anyone have a problem with a efi 460 running awesome when the motor is cold and then when it gets up to temp it leans out and runs like crap (no power) the manifolds will glow red. I have done everything, timing, every sensor, fuel pressure regulator and new pumps. i know that i have a miss. i did pull wires off one by one off the distributer, everyone indicates a miss but number 3. it has spark and it's burning, but when you pull it off the distributer it doesn't change a think. pull the valve cover off and checked spings and pushrods every think is good there. this truck is a fresh rebuild too. help!!!

 

You're not alone...I seem to be having the same problem with my 88', but mine is a fuel issue i believe.
Rich

 

Yeah me too, think i have a bad injector. Let me know what you come up with

 

If your exhaust manifolds are glowing "red hot" as you say, it probably means that your exhaust system is not flowing to remove spent gases. You may have a blockage such as a plugged catalytic converter, muffler or exhaust pipe.

By the way, running your exhaust manifolds that hot causes burnt valves, damaged valve seals, cracked exhaust manifolds and broken exhaust manifold studs. Very expensive to repair.

1989 460 cubic inch motors have many issues with catalytic converters.

Before I went further, I would check for codes. You can't do much without knowing what codes your motor gives you. Please get a code reader. Then I would replace the spark plug wires, distributor cap and rotor.

Replacing all those sensors, regulators, pumps and related items was much more expensive than a code reader. Modern engines are quite sophisticated and will tell you whats wrong if you are willing to listen.

I'm also a lot more willing to listen and help if spelling, punctuation, sentence structure and grammar are in keeping with our English language.

 

Ok.. I have done everything possible. I do have a code reader for OBD1, did that first, even had my snap on scanner on it as well (which really won't tell you anything since it's OBD1). Hell even had a breakout box. I have no codes present. I don't have Cats on the truck, and exhaust is not plugged, it's new as well as everything else beside the injectors. I am aware of burning the valves running it that hot. wires plugs and distributer is new as well. so i am going for injectors now.

 

It sounds as though you are eliminating a few things.

So:
1. No codes
2. Is the fuel pressure in range. I can't recall for sure, but it seams that you would like to see 45 lbs. all the time and especially under load.
3. Check to see if there is spark to all cylinders. Even the OBD1 should check this. Check your wires. Is there a hot enough spark to burn the mixture?
4. I'm sure the plugs are the right heat range and not shorting out. Right?
5. Put a timing light on it to check the advance curve. Mark 10 degrees BFTDC and 30 degrees BFTDC.
6. The glowing exhaust manifold throws me. It is either a whole lot of unburned fuel, a plugged exhaust or wrong timing. If the exhaust is open, then the fuel is being pushed out the exhaust valve to burn in the exhaust manifold.
7. It could be the injectors, but it seems odd that more than 1 would go bad unless the fuel pressure is overwhelming them.

 

1. no codes

2. I have 32 to 35 lbs of fuel pressure at idle, unplug the vacuum line and it jumps up 10 lbs to about 45 lbs.

3. have pulled all plugs everyone is burning clean and fine. just when it's idle you can tell there's a miss. you start pulling plug wires as it's running to see which one is causing the miss. all of the plugs made it miss more but number 3. it didn't change anything. but there is spark and burning fine. so that cylinder is prolly the issure.

4. sure, don't see why they wouldn't be doubt that's the issure

5. timing light has been on a number of times, timing is good.

6. I have seen red exhaust before and it can be a number of things, i am just saying that hoping someone has had the same issure. and it's just half the manifold, number 3 and 4 are red and the pipe doesn't get red. I have seen them get red from a vacuum leak before.

7. I didn't say all injectors was bad. I just don't like changing 1 injector and not replacing a the rest. i rather them all be new. I found out that a bad injector will cause most of my issues. Like a miss at idle, hard start when hot. it will start right after you shut it off but if you wait say 5 or ten min it will just crank and crank and act like it's going to pick up and start spit and sputter and die. cause for that would be leaky injector. it runs good cold and when it gets warm it runs bad.

note that i have tried new computer and i have changed my control module as well. i really don't see my heads being my issue either, as they were rebuilt as well.

 

Look at the new ECU, try to swap it for a know good unit, and make sure your balancer hasn't slipped throwing the timing marks off. If you were running retarded timing it could cause what you're describing.

Good luck!

 

that's a good idea looking at the balancer, i will look at that. But if my timing was off wouldn't that show up on a vacuum test. we checked that at i was good there as well. I didn't think i had enough or had a leak somewhere. but all checked out ok. your right it does seem that way that it's retared. I have put a new ECU in. so... everyone has had good input but seems that i have done about everything. like i said there was a guy that had a 460 and was doing the same exact thing. he pretty much went though everything i have, he went to jegs and bought new injectors and bam fixed it. seemed that one was clogged or leaking. i will check the balancer. that it possible i guess.

 

if it interests anyone, i have 8 new motorcraft injectors and 1 o2 sensor for 88 460. looking to sell. pm me if interested

 

alright, got back to working on the truck this past week. double checked everything. the fuel pressure seems to be good.when you turn the key on it's 40 lbs, while it's running 36 lbs, when you give it gas it's between 40 and 45 lbs. but here is the kicker, when you hold the release button on pressure gauge to check volume and left off, the fuel pressure is erratic, jumps from 36 to 20 lbs. if you feel the injector rail you can fell it there pulsating. it stays that way even if you shut the truck off and turn it back on again. i was thinking of changing the fuel filter. test lighted everything for the pumps. everything checks out there. cylinder 3 still seems week, compression it good, but you unplug 3 there is hardly any change, you take any of the others off and it drops about 100 rpm's. maybe new plug wires. it seems to be running really rich, the plugs are black. the timing is good, and advances to 30 as well. i need to put new manifold gaskets on since both are leaking now, thinking maybe that is throwing the 02 for a loop and also making the plugs hotter and shorting out. i did change the injectors but nothing changed. I guy i know still thinks it's in my heads. but compression is good revs up fine, just has no power when warm, hard start when warm, spits sputters after you get it started when warm. also there is a slight miss at idle even cold. seems you put a strain on the fuel and it acts up.

 

Was this a stock rebuild?

 

yeah it was a stock rebuild

 

think i may have found my issure!! i thought i had it in time. it have set the timing at at 10 with the spout out and it runs and advances like it's suppose to. but the kicker is, i was running it last night and shut it of. pulled the distributer cap off and the rotor was on number 1. looked at the marks on the crank and there not even close to 0. it's well past 30. so i pulled plug 1 and this piston was almost up all the way. so i turned the crank a bit, got the piston up and crank mark on 0. the rotor button on the distributer was past 1. pretty much between both contacts on the cap. so i think i am out. just seems wierd i can get it set on 10 degrees and it's running, plus the way it runs cold and then seems lose a little power when it warm and have a hard time starting after sitting for a few mins.

 

When you are at TDC and then pull your distributor cap the rotar isn't going to be pointing strait at #1 if your advaced 10 degrees the rotor should be right where you say it's at between the two. So i would firmly say thats not the problem