ok so ive been haveing lots of problems with afterfire, back fire out of the throttle body right?

any how ive done all i can do for now to try to fix it,
spark plugs and wires, dist cap and roater, fuel filter and ive checked and made sure my TPS is set to .45 volts,
(no techsmurf i havent change the fuel filter or checked the timeing yet, thats next

but ive noticed something i never really gave much thought too untill tonight, and thats an extreamly loud vacuum noise comeing from the throttle body, theres a slot on the passenger side thats leads to the IAC and another vacuum hose that i can only guess lead to the crank case. any way my qustion is would this abnormal amount of vacuum cause the afterfire and the care to drop rpm and try to die when i open the throttle at all, and would bad timeing cause this abnormal vacuum

 

That's a different screen name you got there. More than likely, your problem is timing. But you can check for a vaccumn leak fairly easily.

 

I agree on timing.

 

Valve timing. I just had this happen. Does the motor run??? I ran around and around trying to figure out where my problem was, turns out my tesionor broke off and got sucked into the crank gear. Only time you have a motor firing through the intake is going to be either valve timing or REALLY off ignition timing.

 

Valve timing. I just had this happen. Does the motor run??? I ran around and around trying to figure out where my problem was, turns out my tesionor broke off and got sucked into the crank gear. Only time you have a motor firing through the intake is going to be either valve timing or REALLY off ignition timing.
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it runs.. now that ive reset the TPS the right way it idles right at about 750 or so, with no problem, its just when i give it some gas it gives me some problems

whats the diff between valve timeing and ignition timeing and are they adjusted the same way (with the distributor?)

 

That should be .54-.56 volts.

I don't think there's such thing as too much vacuum on a motor this old.. and in the area you're referring to, hearing a vacuum whine as air flows past the IAC when the air duct is disconnected is rather normal.

 

Valve timing would be the stretched timing chain I mentioned to you earlier.. Search for 'timing chain' and you should come up with alot of threads on this.
Uhm..... these motors have tensioners? The '86 and '95 blocks I'm spending a few hours a day with at the moment sure don't.

 

Technically it's a timing chain idler. Mine broke too, back in 2001. The chain had streched so much that it started slapping the idler until the idler broke. There are still pieces of it in my oil pan.

Oh, and to the original poster, I've never heard the term afterfire before. It's usually referred to as a backfire. Also, get a fuel pressure gauge.

 

Anyone have pictures of this? Now I'm a little worried.. there's nothing of the sort in either of these motors.

 

You can kinda see it in this picture:

http://www.angelfire.com/on/freddysp...ck/piston4.jpg


Here's a better one(big pic):

http://www.meisners.net/fiero/Engine...gchain_jpg.htm

You can tell that the idler is old....look at how the rubber is worn off of the left side.

 

OH! Crap. I never even noticed that piece was bolted on... thought it was part of the block casting whoops. Thanks

 

I was having some strange problems with back-fires through the intake on my '87 Camaro SC w/ 2.8L. When the engine was cold (only cold, especially during the winter), it would run really rough and strange, and it would back-fire through the intake at least one time, sometimes twice, once the engine was under a little load (light acceleration in either 1st or 2nd gear). I checked out everything I could, and decided it was something wrong with timing or valves (230,000 mile engine). I finally got around to hooking the laptop up to the ALDL link and checked the sensors out. The Intake Air Temp. (IAT) sensor was reading way to high. It was 31*F outside and the sensor showed 75*F. It seems the mixture was way off until the ECM entered closed loop when the engine warmed up. After I changed that sensor, it hasn't back-fired through the intake again. The sensor was about $10 at the parts store.

 

Here's the pictures of my tensioner, that's what it was called in all the computers at all the parts stores anyway.

https://www.thirdgen.org/techbb2/sho...hreadid=224352

 

well as far as i can tell you guys were right the timeing was off i adjusted it as far counterclock wise as it seemed to go, seemed to set it to about 10*, now my poor baby is bleeding, oil all over the friggin place

what i need to know is, if the hold down bolt to the distributor was not on tight enough would it casue the whole unit to pop out of the oil pan or something along those lines, cause sure enough when i look to see what was going on there was oil all down below the distributor cap, and i have seemingly NO oil pressure, so the best i can figure is that i blew one very important seal or, the shaft has poped out of the oil pan, or how ever that werks
(forgive my ignorance)

Help me please.......

 

ok so i was really scared that i really messed something up she seems to be runnuning really good now and yes it was the timeing thank you to all who posted.....

 

Oil's going to be the fault of your distributor seal. Link to KED85's distributor rebuild is in both the 'Read Me First' and the new proposed readme.

Glad to hear it's finally doing okay. You did set the timing with the EST disconnected, right? (I'm forced to ask this any time someone doesn't say they did due to the number of people who don't)

 

yes i did set the timeing with the EST disconnected, as far as the oil leak goes i figured that out too.... turns out that i managed to not get the hold down bolt in the right place (dont ask me how but it happend) i guess what ever i had the bolt threaded into wasnt the right spot (doing this blind is kinda a pain)
so when i gave her some RPMs the whole unit got pushed out just enough to kill the pressure and let some oil leak out (not even a quart really) so i taped it back into place made sure i had the right hole for the hold down bolt tightned it down nice and snug (hope i can get it back off when i need to) fired her up and she runs great... but your right Tech a distributor rebuild is in her future.......
thank you all again

 

Dude, is your distributor fully seated?? If it isn't, DO NOT RUN THE ENGINE. The dist must be fully seated to drive the oil pump.

EDIT: saw your last post. Looks like you got everything straightened out.

 

The seal is a 1 inch inside diameter o-ring. You can either buy a bag of 5 at pep boys for $1.25 in the metal drawers in their hardware aisle, or, go to a "real" parts store (with concrete floors and greasy computers and ashtrays and bottles of car wax that are sold for $20 for the suckers that come in) and ask them for an o-ring- they'll have a box (usually red) with different sizes in it.

For what it's worth, when I installed the Cloyes true dual roller chain, the instructions said to discard the factory tensioner. The sprockets wouldn't bolt on because the teeth hit the tensioner. So my tensioner is in the basement!