NEED HELP! 88 camaro iroc-z misfiring???
 

I have a 1988 camaro iroc-z 5-speed that has a 305 5.0 tpi engine. My car was running nice until after i did a FULL Tune-up and Oil change. The car does not allow me to push the gas pedal to the floor. If I attempt to "floor it" it just hesitates and goes through the rpm's really slow, Also it will back fire and throw out smoke.

It WILL let me gradually push the gas pedal but I can not floor it cause it will just hesitate. At first it was the firing order so I fixed it. It got better but it still does the same. I pulled out the 8 Brand new (just put in)platinum +2 spark plugs and they were already burnt and black. I just bought and put in all 8 new platinum +4 spark plugs. It still acts the same. While I did the tune-up I also took out the MAF sensor screens. and a week before i just put in a new battery, alternator, and fuel pump(didnt replace fuel filter). This is a real problem for me and i need help now. If someone can please help that would be awesome. Thanks.

Your problem may be the MAF screens you removed, but I'm more inclined to think you've got a vacuum leak somewhere. Any chance you knocked off or forgot to reconnect a vacuum line somewhere? That would be the focus of my trouble shooting right now if I were you....

Good Luck!!!


- Vern

Check the vacuum lines going to the evap cannister, mine get knocked off rather easily.

UPDATE!!!
 

Today I got a new MAF sensor and kept the screens this time. The car is running BETTER but still slightly lags and backfires. When I did the fuel pump job we never put in a new fuel filter. On the fuel pump box it said "must put in new fuel filter with this product". I was wondering if this could possibly be the problem? Also it didnt start messing up(with these problems) till after I accidently overflowed my gas tank. Thats all the info that I know of that could possible help you figure out my problem. Please help ASAP. thanks...

Definitely swap out that filter before you do anything else. Cheap and fairly easy to do. Also check the "Check Timing" connector and make sure it's not unplugged. Other than that re-check the vacuum lines. Overflowing the gas tank will not cause this. Something else is wrong.... have you checked the fuel pressure? Might try that before changing the filter, but I'd change it anyway just to be safe since its so cheap.


- Vern

dude, i would check and recheck that firing order and your wires, cuz that sure sounds like mixed up wires to me.

iroc misfiring
 

have you tried re-gapping your plugs ? also, your timing seems to be a tad bit off. the MAF screen probably wont hurt performance.

*UPDATE*
 

I know the firing order is perfect unless im looking at the wrong one. I have the haynes complete mechanic guide for 82-92 camaros and i have the wires at the firing order it says for v8's. If somebody has a different firing order please let me know it nad i will try and do that one. The spark plugs are pre-gapped since there platinum four's, so that cant be it either. Also I just fixed the timing the week before. Im going to try and change the fuel filter today and i will post results after.

Did you unplug the ESC connector when you set the timing? Just checking.....

*update*
 

This morning my car started running like **** as if the timing was off. It was acting very sluggish and i still cant punch the pedal. Later on I replaced the FUEL FILTER and the car ran a little better but still no pedal to the floor. The problem still remains.....

*update*
 

Also when i changed the oil i put in 20w-50(or 40). The car has 100,xxx miles. Could it be the oil causing this problem? I also put a K & N oil filter( the top of it had little rust spots). Could the oil be to thick? thanks fer the help as the problem remains..........

No, that wouldn't case this kind of thing. Has to be something else. What else have you done to the car maintenenace/fixing things wise?

*update*
 

All I did was the full tune-up(spark plugs, wires, distributor cap and rotor, oil change, fuel filter). About a month before the tune-up I put in a new tranny, new fuel pump, new maf sensor, new battery, new alternator. Also when i did teh oil change i put in slick 50. Could my problem possibly be the TP(throttle position) sensor? thats what my freind said popped up when he hooked it up to a computer. Also what do you have to say about my car just running like crap one morning when i drove it after a weekend of good running? It makes a "thump thump thump thump"(car shakes) sound now constantly and even when i just push the gas a small amount there is almost no power as if i suffered a loss in performance. I didnt do no work to this car before this happened, it just was like that when i woke up ad drove off in it in the morning. And it was running pretty good just the day before. thanks fer all your help.......

I would double check your timing make sure you pull the EST wire. Your oil has nothing to do with this problem. Did you get around to checking your fuel pressure? I would think this issue is with timing, crossed wires, vacuum leak, or fuel pressure inconsistent.

check your rotor too if you replace it you may have accidentally broke it when you installed it and check your tps sensor too because i thought my was bad and it wasnt but changed it and it didnt have it set up right and it shot 4 foot flames out the tail pipes and would barely run. and my sure you arent one wire off on your timing, ou could be one to far clockwise or counterclock wise

I would wait till it gets dark and pop the hood, take a look to see if your arcing over anyplace. I know its hard in the dark but try to see if all the plugs are "dark" with no sparks visible. You shouldnt be able to see any Fireworks under the hood. I only tell you this because my car was acting funny too. Turns out my #7 was arcing over to the exhaust...

Lates,

Demo:hail:

*UPDATE-New Problem*
 

Thank you to everyone who has helped me with this problem. I kind of fixed the problem. It was the throttle sensor, i guess it wasnt positioned right so when we moved it the car revved just fine. Im going to adjust it tommarrow to perfection.

But wait, theres a new problem:
Yesterday when I woke up i try'd to start the car and it wouldnt start. There was no power at all, windows dint work, no radio, no power locks so I figured it had something to do with the battery(it's a brand new battery). I checked the connectors and the possitive screw was loose. I put in another screw and had to jump start the car. I left it running for bout 8 minutes then took it around the block a few times. I turend it off and started it right back up about 3 times. Today when I went to go turn on my car the same problem occurred, No power!. The screw is still intact And i cant seem to figure this one out. Could something be draining my battery? I checked and i didnt leave anything on. Please help me with this new problem caue this one is also hard to figure out.

also F.Y.I., the car has a manual fan and amp wires hooked up to the battery. I dont have an amp and the wires are just taped up on the inside of the car. Also the msd box and coil are hooked up to the battery.