1990z28

Ok well I got a 90 305 TBI gaskets went bad and I replaced them and now the bottom one is still leaking and I have a spacer so theres to. I can see gas puddle up on the gasket and spacer a bit. It will start up but die out. If you kick the throttle it will stay tell it get down to low RPM. And I kicked it a few times and fire shot out of the TB twice. I dont know if something else is screwed up along with the gasket there both new and one wont seal. Please some one help me. Right now I cant get it in the garage because of my truck and the camaro is up by the garage so I cant push the truck out and move it. I dont know what to do. I got most of the stuff to go carb from my truck since I am restomoding it I have a High rise intake a Edelbrock 650 I would just need to get a return style regulator. Is that my only choice or should I try to fix my TBI and hopefully not pull my hair out as I do it.

camaronewbie

What gaskets did you replace?

Backfiring - check firing order, make sure all plug wires are on securely (they should 'snap' on), make sure no plug wires are burnt, test continuity and make sure no resistance on any plug wires, check timing.

1990z28

The TB base gaskets and the plugs and wires are okay. And the timing was set at 0 base timing.

camaronewbie

Most backfiring issues that I've seen have been ignition related, that's why I mentioned the wires, etc. "wires are fine" means that you've checked them for continuity? Even if they are brand new $10,000 wires, one or more could have a break/short in it - I've bought plenty of brand new bad plug wires in my life.

I've also seen many times where a plug wire won't stay on the plug or cap - it wiggles off, and the plug end has to be slightly pinched tighter to keep it on - that will cause backfiring.

As far as the gasket goes - you cleaned the old gasket material off the TB and the intake really well and scraped both with a razor blade, used gasket maker when installing, and torqued the 3 bolts to spec? If it's not sealing, it's going to have to be redone. Are you getting decently sized gaskets? Some come really thin, others are thicker sometimes and seal better. All surfaces must be dry and very clean. I also wipe one last time with brake cleaner and cloth before doing gaskets - brake cleaner evaporates quick and leaves no residue.

1990z28

Yes I have checked my wires I may throw my truck set on it, the gaskets started not sealing with the ones that were on it I pulled them and they still looked good no cracking or pieces missing so I dont know if heat got to it. The new ones came from Carquest there thick and good and I cleaned the surface the one that is on to of the spacer sealed the one on the bottom dident idk if the spacer warped it dident look like it and its a 1 inch spacer. might be 1 and a half. It started doing it a few days ago so I replaced the gasket thinking I just blew the gasket but I am now thinking it may be heat related since it has gotten up high and humid here. If something is screwed I might throw a carb on it and go from there I have a high rise but I dont know how well it will fit under the hood. I just dont like the TBI.

alexisgreene

The fire coming out is not TBI related. Your engine is either misfiring, or you have a gasket leak between cylinders. I would put money on a blown gasket since the power loss you described is another symptom. Use a cylinder pressure tester and see what happens.

1990z28

The TBI gaskets are my problem when I hit the gas to keep it going you can hear the vacuum leak from it and the base of it you can see it getting wet. When the vacuum in the TBI isent working it wont pull the gas in like it should and thats my problem why I am losing the power. And it doesnt shoot fire every time it was very rarely. But my bottom gasket inbetween the spacer and the intake is not sealing at all its like something is warped thats the problem the one I pulled off had to its just in one area that it wont seal when I pulled off the old on I had to break it free since it did seal. It just started acting up a few weeks ago the engine ran fine before that vacuum leak.

alexisgreene

If you think that is the problem, remove the spacer, clean intake and TBI surfaces, install new gasket and you should be fine. Why continue to use the spacer if it is the source of your leak?

As for the flames, again, check for ignition problems or head gasket problems. Flames will only come out your throttle body if the intake charge is exposed to a flame... which should NEVER happen. Once every now and then is NOT acceptable.

1990z28

The TBI gaskets are my problem when I hit the gas to keep it going you can hear the vacuum leak from it and the base of it you can see it getting wet. When the vacuum in the TBI isent working it wont pull the gas in like it should and thats my problem why I am losing the power. And it doesnt shoot fire every time it was very rarely. But my bottom gasket inbetween the spacer and the intake is not sealing at all its like something is warped thats the problem the one I pulled off had to its just in one area that it wont seal when I pulled off the old on I had to break it free since it did seal. It just started acting up a few weeks ago the engine ran fine before that vacuum leak.

camaronewbie

I agree - get rid of the spacer - if you've got stock heads and intake, the spacer is giving you nothing anyway.