Oh yes another CIS quark, Some help plz

MCC31977 · 01-10-2006, 01:11 PM

Ok, i have a 1977 C3 which was running superbly until my last weekend drive to the shore (connecticut-its cold here). Its about a 35 mile (one direction drive) after about 15 miles the car begain to hesitate slightly especially around the 2000-4000 rpm range. I continued my drive, parked the car for 45min, and had a difficult time restarting. (i believe this is simply a malfuctioning fuel pressure accumulator- and is probably a seperate issue but i am including it for completeness) The car restarted but was difficult to drive especially leaving from a stand still. There was significant hesitation and stumbling until i could generate rpms above 3500 to 4000. However on the top end, although no stumbling is noticible there is evident powerloss. The problem seem to become enhanced with subsequent test drives to try to refine my understanding of the problem. I replaced the WUR because it seemed that the hesitation was worse as the temperature increased. I tested the ignition with a spare CD box, i also inspected the wiring harness for damaged frayed wires. With the car idles a bit rough in the driveway, but stumbles when you quickly open the throttle, pops through the muffler, chokes, but then catches up and climbs in rpms and behaves fine. Seams like the car is loading up on fuel (what would cause this?). Upon shut down their is a noticible muffled/lazy pop or two in the exhaust. This behavor is magnified in driving the car due to the load being placed on the motor. To the extent that u need 3000rpms and a featherly touch on the clutch to get the car rolling.

I guess that describes my issue, sorry in advance for the book, and i would appreciate any feed back. I realize that this issues are discussed endlessly, i've been through the treads, but would appreciate a response here.

Thankyou for your help.

Jim Williams · 01-10-2006, 05:18 PM

The popping back through the exhaust is typical of over richness. A guess could be that your WUR is not warming up and leaning out the mixture, if it is indeed a richness problem. Checking the fuel pressures, particularly the control pressure of the WUR, is really the only way to either verify or rule this out.

diy83sc · 01-10-2006, 05:52 PM

I have a similar warm start problem and am almost certain mine is the check valve. How you can test this, but as Jim points out, a full pressure test is in order:

With the ignition in the on position, remove the air box cover, lift and hold the throttle plate for about 5 seconds. Go back an turn the ignition and it should start. This is a symptom of a faulty check valve or accumulator. I don't know where else to point you from there.

Tony

azasadny · azasadny's Garage

Quote:

Originally posted by MCC31977
Ok, i have a 1977 C3 which was running superbly until my last weekend drive to the shore (connecticut-its cold here). Its about a 35 mile (one direction drive) after about 15 miles the car begain to hesitate slightly especially around the 2000-4000 rpm range. I continued my drive, parked the car for 45min, and had a difficult time restarting. (i believe this is simply a malfuctioning fuel pressure accumulator- and is probably a seperate issue but i am including it for completeness) The car restarted but was difficult to drive especially leaving from a stand still. There was significant hesitation and stumbling until i could generate rpms above 3500 to 4000. However on the top end, although no stumbling is noticible there is evident powerloss. The problem seem to become enhanced with subsequent test drives to try to refine my understanding of the problem. I replaced the WUR because it seemed that the hesitation was worse as the temperature increased. I tested the ignition with a spare CD box, i also inspected the wiring harness for damaged frayed wires. With the car idles a bit rough in the driveway, but stumbles when you quickly open the throttle, pops through the muffler, chokes, but then catches up and climbs in rpms and behaves fine. Seams like the car is loading up on fuel (what would cause this?). Upon shut down their is a noticible muffled/lazy pop or two in the exhaust. This behavor is magnified in driving the car due to the load being placed on the motor. To the extent that u need 3000rpms and a featherly touch on the clutch to get the car rolling.

I guess that describes my issue, sorry in advance for the book, and i would appreciate any feed back. I realize that this issues are discussed endlessly, i've been through the treads, but would appreciate a response here.

Thankyou for your help.

My car is doing the exact same thing as described here. What was the outcome? Thanks!

MCC31977 · 08-17-2006, 09:36 AM

After lengthy tinkering as it turns out there was really no problem other than water in the fuel. I had filled up at a small gas station (maybe the end of the tank) and had probably pumped some water into my tank. I put some isopropyl alcohol (aka dry gas) into the tank drove it and put some fresh gas in from my usual station and she has been fine since. Some times the problem is much simpler and less catastrophic then we want to believe.

Anyway that was the deal.

azasadny · azasadny's Garage

Thanks! I wish my problem was that easily corrected!!