Is there a problem with my warmup regulator?

SpeedracerIndy · 08-11-2004, 10:03 AM

The car has always run very rough from a cold start. If I were to floor it right after I start it, it boggs down and doesn't want to rev up quickly. Once the engine is warm, within about 2 minutes, the problem quickly and completly goes away. It runs very well and very strong once warmed up. Once it is very warm, say after 20 minutes of hard driving, it will buck if the engine is lugged. For example, if the engine is very warm, and I were to put it in third gear at 25 mph, and then floor it, it would buck pretty badly. After searching around and monitoring many threads, I came across one where it was suggested to unplug the top vacuum line from the warm up regulator, plug the line going to the throttle body, and leave the line into the warmup regulator open to the atmosphere. Well, this seems to have cured both of my problems. What does this mean? Is there something wrong with my warmup regulator, or is it just a coincidence, and will one or both problems reappear?

I had the engine out recently and the air box and all vacuum lines are in good condition, so I know there are no leaks causing this. Also, the mechanical AND vacuum advance on the dizzy are working. There is no vacuum retard on this dizzy since it is an 81 RoW motor. Plugs and wires are fresh. The only thing I am not 100% sure of is weather the mixture is set correctly, but so far I don't suspect this to be a problem since it doesn't run too cold or too hot, and other than at startup doesn't smell rich.

SpeedracerIndy · 08-12-2004, 01:49 PM

Uhhh, did I forget to say please to the pelican experts or what? No one can give me any advice here?

Paulporsche · 08-12-2004, 02:10 PM

I think you were running a little lean at startup and rich when warm. Since you did some searches, you probably have noticed that the control pressures could be off, which means the WUR would be out of adjustment. There are gauges you can use to check this. Likewise your mixture can be checked. Is your timing OK? Have you checked your O2 sensor?

Does your idle fluctuate at all? Do you get any popoff valve popping other than at cold start?

SpeedracerIndy · 08-12-2004, 03:30 PM

The idle does fluctuate. When cold it stays right at 850-900. Once it warms up it climb to as high as 1200. It doesn't always climb though. Sometimes as I'm sitting at a stop light it will slowly climb up to 1200, then after about 10 minutes of driving it will be normal again. This is pretty common. What does this mean?

Paulporsche · 08-15-2004, 07:04 AM

If you try a search, you will find lots of possiblities for this. You may have a vacuum leak. Your cold mixture may be too lean, and maybe a PO or a mech has raised your warm idle speed in compensation.

Try detaching and plugging the lead off the top of the decel valve and check for air leaks. Also make sure your dist is turning and returning normally. Also, if you can, try to check your warm and cold control pressures with a fuel pressure gauge.

Before you get or try the gauge, you can try the decel valve thing and try richening your mixture slightly. You may have to raise your idle speed slightly after.

Good luck and let us know what happens.

azasadny · azasadny's Garage

I'm thinking vacuum leak....

SpeedracerIndy · 08-15-2004, 09:09 PM

I am almost positive it isn't a vacuum leak. At any rate I'm sidk of dicking with this damn thing, and I don't have the time. It's going to Farmer auto sometime this week. He said he would get the thing running right for under $100, and tell me if anything is not working the way it should (WUR). Thanks for the suggestions.