84stock

Hi,

Can you please give me advice. 1984, stock. was running fine. on the Ben Franklin bridge in philly, 60 mph, might well have well been in a 4x4 it was so rough. all of a sudden, it only has 1/8 throttle. stumbles if you push peddle past that. have to baby it to drive, slowest car on the road until we get to speed.

- no check engine light. seems smooth when idle/below 1/8 throttle

- pulled tank unit. pump seems secure. no obvious line leaks or cracks. hose & clamps seem ok. NAPA stock fuel pump & filter installed last year.

- no obvious fuel leaks.

- injectors prof rebuilt last year. engine was fine, just a little rough on cold start, once 180/warm its smooth/perfect. by far one of the faster 84's, last mechanic did some porting. just a daily driver for my son

- nothing obvious under the hood.

- not having expensive tools, what would you do to troubleshoot in order of easiest to hardest? (aka cheap first)

- guess a line could be partially clogged. but new filter and new pump last year, no idea how. paper element on pump looks good.

- I would check fuel pressure but don't have adapters or whatever is needed. cheap way to do it? Almost easier to buy a pump and just "see" (upgrade to 85 pump?)

- unrelated, this car has always been finicky at or below 1/4 tank fuel, "hard" turns and it would lose fuel pressure. straight hard power, no problem. plastic piece in fuel tank is there (assume to temp hold fuel in turns). but unsure if its not broken or incomplete. sender/pump really does look good. definetly think this is unrelated to my current dilemna. 1/2 tank gas, well above pump now. no way to leak check pump.

thanks for any advice.

Corvette40

Same thing happened to me while driving. I have an 88 with precats and one of them broke up and clogged the main cat.
You need to check your fuel pressure and there is no cheap way, you're going to have to buy the pressure gauge kit.

Red89'-L98

I had a car with a clogged catalytic converter and did that one time would not go more than 55mph and eventually would barely even want to run. Check to see if it is clogged, could very easily be your problem.

84stock

Thank you for responses! Can't be the catalytic converter. though brand new, the inside was hollowed out, nothing inside.

Red89'-L98

Well, that rules out one thing and I can not think of anything else at the moment of what it could be. Someone else with more knowledge than me should come along soon and be able to help you a lot more.

Good luck, hope you get it fixed soon.