Danny Davenport

Hi folks,

Bought a 95 T/A from a buddy. Headers, exhaust, rebuilt T56, yadda yadda. Anyways, he did the throttle body bypass, but i think it may have been done wrong. The car overheats after a little bit. Radiator has seen better days, but before i drop a new one in, i want to make sure the bypass isn't at least partly the culprit. I only see one plugged port on the TB, and for the life of me, I can't figure out how this whole thing is routed. Here's what i see:

Elbow on lower driver's side of the throttle body is capped. Lower passenger side is open. Steel line from back of passenger head is run to the radiator, 2nd port down from the cap. Hose from top of passenger valve cover is run to top passenger of TB. Steel line from back of driver head turns up under the TB, towards the intake.

Does this seem right? Everything i've read on here says a double barb should've been used to tie the inlet/outlet together, but i dont see that anywhere. The steel line from the passenger head looks like it may have once been tied to the passenger side of TB, but where did the driver's side port of the TB come from/go to? Can anyone make sense of this for me?

Thanks.

hrcslam

Not sure what steel line you are talking about from the back of the drivers head. Pictures would help. Everything else sounds right.

What are the symptoms of the overheating? Did you re-bled the system properly?

Danny Davenport

My mistake. That steel line runs from the driver's side top of the intake, to underneath the throttle body. Thought it mirrored the passenger side.

The car overheats after about 10min, or so. Temp gauge climbs steady, and i can feel/smell it getting hot. I haven't bled the system yet. Guy i bought it from said he runs Water Wetter. Radiator has rust at the bottom of the stick.

It also feels like it goes into limp-home after a few laps around the neighborhood. Like it's tripping knock sensor, or saving me from overheat/blowup. Dude says he swapped an lt4 ks in it.

Trying to diagnose this thing, through process of elimination.

Thanks for responding.

shbox

Sounds like the bypass was routed correctly. No barb needed on 95 and up. Capping the hose pipe ends on the TB is optional.

http://shbox.com/1/tb_bypass.jpg

hrcslam

Start with bleeding the coolant system properly to eliminate that as a possible cause. If there's no air in the system, then check for air flow (fans/lower air damn/ clogged condenser/radiator fins) and coolant flow (which can be done when you are bleeding the system; when you are bleeding the system, if you don't have steady consistent flow once at about mid gauge and it's burping instead you likely have a bad water pump or spline drive). ]

Start with the easy stuff though. Bleed first. Is it boiling over when the gauge reads hot?

Danny Davenport

Update:

Ok, so I did some flushing today. **** was filthy. Bled it off, circulated, drained, filled, and then got rained out. Had to put the car cover back on. Will finish that tomorrow.

While it was idling, i was rearranging vehicles to get it back under cover. Came back to it and it died. I notice that the longer it runs, the worse it runs. This isnt a new development. I start hearing noise coming out of the exhaust, which i can only describe as "the sounds you hear when fireworks are launched". Not the explosions, but the thumps of fireworks leaving the tubes. The noise is not rhythmic. Just "puh.......puh..puh......puh.......puh....puh...pu h............puh..puh."

Then, it will die. And wont start back up. And the battery will be totally dead. Wont jump off either. Put it on the battery charger for a couple hours, and it cranks right up and runs like a champ for about 5min. Then it starts all over. No power when i stand on it. Spits and sputters. Gets hot. And then dies. And then i sit in a chair, light a cig, open a beer, and stare at it...

Help...

hrcslam

O.k, you need an ALDL cable (16pin) and download Scan9495.exe from Gary Doug (Google it), it's a free datalogs program made specifically for his like us. You'll need to see everything the computer is seeing. This is highly recommended for anyone with an OBD1 F-Body.

It sounds like your alternator is not charging your battery. Check voltage with the car running at the battery, it should be more than 13VDC.

The dead cylinder sound you are hearing is probably just that; random dead cylinders do to insufficient spark strength from a weak voltage source.

You could have other issues on top of that, but that can cause a lot of issues on its own. The cable is less that $60 IIRC, worth every penny.

Danny Davenport

Alright, so i did some more flushing today. That's looking better. Moving on from that.

I'd say you're right about the alternator. I charged the battery full and let it run through a flush cycle. Watch the batt. gauge, and sure enough, it drops, slow and steady. As it drops it idles rougher and rougher. And the detonations increase with it. So i look to make sure i wired the alternator back up when i deleted the a/c, and i put everything back the way it was before. Only problem is, im missing the plug that goes into the alternator! Im assuming tgere's a plug outlet on it for a reason. Got a small wire running out from the bottom, which i traced towards the dash, so im assuming its the control. Got my positive stud wired to the battery. And it's grounding through the bracket. So where is my plug? I looked all over for it to no avail. Where should it be going, so i can try to trace ot from the other direction? And how do i go about installing one if the damn thing's no where to be found?

Thanks for all your help by the way.

shbox

The alternator will not charge without that little wire to the dash hooked up.

http://shbox.com/1/harness2.jpg

http://shbox.com/ci/ci417.jpg

hrcslam

Yes, the plug for the alternator is located underneath it as installed just as shoebox showed in his pictures. Without that wire hooked up the alternator will not work. It's the signal wire from the pcm to the alternator that tells the alternator to make power.

Without that you'll have the symptoms you have explained. Overheating can be caused too because the battery won't have enough power to spin the fans fast enough (this only effects cooling at low speeds and idle).