Maybe a a possible tune issue?!?!?

[etp2828]

I have an 04 terminator with 40k. I got it cheap but in fantastic shape only because the guy snapped the crank snout. I rebuilt the engine too. I ported the cylinder heads and replaced the valves, ported the intake and supercharger as well. I also changed the valve springs to comp cams valve springs that support .500 inches of lift. I still have the stock cams in place. Now when I started it up, it idled perfectly and I drove it down the block and back up the street. Once I came up the street it started running rough and idled rough as hell and still does currently. I tried the frps and fpdm and nothing changed. I changed the plugs and nothing changed. I pulled the pumps and checked them to make sure they're good. I had the injectors cleaned and nothing changed. I checked the fuel pressure and it is about 40 psi and it bounces around a few psi here and there. I checked the coils as well and they're good to go. I am beginning to think there may be a tuning issue now. When I got the car it had a tune from an old tuner back in 2004. It looked to be from one of the first sct tuners that came out. Any input on this would help because I am seriously stumped now. Something like this I would have usually figured out by now.

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[beastmar]

Could be a tune issue. But it just doesn't make sense why it did work and then it didn't if you didn't change anything in between. I would check for vacuum leaks. The 90 degree rubber elbow behind the blower is known for cracking and breaking.

 

[etp2828]

Could be a tune issue. But it just doesn't make sense why it did work and then it didn't if you didn't change anything in between. I would check for vacuum leaks. The 90 degree rubber elbow behind the blower is known for cracking and breaking.

I deleted all of that. I have a 99 ford lightning that I deleted the elbow on and I have no issues at all. The guy I bought it from had a 4 lbs lower and a 2.65 upper with an intake and tune and it put down decent numbers with that old tune. All I have on it now is the stock lower and a 2.8 upper and the cold air intake and the egr deleted. Also since the issue cams along I noticed a heavy smell of fuel in my garage.

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[cj428mach]

If you're still running the stock maf and injectors or the maf and injectors it was tuned for you shouldn't be running into issues with the tune while out of boost. I'd say its something mechanical.

 

[gt347mustang]

Time for a compression and leak down.

You've got something mechanically wrong or if lucky a connector or something loosened up.

 

[cj428mach]

Now that I think about it, I think Malcolmv8 installed stock injectors and maf in his heads/cam/tvs car while doing some trouble shooting and I believe he said it ran perfect when loading the stock values in the tune.

 

[etp2828]

If you're still running the stock maf and injectors or the maf and injectors it was tuned for you shouldn't be running into issues with the tune while out of boost. I'd say its something mechanical.

I sure hope not. I'll pull the valve covers and see if I see anything.

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[etp2828]

Time for a compression and leak down.

You've got something mechanically wrong or if lucky a connector or something loosened up.

I hope it's the connector. I'm crossing my fingers on that one.

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[etp2828]

Time for a compression and leak down.

You've got something mechanically wrong or if lucky a connector or something loosened up.

I hope it's the connector. I'm crossing my fingers on that one.

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[etp2828]

I forgot to mention to also the other night I was messing with it to see if anything would fix the problem. Well I started pulling injectors one by one and soon as I pulled one particular injector the idle improved as well.

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[etp2828]

Well I pulled the plugs this evening and my number one plug was clean like I just put it in there. That isn't a good sign.

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[etp2828]

Well I pulled the driver side valve cover and sure enough a rocker arm came off. Doesn't look like any other signs of damage took place. Well if that's all that happened then I'm fine.

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[gt347mustang]

A single follower falling off isn't going to cause the issues you're describing.

Keep looking, hopefully you find the culprit.

 

[etp2828]

Well thats just the driver side valve cover. I still haven't check the other.

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[etp2828]

A single follower falling off isn't going to cause the issues you're describing.

Keep looking, hopefully you find then culprit.

I'm pretty sure that has a lot to do with it though. I'm not done looking yet.

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[cj428mach]

Odd that a rocker came off, hopefully it wasn't installed correctly. Most people with follower issues end up having valve seat issues.

 

[etp2828]

Odd that a rocker came off, hopefully it wasn't installed correctly. Most people with follower issues end up having valve seat issues.

Well the valve had to no signs of damage and it the rocker went back in tight.

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[etp2828]

Well pulled the other valve cover and a rocker was off. I put it back on and put everything back together. Fired her up and nothing changed. This point judging by how bad it's running I'm going label the issue in the heads and start getting her ready to be torn down and the heads rebuilt. Too many bad signs to ignore.

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[gt347mustang]

Well pulled the other valve cover and a rocker was off. I put it back on and put everything back together. Fired her up and nothing changed. This point judging by how bad it's running I'm going label the issue in the heads and start getting her ready to be torn down and the heads rebuilt. Too many bad signs to ignore.

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Bummer, but I wasn't expecting that to help.

Have you done a leakdown and compression check like I suggested from the beginning?

 

[etp2828]

I haven't did that yet. I'm pretty sure it won't be good either judging by the way it's running. I have thought about checking the intake gaskets, but I'm not convinced they're even bad.

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