5.7 tbi swap to another tbi swap problems...

[superninja427]

Ok, Im new to this forum but i do have a few questions right off the bat. I put another 5.7 tbi motor in my truck and everything is hooked up, but i do have exhaust leaks. Im to the point of setting the timing. Me and my buddy dropped the distributor in at TDC and hooked all the plug wires up. I cranked the truck and i can adjust the cap to where it idles at the right rpm, but when it runs right and doesnt backfire through the tbi, it idles at like 2000. When it idles around 650 (what it used to idle at before i pulled the old motor out), it backfires through the tbi and runs like crap....my check engine light comes on automatically too. I have a 91 5-speed with a 5.7, the motor i put in it is from a 92 though. This is my everyday driver so theres not much done to it besides a streetfire coil, a tbi spacer and cold air intake...by the end of the week i will have long tubes and cheap mufflers due to the fact Iam out of money till next paycheck. Anyone know why my truck is running this way and why my check engine light is on now? I think that maybe when my buddy and I dropped the distributor in the #1 cylinder might not have been all the way to the top of the compression stroke and maybe the distributor is a few teeth off...but i dont really know much about timing and everything with these throttle bodys. So does anyone know what kind of problem Iam talking about and why its doing it? also what might i do to fix it? I would really appreciate the help.

 

[dirtridinz71]

To set the timing you need to unplug the est wire, its a tan wire which should be found by the relay panel on the firewall. As for the SES light being on you can check the code with a paperclip. Use it to jump across the top 2 right corner slots on the obd plug in. Turn key to run position and count pattern that the ses light flashes. It could be as simple as qn unhooked sensor.

Timing should be set to 0*.

 

[superninja427]

When i was setting the timing i had that tan wire unplugged byt the way, forgot to add that to my post. But what exactly do you mean by count the pattern that the SES light flashes?

 

[dirtridinz71]

The SES will flash in a certain pattern for the code given, it will do the code 3 times. The first sequence will be 1 flash, pause, 2 flashes (Code 12), this is just a code to show that the diagonstic port is working.

 

[MOBS]

It'll flash like a ship's morse code....

You need to run the #1 piston to near top of compression stroke, then dial it into place with the harmonic damper mark/gauge, then set your dist in and make sure your rotor is pointing to the #1 plug or right after it, this way you'll be dead-on or close. Depending on where you want your base advance set to.

 

[superninja427]

Also, recently just realized that at an idle, no matter ifthats at 2000 or 650, my throttle body is sucking air way more than usual..like its whistlin for more air than it really needs...I really think that's why its idling so high. Anybody know what that might be?

 

[MOBS]

The tbi is normally very loud anyways, but it could be that your IAC(Idle Air Control) valve is all the way out, letting the idle run very high. Also it could be an air leak, make sure all your vacuum lines are either hooked up or plugged off at the tbi base plate and intake manifold. Make sure all intake gaskets are good. Has your throttle stop been adjusted? Is your throttle cable adjusted correctly....too tight and it could mess with idle....but doubt it would cause your low idle issue.

 

[superninja427]

Nope. That plug hasn't even been popped out of my throttle body yet. I was thinking it was a loose intake bolt or a vacuum line was loose but I have checked everything. The iac valve is what I replaced about an hour ago and its still sucking more air than it should which is what I think is making my idle so high. Im all out of ideas honestly. I'm just gunna buy another bottle of carb cleaner and seat it everywhere on the intake and tbi until I here it mea with the idle. There has to be a leak somewhere is what I'm thinking.

 

[Tinbender59]

could be that the EGR valve is open, carbon build up??? who knows??? also get those error codes posted for us. SES light = Check engine soon light, ALDL connector is under the drivers dash, jumper the black/white wire to the white/black wire. then turn on the key to get the codes. Do not start the motor.

 

[1997chevydriver]

To check your codes, find the OBDS connector under the dash.
It looks like this:
|_|_|_|_|_|_|
|_|_|_|_|_|_|
Get a pad of paper and a pen.
Turn the key off. Turn off your blower, stereo, etc....
Put the jumper into these two pins:
|_|_|_|_|x|x|
|_|_|_|_|_|_|
Turn the key on, don't start the engine.
Watch the SES light. It will flash numbers (always in pairs).
It will generally start with a code "12", which is one flash, pause, then two flashes, and another pause.