Carb "Hiccup"

[todd reid]

Question for the collective braintrust of SAOCA:

I was returning from a car show Saturday. It was hot as heck- somewhere between 95 & 100. I was accelerating uphill in the passing lane on the Interstate in 4th gear doing approx 75mph when I suddenly lost power. I thought I had lost my electric fuel pump. In the brief time it took to pull over into the right lane, the power was back. In the approx 10 miles to get home, I tried to recreate the problem and was successful only once, again when accelerating briskly in 4th gear.

My troubleshooting plan of attack is as follows:

1. Try to recreate the problem in more normal weather (85-90) to see if the excessive heat was possibly an issue.

2. Check electrical connections to fuel pump

3. Change fuel filters. Cut open old ones looking for dreaded black paint flakes.

4. Examine and possibly replace rubber fuel lines. (electric pump is in spare tire well, so most fuel lines should be under pressure, not suction).

5. Examine recent Brake Servo installation for possible vacuum leak.

Question: Is there anything in the carb itself I should be looking for (possibly a vacuum leak that only shows up when vacuum is high??)

Engine is 2800V6 w/ 2bbl motorcraft carb in stock tune (but all polution crap & vacuum lines removed). Car has been on the road approx 15 years & 15K miles since total engine rebuild without a sign ot this "hiccup" before.

Thanks in advance to all for your thoughts!

 

[Jim E]

Could be the fuel tanks, or an igntion problem. My car did very near the same thing just the other day and I have not figured out what is wrong. Driving along and it was like the key got turned off, rolled to a stop hit the key and it fired right up.

 

[todd reid]

What we have learned in the last 12 hours:
1. "Hiccup" is the first sign that your Facet electric fuel pump is on the way out.

2. Murphy's law still applies: Pump died on the interstate. So many trucks roaring by I couldn't even hear my engine running. 5 more miles and I would have been on a nice quiet country road.

3. Carrying a spare electric fuel pump is a good thing! (I was back on the road in 10 minutes).

I still plan to change out the fuel filters, and check the old ones for signs of paint chips.

 

[MikeH]

Could be the fuel tanks, or an igntion problem. My car did very near the same thing just the other day and I have not figured out what is wrong. Driving along and it was like the key got turned off, rolled to a stop hit the key and it fired right up.

I had a similar problem with a Datsun. It was the fuel filter. I'd drive along fine then the engine would die. Pull off the road and it would start right up. Drove a bit more and it died again then started right up again. Luckily I had a clear fuel filter on it. It looked fine until I shook it. Shaking it stirred up an almost talc looking material in the filter. So when driving the "talc" would get sucked up and block the filter. The engine would die and the "talc" would settle out to the bottom, until I started the engine again.

 

[Bill Blue]

Could be the fuel tanks, or an igntion problem. My car did very near the same thing just the other day and I have not figured out what is wrong. Driving along and it was like the key got turned off, rolled to a stop hit the key and it fired right up.

Jim, this the the symptom I experienced on two different cars running the Dura Spark ignition system. In each case, the box was at fault.

Bill

 

[Jim E]

I am not using the Ford box but a Crane HI6 which does not mean the Crane is not failing, which has crossed my mind. On the fuel front I have a spin on canister type filter, maybe I should look at that too. Was hoping it is a minor electrical connection type fault or a bad ignition switch. Have not really done any trouble shooting on this other than in my head, the car is sitting under cover resting.