timing light for renix....

I need to get a timing light to check the timing on my 89 4.0
What type of light do I need to buy?

Sorry,I know this is a newb question but I'm a little confused.

T.i.a

Pretty much any inductive pickup timing light will work - but you can't adjust RENIX timing anyhow. Besides, I've checked it a few times, and the results I got didn't make much sense...

Are you having trouble, or just trying to stay on top of things?

5-90

Thanks,5-90 What time is it in CA. now?

I know the timing is non-adjustable.I've been having drive ability issues ever since I've owned it.Untill recently,I started really trying to fix it(been throwing new sensors at it lately).I want to check the timing to make sure it isn't one tooth off.
b.t.w,is it possible for these 4 liters to jump a tooth on the timing sprocket?I think yes but not positive about it.
I've heard about a stretched chain causing timing problems......

If you want to check for chain stretch, get out your 3/4" socket, a breaker bar, and take the distributor cap off. Turn the engine backwards a little (no more than 1/4 turn - you're just taking out any slack,) make a chalk mark on the distributor rim at the rotor tip, and turn the engine forward again. You shouldn't have to turn the crank more than, say, 5* to make the rotor move. (Forward = CW, backward = ACW) More than 5* or so indicates that the chain is stretched, and should be replaced. It's worth noting that some RENIX 4.0 have come from the factory with roller timing chains, and that my 88 with 245K on it has no noticeable stretch.

The ignition timing is, as I said, not adjustable by the owner. However, I've also found that the system is highly adaptable - while running, I turned the distributor 180* each way, and it didn't even stumble at idle. That's why checking idle timing doesn't mean much.

Also, as long as the distributor is properly installed, there's no reason that the distributor gear should jump a tooth. If you like, you can pull it up and check - but I've not seen a lot of wear on these gears. They tend to hold up well.

A stretched chain can cause timing trouble, but it will be more a matter of "wandering timing" than anything else, as the chain slack changes.

5-90