I am completely flustered

[DnaProRacing]

This is a continuence to the arrrrrgh thread. My car is still bellowing black smoke and surging. it doesnt do it all the time, just once In a while when I get a little hefty on the throttle. I had injection service done, then got diagnostics done "only tossed o2 error" which I put a new one in, still smoked. was told map sensor, cleaned the old one out and put back in, still does it but not as frequent. so i put a new map sensor in, still does it, again not as frequent. what else could be causing this? pressure tests were done by pep boys as well as my usual mechanic and everything checks out good. block test, head gasket, manifold gaskets, everything checks out good. has new plugs and wires which were tested as well. oil level hasnt changed thru all of this either. I for once am out of ideas, my mechanics are all baffled. btw, new tps, iac, pcv, vacuum hoses, the list goes on. what else could cause black smoke when getting into the throttle??? ideas please? Im so flustered, if i wasnt bald, i'd pull my hair out!!!
oh, it doesnt toss any codes now either...

btw, the name DnaProRacing is from my old online racing days. I ran a team of drivers against other teams. In no way does it mean I am a mechanic. Im learning as I go. This is a new found love "working on my cars". and you guys have taught me a lot...

[maxwedge]

Leaking injector, high fuel pressure, bad fuel pressure regulator, there must be some pending or live codes as a result of this, also a full scan should be done. BTW, I'd suggest posting year and engine here.

[DnaProRacing]

1992 Chevy Lumina Z34 3.4L 6cyl fwd dohc LQ1

[az_emt_911]

Have your catalytic converter checked. Mine is out, and it caused it to surge quite a bit.

[DnaProRacing]

magnaflow converter less than 6 months old. they checked all the exhaust. flowmaster 40 muffs too...

[Will Help]

Definitely excess fuel or retarded spark.

Hows the timing chain. Jumped teeth and excess slop could cause these symtoms. They don't last forever you know. I have replaced them on cars with less than 100,000 before. Teeth worn off and chain stretched usually.

[DnaProRacing]

I was quoted $432 for the timing job. not exactly chump change. Im going to have my usual mechanic check the fuel pressure first. if that checks out, i'll bite the bullet and get the timing done. Its due now anyway. bought the car with 172k, now at 208k. and the guy that owned it before me did absolutely nothing to it "maintainance wise". in fact, he changed the front 3 spark plugs, but he couldnt get to the back 3, so he left it as is. the car didnt even run when I bought it. the oil looked like black water. the air filter was NEVER changed. some people have no brain. they say these lums have to have the timing done every 50k. but i'll have to wait a week for the $$$. I've got about 5k dumped into this car, its not even worth that much. lol. in fact, the blue book is $3100
thanks for all the help guys. hopefully its the fuel pressure. I'll keep ya posted.
update: after i put the new map sensor in, it did it only once a short time after test driving it. hasnt done it since, and I've been driving it pretty hard...

[Will Help]

Sometimes when you replace sensors, the DTC's need to be erased before the computer will come out of compensation mode. Other wise you have to go through about ten cycles of starting and driveing the car to get out of that loop.

[DnaProRacing]

Scratch that. It did it again today, quite a lot. whatever it is, its getting worse...

[4x4 blazerguy]

Originally Posted by DnaProRacing

I was quoted $432 for the timing job. not exactly chump change. Im going to have my usual mechanic check the fuel pressure first. if that checks out, i'll bite the bullet and get the timing done. Its due now anyway. bought the car with 172k, now at 208k. and the guy that owned it before me did absolutely nothing to it "maintainance wise". in fact, he changed the front 3 spark plugs, but he couldnt get to the back 3, so he left it as is. the car didnt even run when I bought it. the oil looked like black water. the air filter was NEVER changed. some people have no brain. they say these lums have to have the timing done every 50k. but i'll have to wait a week for the $$$. I've got about 5k dumped into this car, its not even worth that much. lol. in fact, the blue book is $3100
thanks for all the help guys. hopefully its the fuel pressure. I'll keep ya posted.
update: after i put the new map sensor in, it did it only once a short time after test driving it. hasnt done it since, and I've been driving it pretty hard...

I would think injector hanging ever so often. As for the money in it, I assume it is paid for, so who cares what it is worth if you like it. Better to spend on a used PAID FOR CAR than buy a new one, or even another one.
I got too much in my 97 Blazer 4x4 but it is paid for & we like the truck I will just pay to keep it running.

[Will Help]

Just when you think you can wait a little longer, problems remind you they are still there. Funny that we seem to think they fix themselves somtimes.

[DnaProRacing]

have to wait a week for the cash anyway. but im hoping its just the injector. its the cheapest of the few things left that it "could" be. but it ran so bad today, im wondering if its going to last a week.

[Will Help]

Hope springs eternal. Keep us informed.

[DnaProRacing]

Day 1: no smoke. ran fine all 100 miles. 6 to go. lol

[Will Help]

Could be something broke loose or flushed away!!!