1989 Camaro RS auto 5.0 v8
Lately my throttle response has gone to crap and I'm not certain why. When I press the gas in there is a very noticeable delay, sometimes long like 10 seconds before any real acceleration begins. I find I have to give it a quick push sometimes to get any response out of it, rather than a gradual increase.

When at freeway speeds and I gun it, it doesn't accelerate smoothly at all. The RPMs will increase but there is a throttle lag and my speed doesn't increase noticeably, then there will be a small and sudden burst of speed/lurches forward.

Then lag where it feels like it's being held back, then burst of speed and this repeats until it's at speed. It's hard to explain the feeling between the bursts of speed, like revving too high in a low gear and not getting the power you would in a higher gear.

I've ran it for a week with 93 octane fuel and sea foam mix in the gas tank but it didn't help any. I'm planning to replace the fuel filter this weekend hoping that will do it, any other things it could be? Clogged fuel lines(i hope not)?

 

Try checking your fuel pressure.
If I'm not mistaken I think that car would be TBI. If so, I think the pressure is supposed to be something like 12-13psi. If possible, try rigging up the gauge so you can watch it while driving. See if pressure is dropping off when the problem is occurring.

If this is MPFI/TPI, then the pressure should be about 42psi key on engine off, and in the high 30s with engine idling. On that system, the pressure is referenced against manifold vacuum.

 

Yeah it's a 305 TBI. I have no idea how to go about checking the fuel pressure though, I've never done that before. I understand you can rent the equipment but I wouldn't know where to go from there. Is it relatively easy?

Also, I noticed this after a second test today. After I gun it on the freeway once I exit and come to a light the engine stalls out on me and it runs very rough after starting it back up.

I get no real acceleration when doing this, you'd think I was trying to go 5mph faster on the freeway by the way it accelerates, yet RPM's shoot up. Sometimes RPM's bounce up and down when trying to accelerate to passing speeds as well.

I have a suspicion something is clogged, what do you think?

 

Cfm tech . Com has a fuel pressure adapter and gauge that mounts between the existing fuel inlet line and the throttle body ... theyaint cheap though ..70-80$ with gauge I think .... IMO its a nessesity to have a fuel pressure gauge ..... if pressure is low then change filter if still low time for fuel pump ... psi should b 13-14 if possible and slightly higher if u have modded anything ...

91' firebird .. 305 TBI .030 over , balanced bottom end , speed pro hyper flattops , 10.6:1 CR , all ARP rod bolts and main studs , melling HV oil pump , trick flow super 23 175cc heads, Howards HR 214/218@.050 .488/.495 lift on 114 LSA , full roller 1.6 RR = .520/.528 lift , summit dual plane intake port matched , shorty headers into 2.5" Y w full 3" flow master system and 3" cutout in front of axle , msd billet dizzy, 620cfm TBI , custom CAI , tubular adjustabke LCA pan hard , umi torque arm wonder bar , BMR trans cross member , COMP engineering SFC's, disc rear w 4.10's, drilled an slotted rotors, EBL flash , VRFPR, WBO2,

 

Is it downshifting? Or are the RPMs just shooting up while staying in the same gear? Because it sounds like your transmission could be slipping.

I've heard they have a cheap fuel pressure gauge at Harbor Freight, but I don't know if there's any problems with it.