70 GT stalling issue

[djenkins63]

This post is for all of you Opel experts as the problem has been asked and we have never found the causing issue.

When I picked up the car and drove it home it would not idle and stalled at every stop and would start again acting like it was flooded. After I got home, I started to find the problem and first rebuilt the 32/36 5a Weber carb and the problem still occurred. I then replaced the fuel pump and still had the problem. I replaced the points, condenser, coil and spark plug wires and still had the problem. I have 3 carb experts look at the carb and the result was the rebuild was correct and we only needed to adjust the carb and time the car correctly. We still had the problem. I now have the Pertronix coil and ingnitor and still have the problem. I have run a compression test on the engine and found that #1 is at 58, #2 in at 90, #3 in at 90 and #4 is 50. I have checked the head gasket, it is good, and the head is torque at 72 ft. lbs. It shouldn’t run! After getting, it warmed up and driving down the road, it has a miss, but runs a 70 mph all day until I stop and it dies!!

I have had many conversations with many of our Opelers and received many ideas and none of them has corrected the problem!!

HELP!

[ungermm]

If it stalls when you apply the brakes, you might want to check the brake booster hose for leakage. If you have the original brake booster hose from the carb to the brake booster, you are likely to have leakage. Check closely where they attach, especially at the carb where it gets pretty hot. One way to check the entire hose is to pull the hose out, plug the end that goes to the carb, and blow air with you mouth into the booster end. If it is leaking you will be able to continue blowing without getting the hose to pressurize.

Jerry

Jerry

[opelnut10]

Originally Posted by djenkins63 This post is for all of you Opel experts as the problem has been asked and we have never found the causing issue. When I picked up the car and drove it home it would not idle and stalled at every stop and would start again acting like it was flooded. After I got home, I started to find the problem and first rebuilt the 32/36 5a Weber carb and the problem still occurred. I then replaced the fuel pump and still had the problem. I replaced the points, condenser, coil and spark plug wires and still had the problem. I have 3 carb experts look at the carb and the result was the rebuild was correct and we only needed to adjust the carb and time the car correctly. We still had the problem. I now have the Pertronix coil and ingnitor and still have the problem. I have run a compression test on the engine and found that #1 is at 58, #2 in at 90, #3 in at 90 and #4 is 50. I have checked the head gasket, it is good, and the head is torque at 72 ft. lbs. It shouldn’t run! After getting, it warmed up and driving down the road, it has a miss, but runs a 70 mph all day until I stop and it dies!! I have had many conversations with many of our Opelers and received many ideas and none of them has corrected the problem!! HELP!

#1 & #4 were low on your compression check. Did you run the checks with the plugs out and dry? Try running the compression check wet (put oil in the plug hole) if it comes up then you have a ring problem (broken of stuck) if it does not come up I would look at a valve problem (stuck or burnt) because you are losing compression somehow in those two cyls. Low compression motors (dish top pistons) at best will run just over 100 if everthing is fresh. Hope you find it soon, looks like you have replaced everything that you can without opening up the motor.

[ungermm]

Wow, I didn't pay attention to the low compression in #1 & #4. That is a concern.

[robinspain]

I had the same problem but with the Solex: Check that there is not a gasket leak around the base of the carb. Do this by spraying "Cold start" if there is a leak the engine will speed up as it sucks it in. It was not a leaking brake servo booster as I thought. Hope this might help.

Cheers

rob

[wrench459]

DJ
Your running on companion cylinders. Its funny how well a four cylinder will run on two cylinders.
Lloyd is dead on with his suggestion of the wet compression test.
I'm no Opel expert by any means but would add a leak down test also.
90 psi even on a smog motor is border line misfire I would like to see 125lbs min. on a '70 flat top with a stock cam.

[djenkins63]

Dry and wet test will be done next week. I have also learned that you can test the cylinders by blowing air into them and watching the filled radiator!

[rrossjr]

Originally Posted by ungermm If it stalls when you apply the brakes, you might want to check the brake booster hose for leakage...

I was thinking brake booster/vacuum leak also, but the strange thing is that the car seems to idle fine for several minutes at a time, but will eventually drop RPMs and stall without applying brake, (or without any external input for that matter) At Thomas's, the car idled strong (warmed up) for quite a while, then just slowed to a stall without anyone in it. After restarting, it ran again for several minutes, then did the same thing. Very odd.
Ron in Indy

[wrench459]

Originally Posted by djenkins63 I have also learned that you can test the cylinders by blowing air into them and watching the filled radiator!

correct
Get each one of the pistons on tdc of the power stroke. One at a time of course.

"hint" remove the dist cap and follow the firing order. After one cylinder test rotate the crank 180 degrees and line up the rotor to the cap.

Apply air pressure to the cylinder....listen for escaping air from the intake, exhaust pipe or valve cover. And of course air bubbles in a full radiator.

[ungermm]

Originally Posted by rrossjr the car seems to idle fine for several minutes at a time, but will eventually drop RPMs and stall without applying brake

Just to make sure I understand, this is your car and a separate issue from Don's?

I think, Ron and I have similar issues. My GT has the same problem. While I wait at a red light, the car will idle fine (around 1150 rpm's) and then gradually drop rpm's (around 600 rpm's before stalling) unless I give it a little gas. I was thinking that this might be a distributer vacuum issue. I need to get the timing light on it an see what happens when the idle drops.

Jerry

[rrossjr]

Originally Posted by ungermm Just to make sure I understand, this is your car and a separate issue from Don's? Jerry

Hey Jerry,
No, I was referring to Don's GT. I had a look at it last Saturday at the Kahlert's. Just thought I would add that info, since it struck me as odd. Most of the time, once a car is running and warmed up, it will continue to run unless something changes.
Cheers,
Ron in Indy

[opelgtmaster3]

have you checked the voltage regulator? i had a proplem like this with my gt. i checked everything and checked again. i ended up changing the regulator just to see if anything changed and it was fine after that.

[djenkins63]

I have had three different (new) alternators, regulators and coils and still have the same problem! Ron was diffently talking about my GT-his was running fine! I can get it to idle at 1200 to 1500 RPM and it still dies! You can smell the gas, so the fuel is not the problem, I think!