4AG 16v Throttle Unresponsive

P3nnyw1se
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4AG 16v Throttle Unresponsive

Postby P3nnyw1se » Sun May 01, 2016 3:36 pm

I'm making progress on my car and have the tube for the AFM now. Used a silicone 2.5" to 2.75" to take care of that. I can get the car to start but it only runs when the pedal is floored. It chugs but the engine never goes above 800 or so RPM. I'm stuck as to what would cause this. I'm going to check the injectors to make sure they're getting 12v of power to each one when they key is turned to on. Would the order in which they're plugged in affect how the engine would run? I mean they only plug in in pairs so I figure they can be crossed and will still send the same pulse signal within those pairings. Other than that I have the Starter Relay jumped because even with the clutch switch connector jumped nothing would happen. Everything has been grounded properly. Cylinder head to chassis, block to chassis, injectors to manifold, chassis to transmission, fuse box to chassis (for the injectors I think or something.) AFM to chassis, and the fuse boxes are all bolted down inside. ECU is as well but only with a single bolt. I think I'm going to try adjusting the TPS a little bit and checking that too just to make sure it's adjusted properly. I might swap out the ECU to test with another one also just to rule that out. I've got a spare handy. The only other things is that the injectors may not need the resistor box. But they're the green cased ones which I think came stock on the Bigport 4AG.

sirdeuce
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Re: 4AG 16v Throttle Unresponsive

Postby sirdeuce » Sun May 01, 2016 6:43 pm

Did you check your timing belt? Jumping a tooth would make idle hard, two teeth and you'd have to keep the revs up.
One shot, one kill.

P3nnyw1se
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Re: 4AG 16v Throttle Unresponsive

Postby P3nnyw1se » Sun May 01, 2016 6:51 pm

Yeah. The belt just slid right in place when I installed it. All the marks match up on top and bottom and there wasn't any slack and I was pulling it tight too just to make sure...I'll take a video for you guys...also can someone delete the double topic? I should say that I don't have the idle up installed to the front of the throttle body either. But I think the car should still work normally even with that out.

My TPS is adjusted properly and the AFM looks fine. I tried to poke one of the injectors and it just kinda pinged 12 volts but wasn't constant. Sometimes it read as high as 19 and as low as 5 volts. It lasted for a second or two each time it was pronged. I'll check the timing again and refit the belt just to be sure it's properly fitted and not jumping teeth. What are the odds that it could be the coil? What else should I check and rule out?

sirdeuce
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Re: 4AG 16v Throttle Unresponsive

Postby sirdeuce » Mon May 02, 2016 10:37 pm

On the idle up solenoid, did you plug the hole at least? It's a big enough leak to kill the engine at idle.
One shot, one kill.

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Jeonsah
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Re: 4AG 16v Throttle Unresponsive

Postby Jeonsah » Tue May 03, 2016 6:57 am

Distributor installed correctly? At TDC (crank at 0, cam gear dimples matching backing plate marks) the dizzy rotor should be pointed at the #1 lead.

P3nnyw1se
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Re: 4AG 16v Throttle Unresponsive

Postby P3nnyw1se » Tue May 03, 2016 11:21 am

I just re-sat it. But I still think the cams might be a tooth off. It revs up to about 4K now before it'll start to backfire like crazy. When I let off the throttle the car will just die but I think that's because I took out the idle up. I've got a coolant leak I need to fix and smoke coming from somewhere in the exhaust system I believe. Another question though, are the OBX Stainless headers supposed to glow red hot? Everything down from by header to the input on my cat is glowing which worries me.

Edit: Adjusted the distributor and that seems to have fixed the issue. Now though the car won't stay running if I let off the gas/throttle. How do you adjust the opening of the throttle plate? It doesn't seem to be letting enough air in to keep the car running. The idle mixture screw works fine while I'm holding the throttle open just a tad...so I'm a bit confused about that.

Post Edit: Got the engine running just fine now with the timing adjusted and all. Turns out the crack in my brake booster hose was causing it to lose enough vacuum to keep the car from running. I capped it off and it's running like it should now. Now I've just got to get some 5/16" hosing to route to the booster line and it should be all good to go. Thanks for the help guys!...I guess the thing to take away from this is triple check all your vacuum bits to make sure they're all good.