4 replies to this topic

[Lumpia]

Well, I got my rex running finally, the problem is, it won't idle unless it is totally warmed up. I have tried adjusting the idle, it adjusts when it's hot, but has no effect on the cold idle. The choke is working properly, as I have tested that. I had a vaccum leak, that is now fixed.

When I first start it, it will go up to fast idle for about 2-3 seconds then try to drop back down to around 750 and just stall out. As the car starts to warm up, it will start to surge to try and maintain idle, then eventually die.

The spark plugs in it are really old, and I know I need to replace them, but I'm not sure if that's what's causing my problem. Could it just be old gas?

The car sat for 7+ years while I was overseas. I put fresh gas in it, but I'm thinking that maybe there is some old residue in the system that could be causing the issue?

The car will run ok when it's cold if I keep it running with the gas pedal. It bogs a little bit when you try to accelerate if it's cold. Once it warms up, it runs like a dream.

Any ideas about what might be causing this would be greatly appreciated.

[84classicDX]

Sounds like a vacuum leak that seals itself when things warm up. Do the brake and parts cleaner test (spray around the carb) when it's cold and idling to see if you can locate the leak. Since your car does not want to idle, have a friend assist you in this process.

[Lumpia]

Sounds like a vacuum leak that seals itself when things warm up. Do the brake and parts cleaner test (spray around the carb) when it's cold and idling to see if you can locate the leak. Since your car does not want to idle, have a friend assist you in this process.

Alright, will have to try that, could it just be the carb needs to be rebuilt?

[Greg Gauper]

Sounds like the auto choke is not working correctly. When they get old they sometimes kickoff too early. Or you are missing a vacuum line.

When you start the car cold it should fast idle on the auto choke at around 1500-2000 for about 30-60 seconds, then drop down to a slightly slower idle of around 1000rpm until fully warmed up, at which time it should idle normally at around 700-800rpm.

Are you sure you are following the correct cold start procedure? You need to fully depress the gas pedal to the floor once and then release to set the choke, then try to start the car with your foot off the gas pedal. If it starts and dies, the choke probably kicked off too early. Press the gas pedal to the floor once to reset and try again.

If it still acts up, start looking at Tom's online service manual. Here's a link to get you started:
http://www.redpepper...1a/aak.png.html

The factory manual is very detailed and should point you in the right direction. You will probably need to get your hands on a hand operated vacuum pump, it will help in troubleshooting. You can get one at most auto parts stores or buy one on-line.
They aren't expensive. A vacuum pump for bleeding brakes will also work.

[Lumpia]

Sounds like the auto choke is not working correctly. When they get old they sometimes kickoff too early. Or you are missing a vacuum line.

When you start the car cold it should fast idle on the auto choke at around 1500-2000 for about 30-60 seconds, then drop down to a slightly slower idle of around 1000rpm until fully warmed up, at which time it should idle normally at around 700-800rpm.

Are you sure you are following the correct cold start procedure? You need to fully depress the gas pedal to the floor once and then release to set the choke, then try to start the car with your foot off the gas pedal. If it starts and dies, the choke probably kicked off too early. Press the gas pedal to the floor once to reset and try again.

If it still acts up, start looking at Tom's online service manual. Here's a link to get you started:
http://www.redpepper...1a/aak.png.html

The factory manual is very detailed and should point you in the right direction. You will probably need to get your hands on a hand operated vacuum pump, it will help in troubleshooting. You can get one at most auto parts stores or buy one on-line.
They aren't expensive. A vacuum pump for bleeding brakes will also work.

I have checked the choke on the car with the air filter off, it stays closed, and is opening slowly as it should. I am not missing any vacuum lines that I can tell, however one may be cracked.

I am following the proper cold start procedure. Push the gas all the way in to engage the choke, don't don't the gas. It will kick up to fast idle (around 2k) and then try to kick back down, and that is when it stalls out.

I'll have to check out the manual, I have a couple different manuals, and they don't have anything to say about the matter, other then possible vacuum leak.

I have a brake bleeder pump, so will have to try that out. I have a bunch of silicone vacuum line laying around as well, and may just start replacing all the lines.

I have other fish to fry at the moment though, I changed the spark plugs this morning, car ran fine, but when to do some errands around town, and car started running hot. I also bought a timing light to see if it might be a timing issue. For the time being, I think i'm going to put the old plugs back in, they were not in bad shape at all.