backfire and running ruff

[BBAINUTAH]

History: I bought this 1990 4runner with a known start problem. The report was that it would run fine, then after you shut it off and attempted to start it later, it would crank but not start. I bought it cheap and am trying to fix it. As I drove it home, it died after a mile.
Long story short. I finally discovered that one of the pick ups in the distributor was loose, bent and partially broken. I replaced it (distributor) and it starts up and runs, but it has a popping noise from the exhaust (small backfire) at low rpms, but idles at 1000. At 1500 rmps and up it runs very smooth. It has no power. I did attempt to set the timing, but I don't know how to lower the idle to properly set the timing. Its a v6 manual with approx 140k miles. CRAP!! I just remembered that the engine was replaced with a 1993 engine several years ago, does this make a difference?
Any help will be much appreciated...I'm the ultimate newbe

 

[GonOvr]

Make sure you didn't stab the distributor 180 degrees off. Yes it will still run, and cause the symptoms you are stating. When you replace the distributor, you want to make sure the no.1 cylinder is at TDC compression not TDC exhaust.

 

[BBAINUTAH]

when I installed the distributor I held my finger over the #1 cyl. spark plug hole while the engine was cranked. I felt the compression "puff", then used a wrench to get (fine adjust) the mark on the pully to match up with the 0 on the engine plate. Aligned the marks on the dist. as per my Toyota Mechanic. The rotor lined up with the #1cyl. plug/contact on the dist. cap.
Could this still have been incorrect?
Another note:
I also replaced the MAF sensor at thehttp://www.tamemymind.com/blog/images2007/smiley-bangheadonwall-yellow.gif advice of the mech. at the wrecking yard.
Before I figured out it was a bad dist.
After all these repairs were done, I found out that this engine is from a 1993 4runner, and of course mine is a 1990. Toyota says these distributors don't match up. Could this be the whole problem?

 

[BBAINUTAH]

When I said mine is a 1990, I ment the 4runner is and all of the repairs to engine have been done based on a 1990 engine. The engine is a 1993.

 

[GonOvr]

Toyota says these distributors don't match up.

Did the '93 engine come with it's distributor? Maybe you should ask how complete the '93 engine was when replaced.

FSM Timing Instructions.
First make sure you did it this way.
Make sure your firing order is correct.

If all of this is good your problem may be else where.

 

[BBAINUTAH]

The prev owner doesn't know any more than the engine was replaced with a 93. Inside of the 1990 dist. looks quite a bit different than the 93. I'll retrace my steps (on the timing) and if all else fails, I have access to a 1995 with a blow engine, I may take the dist. off of it and give it a try. According to Toyota, 1992 - 1996 are the same. Thanks Big Time for your help!

 

[GonOvr]

You're welcome! Hopefully you get it running right.

 

[BBAINUTAH]

Well as embarrassing as this is to say, I had the #2 and #4 plug wires crossed:bash: In my defense, thats how the chilton book showed it, still pretty bad!
IT RUNS PERFECT NOW!!arty:
Thanks again for your help GonOvr!

 

[GonOvr]

Good deal man! Glad everything worked out.