7.3L engine is running away some...!

[boomvan]

Hello... upon a cold start at -30, on my 91 F250, the engine takes 5-10 seconds of turning over before it starts to fire off (i think I have an air leak in the fuel system, but only happens when its below 0), then once its running, it idles up to 1000rpm, then 15 seconds later its 1100rpm, then its 1200rpm, then its 1300rpm...... if i disconnect the cold advance and the fast idle, it will drop to around 600-700...
is it normal for the cold advance to raise the rpms up to 1300, or do I have something else going on?

I have a 750 watt block heater, a 1000 watt circulation coolant heater, 300 watt oil pan heater, 150 watt trans pan heater, and 1.5amp battery charger all going to get her started... it sucks some juice...

[George_7.3IDI]

Originally Posted by boomvan

I have a 750 watt block heater, a 1000 watt circulation coolant heater, 300 watt oil pan heater, 150 watt trans pan heater, and 1.5amp battery charger all going to get her started... it sucks some juice...

Damn... that's alot of juice. All I've got is a block heater and oil pan heater and my '90 F250 starts fine up here. I would look at air leaks in the return lines on the injectors as the first culprit to hard starting. You need to make sure that the return line caps on the top of the injectors are fully seated. As far as the up idling... I know that on a cold start the engine is supposed to idle closer to 1000 rpm and then once it warms up it drops down to about 600-700 rpm. Although to the best of my knowledge it shouldn't keep advancing until 1300 rpm. I would give you a call Tim as I think I still have your phone number from a few PM's a while back when I was hoping to meet up with you but it never worked out. I'm headed back east for thanksgiving for a week... when I get back I'll try and remember to give you a call to find out if you got the problem solved. If not we can see about diagnosing and solving it.

Good Luck. Also try checking out oilburners It's another forum where you can find help with these older IDI's... it's quite similar to TDS and there are several knowledgeable people there willing to help out. You'll have to google it because it's not letting me post the link.

[boomvan]

would sticking exhaust valves cause that rpm behavior? I have (what I believe to be) had an exhaust valve sticking at times... once its warm its ok however...

[cdnsarguy]

It sounds like you may have a fuel leak.... any wet spots on the filter header or IP or any lines ie return or injection.

Visit: Ford diesel 6.9 7.3 IDI check out air leaks and clear line test. Remember to use a pigtail loop in the clear lines.