joseph p

1989 L98 Coupe, tuned up a little over a year ago (7K miles +-) babied, but daily short run driver, ran fine til yesterday. Starts, idles fine, but if you give it gas it stutters, not hesitation but more like missing. It's got new( 1 year ago) wires, platinum+ plugs, new ign. module, cap, rotor,TPS set @ 56. Can't give it gas except if you feather it, even then it doesn't run "clear." Replaced the fuel pump 2 years ago, fuel filter, new injectors, one year ago.
Any educated guesses?
Thanks.

Chatman

Go through the simple things first. Especially plug wire connections.

mikey whipreck

I'm not sure... I'm sure someone will correct me if I'm wrong:
but isn't that a little low for a TPS setting?

seems like your symptons would indicate that is the problem (i.e. slow response from throttle)...

just a guess though...

joseph p

TPS setting is as per manual, besides it hasn't changed and it ran well for 1 year. Checked plug wires and connectors, they seemed fine but didn't have time to pull plug yet.
I'll keep trying. Thanks.

SunCr

Maybe the MAF or MAF Relays. Disconnect it (the MAF) and see if it runs any better.

jackdaroofer

I think I would hook up a fuel pressure gauge and test it under a load at acceleration

Just a thought

Fuel pumps can go bad and filters can get clogged. Company just biught me a brand nee ford 150 (UGH) and it stranded me twice with less than 100 miles on it, it was the fuel pump

seeya

Scott LeMuke

I had the same problem with my 1995. It was a hairline crack in the insulator part of spark plug number one. I put a new plug in and it ran like new.

weo89vette

Have you figured this one out yet? I've got the same problem on my '89. Started about a week ago, and I havn't had time to start troubleshooting. Hopefully this weekend. The only thing I can add is that the problem is worse when trying to accelerate up any incline. I too have new wires, plugs, rotor, and cap installed a month or so ago. I need to check the fuel pressure, and filter though.

Bruthish

Another vote for possible Fuel Pump....check the pressure and see what it is.....Mine ran but bogged everytime you tried to give it gas...it even started stalling at stop lights. So, it can still put fuel out, but less than is needed by your car.

information junkie

sounds like what mine is doing. my filter is new, so is the fuel pressure regulator. shop said that the fuel pressure is correct. if you get this figured out please tell. that will give me another direction to go with the troubleshooting.

weo89vette

ttt

John Robinson

Nobody with the problem said if they had just filled up with gas and this started to happen. I have had this in the past and found it to be a bad tank of gas. Car or Motorcycle would not run and could hardly maintain the speed limit. Sometimes putting a couple of cans of dry gas in helps but usually you will get really bad milage and as soon as you need a half tank or more of gas fill it up and drive it about 20miles and see if it clears up.