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cranks and runs, but doesn't idle good then dies

09-09-2012, 08:31 PM
Okay, I have an 04 sport trac. I had a valve spring break. I pulled the head and had it rebuilt. I got everything back together and my timing was out 180. I'm just glad I didn't get it 90 out. It would have done some major damage. I got that fixed, then my intake manifold was leaking. I fixed that then my orings on the injectors were skinned. I fixed that and I really thought it would do the trick, no leaks and everything back together. Well it didn't get me back on the road, so I kinda put it off till cooler weather. I let it set long enough that I thought the fuel could have been bad. So yesterday, I removed and drained the tank, replaced the fuel filter, removed and cleaned the injectors, then put about 5 gallons of premium gas with lucas treatment back in it. The truck will start fine, but it will idle ruff, and die pretty quick. If I go to rev it up, it will rev, but dies quickly. My first thoughts would be IAC or TBPS. I'm here today to see if anyone had any ideas.

09-09-2012, 10:34 PM
Welcome to the forum!

With all the work you've done on the top of the engine, I'd start by looking for any damaged or disconnected vacuum hoses.


09-10-2012, 07:14 PM
Yeah, I would bet you are right about the vaccum leak. I have checked all the hoses pretty good. I think tomorrow I will check the torque on my intake manifold. I can remember the two by the firewall being tough to get to and it could be possible that I didn't get them good enough.
Also at the butteryfly valve on the throttle body I can hear and feel an extreme amount of air sucking in. This is probably normal, but it just seems like it is sucking too much and it's getting too much air.

09-10-2012, 07:48 PM
From everything I've read online, I'm starting to think it would be the intake manifold gaskets. I did replace the lower when I tore it down and I can remember that it was hard not to slide the intake and moving the orings. I know it needs to drop straight down without sliding. I'm thinking about finding a long bolt or rod to help me guide it into place. It's probably not the best idea, but would it hurt to add just alittle blue rtv to the orings. I'm talking about just enough to get them alittle sticky so they might hold in place better while I sit the manifold back in place.

09-11-2012, 05:03 PM
manifold orings didn't get my truck fixed.

09-11-2012, 05:06 PM
:banghead: I surrender. I'm calling the shop and tow truck in the morning.

09-14-2012, 02:38 PM
Well the truck is off to the shop. They said it will probably be a week or two before they could get to it. That's okay, it's only been sitting over a year. Even though this forum hasn't been that great of an experience for me, I will post what the mechanic finds.

09-15-2012, 10:56 AM
Thanks, we'll appreciate you letting us know what the shop finds.

Out of curiosity though, please send me a Private Message with your concerns/complaints with the forum. We're always looking for ways to improve and would love to get this forum back to being as active as it was only a year or so ago.


09-15-2012, 01:16 PM
Sorry you didn't get the response you expected. Sometimes the timing is everything. Maybe poor viewing on a Sunday night....maybe people were distracted with 9/11. Who knows. There are key people here that are 'tops' with deep problems like this. Maybe they weren't available. I know I haven't been around here for a while. I've posted problems on forums only to get no response and had to figure 'em out for myself.
Checking for vacuum leaks is the first thing I would have suggested too. Did you scan for codes? What did the cylinder and piston look like? Did you perform vacuum and compression tests to try and eliminate mechanical problems? Try spraying brake cleaner around the intake manifold while it was running? Check the fuel pressure regulator and PCV valve and its tubing? That excessive air around the throttle body could have been a leak. More info is always helpfull. Try us again and please let us know how it turned out.

09-15-2012, 03:25 PM
Before I had it towed to the shop, I went ahead and put the duct work and filter back in. I really didn't think it would make much difference, but it got it to idle before it went to the shop. After that, it would idle. Now I can't rev it up without it dieing. Anyway, I took the truck to the best mechanic in town. I will definitly post what he finds.

10-04-2012, 08:04 PM
So the mechanic couldn't find anything wrong with it. He first thought the timing was off. He tore into it and it was fine. Then he took all the O2 sensors out and it would actually rev up to 3000 and the limiter would kick in. He said the thought my cat converters were clogged. I went online and found some magnaflow bolt on converters. Together they costed me around 256 for two cats together and 371 for the other 2. I used advanced auto and they had a promo code for 50 off. Then my wife bought the other half and got her 50 off. That brought my total to around 578, not too bad. I will post back if it actually cures my truck.

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