Car running like crap...
Thread Starter
Safety Car
Joined: Aug 2000
Posts: 3,943
Likes: 44
From: Florham Park NJ Port Credit Ontario
Car running like crap...
2 weeks ago it was running absolutely perfect....in fact, its never ran better.
Now today, its like a different car. Hesitates, chugs, misses, exhaust pops....
At idle, when I rev the engine, it seems fine. In gear while cruising at 25mph, sounds like its missing. It kinda sputters. Upon heavy acceleration it misses big time.
I made sure all the plug wires were tight and swapped out the fuel filter. No change.
Could I have gotten some bad gas?
What else would cause this?
Now today, its like a different car. Hesitates, chugs, misses, exhaust pops....
At idle, when I rev the engine, it seems fine. In gear while cruising at 25mph, sounds like its missing. It kinda sputters. Upon heavy acceleration it misses big time.
I made sure all the plug wires were tight and swapped out the fuel filter. No change.
Could I have gotten some bad gas?
What else would cause this?
Melting Slicks
Joined: Aug 2003
Posts: 2,135
Likes: 2
From: Dayton Oh
A vacuum is a possibility however if you've not done ANYTHING then a bad load of fuel could be the problem. If you've changed something then start looking there. Otherwise before starting to chase a vac problem, I'd dump some dry-gas into the tank and run it awhile. If this doesn't help then maybe start looking for a hose that's fallen off. What ever it is, I bet it is going to be something simple.
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
and the last fill up was .....after the heavy rains???? has the car been inyour control could some have screwed with you at a parking lot.......my bet is bad gas
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Team Owner
Joined: Jul 1999
Posts: 26,545
Likes: 46
From: Huntersville NC
maybe lars spilled beer in it? 
last time my vette took a sudden nosedive in performance one of my plug wires had fallen off... but you checked those already. I bet it's a hose off the carb. After all, the carb was off recently. agree that it should be something simple... hmmmm (thinking..............)
I just reread your post.... make sure distributor is snug (also recheck timing) could have been not tightened down properly and turned. Car would have run perfectly as you noted for a while, then a slightly loose hold down might have allowed the distributor to turn.
last time my vette took a sudden nosedive in performance one of my plug wires had fallen off... but you checked those already. I bet it's a hose off the carb. After all, the carb was off recently. agree that it should be something simple... hmmmm (thinking..............)
I just reread your post.... make sure distributor is snug (also recheck timing) could have been not tightened down properly and turned. Car would have run perfectly as you noted for a while, then a slightly loose hold down might have allowed the distributor to turn.
Enthusiast
Joined: Dec 2004
Posts: 263
Likes: 12
From: AL
Stu,
A longshot, but check to see if the battery fully charged. With an MSD if the battery / charging system drops below 9-10 volts it will exhibit symptoms like that before it stops running altogether.
A longshot, but check to see if the battery fully charged. With an MSD if the battery / charging system drops below 9-10 volts it will exhibit symptoms like that before it stops running altogether.
Melting Slicks
Joined: Dec 2003
Posts: 2,487
Likes: 1
From: Sydney
Originally Posted by jlaw68
if its been 2 or 3 months ago, then that gas has gone bad. its was probaby fine when you filled up but over time it will go bad just from sitting. gas now just doesnt stay fresh like it used to.
my guess...BAD GAS. 
My car had similar symptons to what you described,..it came on the boat from the USA so the gas was in the tank for 3 months or so. ...
anyway, I so didn't think BAD Gas would be causing what you described.......but I added some fresh gas and BAM! car was much much better.
Racer
Joined: Dec 2003
Posts: 304
Likes: 0
From: Pasadena Maryland
I had the same problem last year. On the way to Ocean City it was running just fine. Then it started to run like crap. Especially on acceleration. I turned around and came home. Went crazy trying to find the problem. Went as far as replacing the Distributor with a new Mallory HEI. Still ran bad. My son suggested I change the spark plugs. and Knock on wood. It's been running great ever since. Who would have thought that the plugs went bad. I have had the same gas in my collector cars for months at a time. Just put a good stabilizer and some dry gas in it for the winter.
Thread Starter
Safety Car
Joined: Aug 2000
Posts: 3,943
Likes: 44
From: Florham Park NJ Port Credit Ontario
Thanks for the input guys,
I checked the vac lines....they were all in place. I will re-check everything and report back.
I'm stumped...could I have a bad accell pump in the carb?
I checked the vac lines....they were all in place. I will re-check everything and report back.
I'm stumped...could I have a bad accell pump in the carb?
Racer
Joined: Nov 2004
Posts: 485
Likes: 1
From: Oakville ON
Originally Posted by Stewart's74
2 weeks ago it was running absolutely perfect....in fact, its never ran better.
Now today, its like a different car. Hesitates, chugs, misses, exhaust pops....
At idle, when I rev the engine, it seems fine. In gear while cruising at 25mph, sounds like its missing. It kinda sputters. Upon heavy acceleration it misses big time.
I made sure all the plug wires were tight and swapped out the fuel filter. No change.
Could I have gotten some bad gas?
What else would cause this?
Now today, its like a different car. Hesitates, chugs, misses, exhaust pops....
At idle, when I rev the engine, it seems fine. In gear while cruising at 25mph, sounds like its missing. It kinda sputters. Upon heavy acceleration it misses big time.
I made sure all the plug wires were tight and swapped out the fuel filter. No change.
Could I have gotten some bad gas?
What else would cause this?
Do you have complete control over the car? A friend of mine had the same simptoms and almost went nuts trying to find the cause (he is very knowledgeable) and finally found water in his tank. He leaves his car in the driveway and he figures a kid poured the water in because there was so much of it (about a quart I think). He found it by siphoning off the bottom of the tank. As you rev up under load the flow of gas picks up enough to sweep in the water.
Melting Slicks
Joined: Jul 2003
Posts: 2,166
Likes: 0
From: wilton ct.
bad running engine
it does sound like the dist. has moved,or possibly bad gas....check with lars,maybe your check bounced and he recalled the tune-up,.....seriously keep us posted on what you found out. the info might be helpful to a lot of us.... 
Thread Starter
Safety Car
Joined: Aug 2000
Posts: 3,943
Likes: 44
From: Florham Park NJ Port Credit Ontario
I'm stumped.
The Dist does not appear to have moved, all vac lines are in place, plug wires are all secure.
Could it be the following:
1) Bad gas (still)
2) debris in carb jet
3) bad accel pump
4) coil related
As I said earlier, it seems to idle fine. The miss/skip/bog, whatever you want to call it, happened once while cruising at 25mph, upon heavy throttle, the car sputters badly and wont accelerate like it should.
Incidently, I filled it up w/93 octane as it was just below half full when the problems started. The problem persisted.
Any more ideas?
The Dist does not appear to have moved, all vac lines are in place, plug wires are all secure.
Could it be the following:
1) Bad gas (still)
2) debris in carb jet
3) bad accel pump
4) coil related
As I said earlier, it seems to idle fine. The miss/skip/bog, whatever you want to call it, happened once while cruising at 25mph, upon heavy throttle, the car sputters badly and wont accelerate like it should.
Incidently, I filled it up w/93 octane as it was just below half full when the problems started. The problem persisted.
Any more ideas?
