Hard to keep running when Cold

[mproseusa]

I just finished the TB WP change out on MY 82 928. Prior to that job, I had a no-start condition. The Timing belt which was several years old had jumped two or three teeth on the passenger side cam. Anyway when I finished job, I was pleasantly surprised that the engine fired right off. However, the engine would not keep running unless I modulated the throttle. Once the engine warmed up, it idled and ran fine with good acceleration (for an ’82). I’ve looked around for any loose vacuum line and wire connections, but I believe everything is O.K. Would the Cold Start Valve be suspect? I have not yet checked the resistance of the Temp Sensor II or the Temp Time switch but will as soon I get some time. I thought someone may be able to pinpoint the problem quickly.
Thanks for all your suggestions and all the help you’ve given me in the past.
Mike

[aluminum]

I would go back to the "Vacuum leak " first and check for that >
Neat Trick : Park outside and with motor running at Idle run a water Hose at low Volume over all the V. Lines / Intake Ports Injector seals back of motor any where and you might think of that has Vacuum like the Air Box in to the Motor seal Etc .
if the motor slows down you just found a leak as a bit of water is sucked in ( well not hurt it )
If a leak is bad enough steam Vapor well come out the Tail Pipe.
Its a Neat trick because you can do the whole motor in a few Min's
Could be lot's of things but they have so many Vacuum areas I would Re-Start there first .
*************************************
Naturally don't water the electrical connections > like injector wires Etc .
______________________________________
Then move on to other area's if nothing comes from that .

[mproseusa]

Thanks for the tip aluminum. I give that a try tomorrow.
Mike

[mproseusa]

I stumbled on to the reason I had a problem starting. I checked the Time Temp sensor and the Temp II sensor and they checked out OK. I also checked the cold start valve and it also was O.K. I did some additional work on the engine and between jobs I would take it for a ride. Every time I had to modulate the throttle to keep it running until it got warm. Once the engine was warm, it ran fine. I replaced some fuel hoses and cooling hoses and when I got the engine running, I would check for leaks, etc. I noticed an air leak noise. At first I thought it was an air leak around the O-ring on the Mass Air Flow meter. But as I moved around the engine the sound got louder near the Intake Distributor. I found that one of the rubber sleeves connecting an intake tube to the distributor was cracked and leaking. Since I didn't have another sleeve, I was able to move the old sleeve over and tighten the clamps to seal the leak. The next day, with the engine cold, it started right up and came to an idle with no problems. I let it sit for another day, and the engine started with no problems. I can now move on to other items on my TO-DO list.
I thought this may help others that may have the same symptoms.
I need to check with MPDANO to see where he got the blue sleeves for his baby.

[Maleficio]

Cool. Glad to hear it was an easy fix.

[MPDano]

Originally Posted by mproseusa

I stumbled on to the reason I had a problem starting. I checked the Time Temp sensor and the Temp II sensor and they checked out OK. I also checked the cold start valve and it also was O.K. I did some additional work on the engine and between jobs I would take it for a ride. Every time I had to modulate the throttle to keep it running until it got warm. Once the engine was warm, it ran fine. I replaced some fuel hoses and cooling hoses and when I got the engine running, I would check for leaks, etc. I noticed an air leak noise. At first I thought it was an air leak around the O-ring on the Mass Air Flow meter. But as I moved around the engine the sound got louder near the Intake Distributor. I found that one of the rubber sleeves connecting an intake tube to the distributor was cracked and leaking. Since I didn't have another sleeve, I was able to move the old sleeve over and tighten the clamps to seal the leak. The next day, with the engine cold, it started right up and came to an idle with no problems. I let it sit for another day, and the engine started with no problems. I can now move on to other items on my TO-DO list.
I thought this may help others that may have the same symptoms.
I need to check with MPDANO to see where he got the blue sleeves for his baby.

I bought a Blue Silicone Tube off eBay a couple years back. I need to locate one and see I can measure it for you. You will just need to mark them with a pencil and use an Exacto Knife very slowly to make the cut. Silicone cuts like butter with a sharp blade, too easy that you could easily make a bad cut in a hurry.

[mproseusa]

Thanks Maleficio and Leo. I'll check at some local auto-parts stores and Lowe's to see if they carry anything like it.

[MPDano]

Here's some pics of mine. Still looking for the tube size

[mproseusa]

Wow,
Awesome! Thanks for sending the pics. and looking for the dims.
Mike

[MPDano]

Here's some cut to order stuff:

45mm Blue Silicone Tube

CUT BLUE 45mm 1 3/4 SILICONE HOSE PIPE VENAIR SILICON | eBay

1 3/4" 45mm HPS 1 Foot Long Silicone Coupler Tube Blue | eBay

You'll need a little less than 2 feet or it.