not seeing it. If you've lined it up with a straight edge you should be alright. Did you turn it over a few times by hand and make sure everything still lines up?

Sometimes you can turn it over once or twice and suddenly it just doesn't look like it's lined up the way you had it.

My car would idle OK, after it figured it out, but when I first fired it up it would try to surge for a little while and would want to die. After a few minutes the computer would learn how to keep it alive, but it would act up again as soon as I would start it up. Strange thing was that it ran better if the car sat overnight than if it was warm. If I fired it up warm it had a LOT of trouble.

I don't doubt you man. It may well be something else, especially if you've torn it apart again to look. What about the injectors? Fuel filter? You don't get any SES lights?

 

The majority of comments you received are correct. My last Opti Spark lasted less than 6500 miles. Yes, you can check the timing but it is a real pain. I ran a mark on my fly wheel when the engine was down and checked timing from below. Turned out my DFI was 6 degrees off.

 

585 rwhp :crazy:

what do you by the engine was down? at TDC or what? how do you know where to make the mark?


:cheers:

 

what did it do when it went?

 

i turned it by hand a few times and it looked right on, i would think a tooth off would be somewhat obvious...
well, hmmm...mine idles great, just like it used to...
no SES light, and in fact, no codes at all...it is just weak and backfiring...what would a weak coil do? fuel filter is a year old, it fires up instantly when i start it so injectors should be ok right?

 

Sounds like you need to make friends with somebody who has a snap on scanner or some other data logging software. That stuff can tell you all kinds of good info.

 

hmmm...anyone in the detroit area have a scanner? :jester

 

Just a stupid question... Are you sure you have no plug wires swapped? Have you started the engine in total darkness to look for spark arcing anywhere???

 

yes...one of the first things i checked
no, i might try that tonight though...

 

how do you test the fuel pressure? is there some way to watch it while you are driving?

 

You can go to any parts store and buy a handheld fuel pressure gauge. Tape it to your windsheild and go. Or you can spend about $180 and buy a nice one from autometer that you can install permanantly like I've got.