Smoking when acceleration

saturn
sl

#1

Last time I drove my car, a 1992 Saturn SL2 with 105K mi., on the Mass. Pike, my acceleration started to feel rough. When I looked back, billows of smoke were coming out the tailpipe. When I backed off the accelerator, it was OK. But whenever I really pushed it to accelerate, it would just spew smoke, which it turns out is gasoline, not oil.

OK, guys, my check engine light has been on intermittently as well for quite some time.

When the shop read the fault codes, it came up with an EGR valve and computer faults.

Does this make any sense?

What do you think it could be?


#2

If that much gasoline vapor is coming out of the exhaust, the first thing to check for is a leaking fuel pressure regulator.

Tester


#3

It seems that when the engine was above 3000rpm was when it would smoke.
maybe this isn’t gas??
But it was a bluish smoke, not black.
would a failed EGR valve or computer do it too?
the repair shop wants to replace the computer.
isn’t a computer replacement (junk yard) expensive?
Should I even think about that, ro look for a different shop??


#4

If you want to limit your repair costs, you will make the necessary repairs right away. By causing excess unburned gasoline to flow through the catalytic converter, you are slowly but surely destroying that very expensive component.

I would suggest that you follow Tester’s suggestion, and have the fuel pressure regulator checked, as it does sound like it is malfunctioning and needs to be replaced. In addition the EGR may need to be cleaned or replaced. Do you really want to have to replace the catalytic converter also?


#5

That’s what I figured when it happened, only more damage could be done, so I brought it to the nearest shop I could… and there it sits.
When I talk to the mechanic. I’ll bring up the fuel pressure regulator.
So, you think an EGR valve could do it, too?
Ok… makes me feel a bit better about this mechanic, plus its one of the computer codes.
but he wants to replace the computer?!


#6

The “shop” doesn’t know what to do? Nice!
Check the fuel pressure at 2000 rpm for three minuets. The fuel pressure should be within specifications. This check includes checking the action of the fuel pressure regulator. Check the operation of the EGR system. Check the output of the oxygen sensor.
The EGR operation tends to lean an engine; but, it won’t cause a rich running engine.


#7

Black smoke usually indicates too much gas in the fuel/air mixture and the motor is running much too rich. Bluish smoke generally indicates worn rings or oil leaking past the valve stems in the cylinder.

Your CEL and computer codes should get you on track to buring the correct fuel/air mixture. If the bluish smoke remains your motor is telling you it is getting tired. Are you adding oil between oil changes? If so, you are moving into a motor overhaul with new rings, and valve work. Pretty expensive so you may just live with burning a bit of oil and a puff of blue smoke on start up and hard acceleration.


#8

I wish it were just a puff of smoke… it smokes pretty steady once I get above about 3000 rpm until I drop below it or take my foot off the accelerator.
My computer codes only show the EGR and computer fault though, no other engine faults.
Yep, I am adding oil between changes as well.
My car goes nowhere (avg, 5-7K mi/yr) so the oil changes are pretty far apart.
ugh… I hope it is not an overhaul…


#9

"It seems that when the engine was above 3000rpm was when it would smoke.
maybe this isn’t gas??

Okay, now I’m really confused.
First you told us definitively that, “it would just spew smoke, which it turns out is gasoline, not oil”. When you make absolute statements like that, you tend to send everyone on a wild goose chase, and this helps nobody–most of all YOU.

Do you know whether the smoke is from excess gasoline, or from oil, or are you just throwing random ideas at us? If, in fact, the smoke is from oil, then none of our suggestions so far are on target, with the exception of Uncle Turbo’s comments.


#10

sorry 'bout that…
don’t mean to run you guys around at all…
It was the mechanic who said that it was gas, but I thought that the smoke was white/blue, so I’m not sure which it is because the symptom I saw could be an oil leak.
I’ll wait until the mechanic gets back to me to find out more…


#11

I thought you had a mechanic who knows how to do compression checks and vacuum gauge checks. A lot of oil burning will foul the oxygen sensors and the catalytic converter.
Is it going to remain a mystery as to what the “EGR and computer fault” codes are? You can give us the raw codes, such as P0420. We have our own decoder rings.


#12

If this is an automatic there’s one other possibility, a ruptured vacuum modulator for the tranny. Tranny fluid being drawn into the cylinders will produce clouds of white smoke on acceleration. A shop can check the modulator line for signs of tranny fluid.

Have you checked your tranny fluid lately?