I seem to have a leak out of the throttle rod area on both sides of the TBI. One is on the driver side where the linkage for the pedal/cruise hook up and and the other side...the passenger side is right at the throttle position sense. Seems like the passenger side is a more gross leak as more end up on the ground on the passenger side. What can cause this and what can i do. I've replaced fuel pump, fuel filter, fuel lines, and rebuild the TBI. I had a couple extra pieces out of the kit that they didn't tell me to use, i'm wondering what they were, one was a couple TINY clear plastic rings, and i mean like 1/16" of an inch big, another was a gasket that looked like an 8, only bottom loop was bigger than top. There was a similar gasket in the kit that i used for what ever it was for, i think it linked the unit with the fuel pressure regulator, but other than that, the picture didn't even show a use for it...like it was extra. Any advice or thoughts would be greatly appreciated.

 

any possible reasons fuel would be leaking out both sides of the throttle rod and any possible fixes???

 

Is the car running ok while this is going on or is it running poorly or not at all?

Is there gas coming out of the injectors right after you turn the key on but without starting the engine?

If the engine runs, does the gas coming out of the injectors look like a normal spray pattern or is there more dribbling out?

 

car did this before, i removed the TBI, cleaned it a 2nd time after rebuilding, put it back, fires RIGHT up perfectly, idled weird because the computer isn't getting any feed apparently from the coolant temp sensor, so it keeps dumping fuel in thinking that it needs to warm up, but anyways, it was fine for like a week or two, went to start it monday, and it's dumping fuel out the sides again.

not sure if the gas is coming out of the injectors as it's manual, and i haven't had a second person there to help me, but it starts coming out AFTER i stop trying to turn it over. I'll hold the key for 15 seconds, and it won't start, i'll stop turning the key, and then you'll see a small stream come out the driver side. I'm assuming the passenger side by the throttle position sensor is doing the same, but more comes out that side.

Before yes, the spray looked good, i rebuilt the whole fuel system and got to the point i was ready to replace the injectors for good measure, but at the time i got done with the pump/filter/lines/rebuilt TBI, i looked at the injector spray and it was a nice cone shape so i didn't touch the injectors yet.

I know the only issue is fuel getting into the TBI unit because if i spray starter fluid in there she'll fire for a few seconds till it's burned off.

 

anybody have any ideas or possible fixes??? Last step before paint...

 

i think its time to pull it off again and send it to a carb shop to have the throttle shaft bushed. or if you want to DIY then check out this thread:

https://www.thirdgen.org/forums/tbi/...w-rebuild.html

I also believe that you left out an o ring or "chopped" one while reassembling the tbi unit. Possibly tore a gasket. those are all the things that i can think of at this time.

 

i am going to look into this bushing setup. What do you mean by "chopped" one??? Just curious. There was literally no instructions in the kit. I mean it isn't rocket scientry, and they had 2 blown up diagrams that showed where every part went. I was left with like 3 extra parts...like i said, an 8 shaped one (of which i used the one that i was supposed to in the rebuild) and then 2 teeny tiny...possibly clear nylon bushings? Didn't have anything pictured for them. I will continue looking into these bushings though, thanks. This is a 1988 5.0L TBI (LO3) if anyone else can think of anything or if there is anything special to the '88s TBI that i should know about. Thank you!

 

"2 teeny tiny...possibly clear nylon bushings"

Those sound like the gaskets that go on the fuel inlet and outlet fittings that screw into the injector housing. The original gaskets usually stick on the end of the fittings so you probably didn't notice them. Its possible that these could be leaking fuel and its forming around the base of the unit, making you think its coming from the throttle shaft, so check that.

Even if the throttle shaft holes in the unit are pretty worn, unless something else is wrong with the unit its hard for me to understand why gas would be coming out of them. When you grab the throttle arm and wiggle it back and forth, does it have a lot of play? Does the unit show any signs of the throttle sticking, which often happens when the throttle shaft is worn?

Another possibility is you didn't reinstall the injectors correctly, as mentioned above an o-ring may be messed up. Another possibility is that you didn't index the injectors correctly. There is a little pin that has to be lined up correctly with a recess in the housing, if you don't have it right they will leak. The injectors also should fit all the way down in the housings so the ends are sticking out of the housing by about 1/16".

I think the problem is more likely one of the above than worn shaft holes.

 

the throttle arm has no play, thats what has me so clueless...the throttle has never gotten stuck on me...and it's very responsive. I step on the gas and it immediately responds, i let off, it goes down. No sticking to my knowledge...as i mentioned it didn't have instructions...just a blown up diagram...and i Xed out the part as i went...the instructions didn't cover the last 3 pieces...

i figured out the "pin" in the injectors...i got them head on...thats not the prob...and i looked at the injector from underneath and it looked tight all the way around...as i said...this engine HAS run after the rebuild...but it seems as though it's hit or miss...

can you please explain the tiny bushings some more...i saw no place for it...on the inlet there is a strainer type ring that they had me install, and then the rubber o-ring i think at the bottom (outlet) and then you slide the injector in...past that i don't know. I do remember there were a couple big rings at the top by the terminals for installation, but past that it's been 2 months since i've done it. It screwed up at first, took it apart cleaned it some more. Put it back in, it worked for a month dead on too...i let the car do it's 2 second prime and it fired RIGHT up, then let it sit for 2 or so weeks, started leaking like a sieve again.

 

"and i looked at the injector from underneath and it looked tight all the way around..."

Is the end of the injectors sticking out of the housing by at least 1/16" or so?

If not they're not seated properly.

Also you put on both o-rings, the small ones on the end and the big ones on the top?

The clear washers I'm talking about go on the ends of the fuel inlet nuts that screw into the back of the injector pod. You have to take these out to be able to take the injector pod off the unit.

I'd check carefully fuel for leaks or dribbles with the air cleaner off and the fuel pump on, without starting the engine. When you turn the key on the pump only runs for a couple of seconds to pressurize the system to get it ready to start, so have someone sit behind the wheel and turn it on and off.

Look around the regulator in the back for any fuel dribbling, you might have a crack in the regulator diaphram. Look at the injectors and see if they are dribbling. It just seems like you must have fuel leaking from somewhere.

Did you rebuild the regulator, and if so are you sure it was assembled correctly?

 

i believe they are sticking out 1/16" of an inch...like i said...been 2 months, but i can check fridayish.

i specifically remember 1 o-ring at the bottom (not that there wasn't a second), at least 2 on the top if i remember correctly. I may be wrong. I will post up the lame instructions i have so that everyone can see what i got to work with and with a blown up diagram you can use specific examples (like modify the picture with arrows and such)

i will check all that friday when i can get out of classes and have someone help me. I'm going to be pissed if the diaphram cracked...i was careful with it and everything.

I didn't touch the regulator other than to replace whatever gaskets and such that came in the kit. I was told not to turn the little thing because that would obviously adjust the fuel pressure, i didn't play with that at all. I just took the spring and diaphram out carefully and cleaned...put the spring back in...and then put the new diaphram in.

It's wierd...it's leaking out...and def not in the manifold...cause it will not start for anything.

 

Sounds like an o-ring to me. If you rebuilt it and then took it apart to fix something, that could screw up the o-rings at the top of the injectors. Once seated, they tend to stretch out and never fit again if you try to take them out and reinstall them. Also, when putting on o-rings, you should put a little vasoline or something on them when slipping them on or they could tear slightly and eventually leak. O-rings are usually the top things that leak when putting these together.

 

i read that and i read to use ATF fluid to aide in that problem. I dipped them all in ATF and then installed them via the instructions. It wasn't so much to "fix" as it was just for precautionary to rebuild. Used everything original but the gaskets and such.

 

The '8' shaped gasket is for the fuel transfer port between the injector cover and the Pod body. If that's missing you would have a very bad leak!

It seems odd that fuel would come from the shafts as there should be vacuum there, but one solution would be sealed stainless ball bearings on the shafts. This is how I do Crossfire TBs. The pic shows a mock up bearing for display purposes. The actual bearing is sealed on both sides with contact rubber seals:


Maybe the fuel is leaking from the pod and runing down the side and it just appears to be coming from the shafts.

 

It seems to come out right below...there is no squirting or bubbling that i can confirm it's out of the shaft...and it's not while i'm cranking (assuming vaccuum??), it's just when i stop cranking that a little dribbles from the base area...

there were 2 "8" shapped gaskets in the kit. A smaller one that fit on the trottle body no problem, and a bigger one. That is the one i haven't a clue where it goes and the instructions have no word of it.

All in all i don't think it's the shaft...and i know it's not leaking out of the bottom o-ring of the injector because then i'd at least be getting SOME fuel into the bores to start the engine...i'm getting no fuel, it's all bottling up in the TBI sumwhere and when i stop craking (assuming relieve vaccuum), it spills out from the base area of the TBI, towards the middle of the TBI if you were looking from front to back of the TBI...comes out the middle area there.

 

I didn't realize that you had no fuel from the injector.

You can pull of the injector plug and with allegator test leads and from a safe distance, use a common 9v battery to energize the injector. It will make a distinct click . if the pump is running, it will quirt . . .hence the safe distance.

This in my injector test/clean rig using a 9V battery to open the injector



If the pump is running, the injector opens and you get no fuel, then you may have a completely plugged fuel filter (unlikely) or there is something wrong in the TB. If you just rebuilt it, perhaps the diaphram is in upside down.

If you trip the injector with 9v and you do get squirt with the pump running, then logically you have an ECM or wiring issue.

Sorry I can't be more help.

 

i hope i don't have an ECM problem...this is my 2nd one i've gone through. I'm wondering if the diaphram was upside down...would it work at all??? As i said...it didn't work...then it did...now it doesn't...