I have a 1980 Camaro(sorry if you like 3rd generation) and I put a 305 TPI in it from a 1987 Iroc Z. I bought a painless wiring harness, and bought the following new: fuel pump,rotor button, Mass airflow sensor, throttle position sensor, full tune up and everything I can think of. When it starts there is a loud sucking sound like the idle air control valve is messed up, BUT, when you try reving up all it does is pops, shoots FIRE from the turn downs (long tube headers and glass packs) and it bogs down and won't stay running. It acts like a dead spot or something like something cuts the engine off for about two seconds. I'm baffled so any helpful suggestions would be well appreciated.

 

whats your timing set at? sounds like it could be off to be popping when reving.

 

I don't have a clue. no matter which way the distributor cap is positioned it still does it. I drove it two miles and had to get it pulled back because it will idle but when you give it gas it dies It also smokes with bad gas fumes.

 

set the motor cylinder 1 to top dead center then setup the dizzy so that the rotor points to number 1 plug wire.. go from there

also check to see if your injectors are good. what sized injectors do you have? stock? any other mods to the motor? what ecm u running? what chip?

also make sure the o2 sensor is new

 

I already did the number 1 piston thing. The injectors are stock and the headers dont have o2 sensor plugs, so I dont have any. The engine did fine in the other car. Thats whats confusing me.

 

to run that ECM it needs an O2 sensor

 

But without it shouldnt it still be drivable?

 

ecm relies on the 02 sensor once the motor is warmed up to adjust for fuel and such. without it it has no idea whats going on. only at WOT will the ecm not use the o2 sensor

only other option is to force the ecm to stay in open loop in which it doesnt need the o2 sensor. that you will need a chip burnt for it and custom tuning for sure

i'd just get an o2 bung welded in and get a 24 dollar sensor i dont know about the painless harness but there should be an o2 sensor connection

 

There is one connector. Is that sufficient?

 

Sounds like a large vacuum leak. Is the PCV vacuum line connected to the intake? I forgot to connect mine once and it acted like you're described. It's kinda hard to see and thus easy to forget.

 

If thats the line on the top of the valve covers then yes it is hooked up. I'm thinking its the distributor. Does that sound like it may make it do that?

 

HOw did you set the engine baselines for air, fuel, and timing?

 

I put a new rotor button in the distributor and timed it by the # 1 piston being t.d.c. and put the dist. cap on, but I took it off later and the rotor button has been rubbing the cap. As for fuel... I used an MSD pump. Its pumping too much. Like 85 p.s.i. at 40 g.p.h. so that may be the problem along with the distributor???

 

The fuel press regulator should keep the press around 43 psi. Have you measured the fuel press?

The loud sucking sound is a dead giveaway there's a large vacuum leak and the other symptoms indicate a large vacuum leak as well.

"when you try reving up all it does is pops, shoots FIRE from the turn downs (long tube headers and glass packs) and it bogs down and won't stay running. It acts like a dead spot or something like something cuts the engine off for about two seconds.."

Check all the intake connections. Everything from the throttle body to the intake manifold. Check power brake line.

The pcv hose I was refering to connects the pcv valve (drivers side valve cover) to an intake port on the drivers side of the intake.

 

Ok. The sucking noise I think is the idle air control valve. I'll double check. The gas loads up real bad. Perhaps the pressure regulator needs to be replaced? I havent checked the pressure because I don't have the tools right now, but I will soon.

 

check all your intake, plenum, and runner gaskets too

 

Well its more like it loses ignition for a second then it comes back on. Does that make sense?

 

what timing cover and pointer are you using stock or aftermarket i had a aftermarket cover and pointer and my car was runnig pretty bad then i found out the aftermarket stuff is set up for 69 and earlier motors then in like 70 they moved the mark on the balancer and pointed 10 degrees and then in 85 they got moved to 45 degrees so TDC on the balancer should be almost straight up and the pointer should be up near there too my motor was off by that 45 degrees and after i adjusted it it ran like a raped ape till i found out i had already washed the cyl and was .060 over so the block was junk from running too rich for too long

 

I found the problem. The fuel pump I was using pumped way too much gas. It runs great now! The only problem is that it idles a little high and I have an oil leak when the engine warms up.