Hello guys,

Yesterday was my first run with my camaro this year. I drove it about 40 miles yesterday without any problem. Today, after about 15 miles of driving, i was accelerating steady and engine suddenly began to sputter, cutting In and Out while driving during about 15 seconds. It seemed to lack of gas but the tank was almost full. However, the engine didnt stalled and suddenly ran ok, so i went to home. Started the engine not completely cold then go to gas station at 10 miles. No problem. 1 mile after, the engine began sputter inch in and out like before for a few seconds but not so bad (not Stalling), so i drove 15 miles and the car began to sputter in and out, then stalled completely. I started it, drove 100 feet and stalled again. No start at all and no explosion while cranking. After 5 min, it started fine than stalled after a second, but when i tried again, nothing. Towing Towed me at home and i tried to start after an hour... nothing at all. I removed the fuel filter hose, changed fuel filter éven it seemed ok. I cranked the engine with hose of and fuel pump pressure was ok. After reconnecting hose the car started like new. I drove down the streets and all was ok. I added a can of alcohol in the case There was water in gas. I insulated fuel hoses in case it was a vapor Lock. Drove 15 miles and it started to sputter in and out, but was idling fine. Gone back in the road for 10 miles and all were ok. Tomorrow, I have 150 miles to drive so I fear to have problems. I want to repair it before.

I have the car since 1 year. Last year the engine had a full gasket and rings refresh. The mechanical pump is new. Carburetor was rebuild, cleaned and adjusted. The spark plugs, wires, cap and rotor, ignition coil, ignition module was changed last year too. BUT the pickup coil was not replaced. After this repairs, I drove it daily for 8000 miles without any problem. But now, the season isn’t beginning good!

Do you have ideas of things that could cause sputtering when warm like this. And why it’s intermittent? It seems to Sputter differently than misfires, because its smoother than Misfires when it bogs down.

No fuel regulator.
the routing of the fuel delivery hose is : tank strainer, hose, aftermarket filter to protect the pump, hose, mechanical fuel pump, hose, and fuel filter in carburetor.

I plan to drive the car until it stalls completely and carry my tools with me to check what is going wrong but I need suggestions and know how to check parts.

Hello,
now, the car runs fine excepted it sputtered a bit on the last run. I was going up a 6% Hill and just at the top it sputtered, but not stalled. It done the problem 5 times. The first time, it was a few seconds after rolling on a bump. The second time, I was departing from the gas station, accelerating. Third time, I was departing from a rest area and it stalled. On the fourth incident, i accelerated after restarting. Then after I put a bottle of alcohol for cars before last run, but the tank was full already, so I don’t know if it blended correctly. And the last run, 5th time, going up that 6% Hill.


Do do you think one bottle of Kleen Flo alcohol is Enough.

When i will retry, the car will have sat for about 14 hours. The water density is 1 per m3, weight more than alcohol which is 0.792 per m3, weight more than gas (680-790 per m3). So maybe it will mix correctly at the next bump or sharp Turn?

The car sat for 8 months with 2/3 tank, outside with temperatures of sometimes -20F.

If if you have other ideas it would be nice Too. I want to bring tools in case the problem appears again to find the trouble. Now the car is ok so it’s hard to find.

Does mechanical fuel pump could fail randomly? (Its new of last year)
Pickup coil in Distributor?
Carb? (Rebuild by me with ac Delco kit, but I put several thousand miles without problem since)
Vapor lock? (It’s possible the gas station had 5-10% ethanol. I put gas one time (full tank) at least 40 Miles before the first incident and full the tank again as described, so 2 times.

I will put another can Of alcohol and tank full with 91 octane. I will bring my tools and run it until it stalls. Pray for me... I need some advices to make tests alone when engine hot...
i plan to check the fuel cap is venting correctly, then check if there is gas in carb when I accelerate after the engine stalled. After that, I will make tests with pickup coil and coil ohm resistance, but it seems a pain of the *** to check that on the side of the road . I think the most important is to make my tests when the car doesn’t start. Hope it was just water and the gas line will helps.

OK, i will replace the two fuel filters. But after that, what should I test if the problem is still there?

When I opened the old fuel filter on carb, I have seen a little rubber debris of 1/8 inch inside. Is it possible it’s a fuel pump debris or more hose debris?

I cutted it and all was ok excepted a little rubber debris, not enough to clog the filter.

I drove 40 miles on the hills and it finally sputtered than stalled. It was possible to not stall if I let off the gas, but it gets worse every minute, i ended up slow down from 60 mph to 20 mph then it stalled definitely. It was not able to start. I unplugged the hose from tank to carburetor and it was completely dry. I put this hose on a jug than cranked 10 seconds... dry again. I sucked the hose between the pump and tank with my mouth and was able to suck gas easily. I put snow from the side of the road to cool the pump, put the hose in a jug and cranked. Not a lot of gas but it pumped gas. I plugged the hose to carb and it started fine. I will let the engine coil completely, go back home and replace the pump...

I sucked the hose between the pump and the tank. When I done the test, the pump pumped absolutely nothing. When cold, the pump squirts but not as much as you say.

I think it’s a bit of hose... I have seen bubbles from the outside of the pump. I think the pump gets air from outside when hot because the seal between the aluminium and metal expands and come loose. The problem is worse when hot but not seems to be the diaphragm. I will change the oil today in prevention.