4.6L "Modified Poor man's" stroker

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Radioactivexj
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Re: 4.6L "Modified Poor man's" stroker

Post by Radioactivexj »

So we tried starting her up today after putting trans fluid, coolant, and motor oil in and she only cranked the first two turns of the key then she finally fired up for all of about 15 seconds, it rev'd really high btw about 3-4,000 rpm at the most, then she died again. We tried again 2 more times and had the same results. Anyone think they can help troubleshoot? I've checked the intake manifold for leaks but it looks pretty fluch against the cylinder head. We even recent the ECU and still no change.. :frustrated:
sly-jeeper
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Re: 4.6L "Modified Poor man's" stroker

Post by sly-jeeper »

Vacume leak under manifold, problem with IAC, throttle plate properly installed and or gaped right if it was bored just to name a few things
Radioactivexj
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Re: 4.6L "Modified Poor man's" stroker

Post by Radioactivexj »

Were running a stock throttle body for now so its not the throttle plate. I think were going to take the intake manifold off and re-install it to make sure i didn't put it on wrong. Hopefully thats the issue. I'm itching to get this thing running... :rockout:
Radioactivexj
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Re: 4.6L "Modified Poor man's" stroker

Post by Radioactivexj »

Well i tightened down all the intake manifold bolts and tried starting her again and she went straight to 5,000 rpm and stayed there for all of 20-30 seconds then we decided to cut her off. The only thing that may be a clue is that the gas pedal doesn't come all the way up where its supposed to. Its like its resting really close to the floor. I would say that this is the problem but the throttle cable doesnt seem like its being pulled at all without the pedal being touched. :huh:
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SilverXJ
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Re: 4.6L "Modified Poor man's" stroker

Post by SilverXJ »

Disconnect the throttle cable from the throttle body and see what happens. Its either that or a massive air leak. Running an engine at 5000 rpms under no load is a bad idea.
Radioactivexj
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Re: 4.6L "Modified Poor man's" stroker

Post by Radioactivexj »

SilverXJ wrote:Disconnect the throttle cable from the throttle body and see what happens. Its either that or a massive air leak. Running an engine at 5000 rpms under no load is a bad idea.
Yeah i know but we were only running it to see if the problem was fixed by tightening the bolts up. As he was turning it over and it fired up and went up that high i could visually see the throttle cable not move at all. I'm leaning towards the massive air leak at this point. We tried several things such as disconnecting the throttle body sensors one by one to see if it changed anything which it didn't. We plugged the hole in the manifold that we assume is the cruise control hose because we thought it may be loose it didn't seem to change anything. We were suggested to try replacing the IAC with a good one. If thats not it then we'll try taking off the intake and exhaust manifold and putting them back on and see if that works.
wjtom
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Re: 4.6L "Modified Poor man's" stroker

Post by wjtom »

If you take the iac off and just plug the hole the pintle goes it will just run at base idle.ie wherever the throttle body is set.should be around 650rpm.all the iac does is make a controlled leak.If it idles with the hole plugged the iac or possibly the tps could be bad.Check the voltage on a scanner should be under 1 volt at idle.Could check it at the tps also with a dvom.If the pcm thinks its off idle its going to open the iac.No need to waste money throwing parts at it with a few simple checks.
Radioactivexj
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Re: 4.6L "Modified Poor man's" stroker

Post by Radioactivexj »

Well after a long day of working on her she finally idles like it should. No more straight to 5,000 rpm on firing up. I took off the intake manifold cleaned it out and put it back on with right torque and everything so that was the issue. So i put her in reverse and she moved about 2 feet and stopped. I put it in drive and it wont move at all. It's like the transmission isnt shifting maybe? But all it would do is rev when put in any gear. Should I check my shift linkage? This thing is just giving me one problem after another... :banghead:
Radioactivexj
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Re: 4.6L "Modified Poor man's" stroker

Post by Radioactivexj »

Well turns out we forgot to top off the transmission fluid so thats why the tranny wasn't playing nice.. :lol: And after troubleshooting why it was staying in 4wd we finally got it to shift back into two wheel drive and took her around the block! She runs and drives now! :cheers:

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Radioactivexj
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Re: 4.6L "Modified Poor man's" stroker

Post by Radioactivexj »

Well we've ran into a little more trouble that we need to fix before we put tags on it. When driving it seems like it has almost a constant misfire that is their when you accelerate and when giving it no gas. After some reading im thinking the distributor may be a tooth off? Also it may be completely unrelated but the idle starts out fine when just sitting their but stays around 2,000 when you are driving around. So could that be either a TPS or IAC problem?
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SilverXJ
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Re: 4.6L "Modified Poor man's" stroker

Post by SilverXJ »

Radioactivexj wrote:After some reading im thinking the distributor may be a tooth off?
Could be. Its frequently the cause.
Also it may be completely unrelated but the idle starts out fine when just sitting their but stays around 2,000 when you are driving around. So could that be either a TPS or IAC problem?
I would check the TPS first.
Radioactivexj
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Re: 4.6L "Modified Poor man's" stroker

Post by Radioactivexj »

So were 100% sure the distributor is right. It still has a chug chug chug kind of idle like maybe its not firing all cylinders? It also dies after idling for 5 minutes or so and is varying idle from 800 to 1100 rpm. I have yet to get an obd2 scanner on it because mine broke. Just trying to get this thing runninng reliably.
Radioactivexj
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Re: 4.6L "Modified Poor man's" stroker

Post by Radioactivexj »

I also forgot to mention that i'm getting really low oil pressure readings. Like 4-5 psi low and thats after it warms up. So I guess that means i have a couple things to fix. Edit: Alright so I just started it up again and oil pressure went straight to 30 psi then to 40 so that seems ok. But the surging at idle is still bugging me. It'll idle at 1,000 rpm then go up to 1,100 then what I would describe as the engine faceplanting at idle and dropping back down to 900 rpm. And it keeps doing this. It can't just idle at a certain rpm. TPS connector reads 5.5v coming into the sensor at idle.
wjtom
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Re: 4.6L "Modified Poor man's" stroker

Post by wjtom »

What does it read on the signal wire?It should be somewhere between .5and 1volt normally.Sounds like you checked the 5 volt reference wire coming from the computer.
Radioactivexj
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Re: 4.6L "Modified Poor man's" stroker

Post by Radioactivexj »

The other two wires read 0 volts.
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