Cold start issues (below zero)
Thread Starter
|
Senior User
Joined: Apr 2002
Posts: 197
Likes: 0
From: in a house
Cold start issues (below zero)
Looking for any ideas:
I have a 98 Navigator that I just rebuilt the engine in. It has PI heads with a Lightning supercharger. Last year it started/ran just fine in the zub-zero temps.
Now when it starts it sounds like the lifters have pumped down and won't pump back up. When it is really cold you have to hold the throttle to the floor and turn it over for almost 5 minutes (seriously). When it starts it dumps huge clouds of white smoke and runs very very bad for around 5 minutes - the whole time you have to keep RPM's at 2,000 or higher or it will die. During this time you can smell the extra gas in the exhaust - this could be from too much gas being injected or from it not firing properly.
I think it is a bad sensor but can't figure out which one -
Thoughts?
It is -20 this morning, I don't even want to go start the truck!
I have a 98 Navigator that I just rebuilt the engine in. It has PI heads with a Lightning supercharger. Last year it started/ran just fine in the zub-zero temps.
Now when it starts it sounds like the lifters have pumped down and won't pump back up. When it is really cold you have to hold the throttle to the floor and turn it over for almost 5 minutes (seriously). When it starts it dumps huge clouds of white smoke and runs very very bad for around 5 minutes - the whole time you have to keep RPM's at 2,000 or higher or it will die. During this time you can smell the extra gas in the exhaust - this could be from too much gas being injected or from it not firing properly.
I think it is a bad sensor but can't figure out which one -
Thoughts?
It is -20 this morning, I don't even want to go start the truck!
Thread Starter
|
Senior User
Joined: Apr 2002
Posts: 197
Likes: 0
From: in a house
I think I figured it out! My IAC (Intake Air Charge Sensor) may be to blame.
One thing I have found is you can disconnect almost any sensor on a Ford Car/Truck and it will still run. For example if you disconnect the ECT (Engine Coolant Temperature sensor) the EEC will just ignore any tables that reference the ECT. It will not compensate for that sensor. You will throw a check engine light but the car will run fine.
I had tried the ECT and it didn't help.
This morning - it wouldn't start, exact same problem. Normally it would take 5 minutes to start and another 5 minutes to run right once it started. I pulled the ACT connector and it started right up!
I will test again later today (still -15 here).
One thing I have found is you can disconnect almost any sensor on a Ford Car/Truck and it will still run. For example if you disconnect the ECT (Engine Coolant Temperature sensor) the EEC will just ignore any tables that reference the ECT. It will not compensate for that sensor. You will throw a check engine light but the car will run fine.
I had tried the ECT and it didn't help.
This morning - it wouldn't start, exact same problem. Normally it would take 5 minutes to start and another 5 minutes to run right once it started. I pulled the ACT connector and it started right up!
I will test again later today (still -15 here).
Post Fiend
Joined: Jun 2003
Posts: 5,983
Likes: 2
ACT sensor? Did you mean IAT? What is an IAC *sensor*? The IAC (idle air controller) is a motor that meters the amount of air to the engine to govern idle speed. I'm sure disconnecting it may have some effect but I would have no idea which.
Thread Starter
|
Senior User
Joined: Apr 2002
Posts: 197
Likes: 0
From: in a house
[A]ir [C]harge [T]emperature sensor. The sensor that is in your intake runner that measures the temperature of the air before it enters the combustion chamber - especially important on supercharged applications because of the heat caused by the compression of the charge air.
Post Fiend
Joined: Jun 2003
Posts: 5,983
Likes: 2
Oh man, I don't have one of those. I now have ACT envy. I only have an IAT. You got one of those too (upstream)?
In your mail you call your Intake Air Charge Sensor 'IAC'. I call an IAC an Intake Air Controller.
Yea John, I'm giving you crap.
In your mail you call your Intake Air Charge Sensor 'IAC'. I call an IAC an Intake Air Controller.
Yea John, I'm giving you crap.
Thread Starter
|
Senior User
Joined: Apr 2002
Posts: 197
Likes: 0
From: in a house
My bad - too many terms! Actually I am not sure which one is right!
It was the doohicky that checks the intake air temp!
The Expedition/Navigator does have one but it is just after the air filter in the intake ductwork. On the supercharged Lightning they put it in the intake runner.
It was the doohicky that checks the intake air temp!
The Expedition/Navigator does have one but it is just after the air filter in the intake ductwork. On the supercharged Lightning they put it in the intake runner.
Thread
Thread Starter
Forum
Replies
Last Post
jmarro1
1987 - 1996 F150 & Larger F-Series Trucks
25
Sep 21, 2010 06:03 PM
itlkick
Lightning, Harley-Davidson F-150, Roush F-150 & Saleen F-150
2
Feb 8, 2004 08:08 PM
jimfrentress
Small Block V8 (221, 260, 289, 5.0/302, 5.8/351W)
1
May 31, 2003 10:43 AM
