89 TBI problems. Running bad

89 4x4 350 with TBI First it started as small problem. Take off from a dead stop like a normal driver would and you do OK. If you are at any cruisen speed and try to accelerate over half throttle motor would start to cough a bit and not want to accelerate under hard load. Running this way for awhile. So up at about 3k RPM it wont let you accelerate smothly but you can ease your way to 60mph or so.

By the way this is a truck I am close to buying. He drives by my house daily and it sounds good going by.

He came home tonight and shut truck off. When restarting hot it hesitates and he actually had to hit the pedal to start it. Almost seems to be running rich. I took off the air cleaner to see how injectors were spraying. When we gave some gas it backfired (big flame) through throttle body high enough to hit the hood. He said it has been running real "doggie" a pooch I guess. My guess is a problem is progressing and I want to know what it is before I buy. I had a Camaro 1991 with a 305 TBI that started doing the exact same thing with the cutting out like it was losing spark under any hard load. Cant really say for sure I never had this problem.

He just replaced the cap rotor and wires. And no improvement.

It also has an exhaust leak at the manifold/head under first port that you can hear but cant see. Arent the factory manifolds gasket free? I couldnt imagine it beeing anything else.

Any opinions

Some more important details

When truck is in nuetral (park) it will rev up fine. Vroom vrooooom Vroooooom

Only when driving will it (except for that one time) start kicking spitting or what ever the hell it does. Its not my truck yet so I cant start trouble shooting. Was suppose to buy it tonight but he need a way to work tomorrow.

Sounds like a spark problem. I know all of it has replaced, but what if there is a bad plug, or a grounded wire. Also... how is the timing?

change the fule filter!!!!! I had the same problem w/ my 94 SUV I did every thing from plugs wires time and my mechanic told me to change the Fule Filter !!!

Bought the truck tonight. 89 4x4 350 TBI. NO RUST (reason I bought it) $1400

It cuts out under load. Sometimes when I am accelerating at about 40 and I let off a little on the gas it will actually PICK UP speed.

If I accelerate hard and let off it will back fire but not all the time.

I get to trouble shoot now. Yippeeee Owell atleast its a Chevy.

But I am still looking for opinions.

I think he said he did change the fuel filter. But I plan on checking the EGR valve, coil and pick up coil and I will probably add a new fuel filter when I am at it. A fuel filter is one thing I do right away when buying a used car.

DISTIBUTOR hold down clamp was loose. Checked the timing the morning after I bought it and it was way off. A little adjustment and it runs great. And paid for.

You did good, TopDog!!

Thats sweet! Thought that might have been it. Had the same problem in a truck of mine once. Right on

Good to hear man glad to hear there are some other people that got a good deal on an old workhorse. I got my 89 C1500 for $250.oo and had to put a new driveshaft in ($125.00) P.S. if you ever need a used driveshaft dont bother looking on the East Coast I checked every junk yard I think I got the last one .

Good to hear man glad to hear there are some other people that got a good deal on an old workhorse. I got my 89 C1500 for $250.oo and had to put a new driveshaft in ($125.00) P.S. if you ever need a used driveshaft dont bother looking on the East Coast I checked every junk yard I think I got the last one .

P.S. 218,000 on orig. motor, tranny. My motto "if it dont leak and burn oil it aint a chevy"

I recently bought a 93 ck 2500 with 478,000 miles on it, was excuvation company truck original motor believe it or not clean truck, truck misses and is sluggish and sometimes stalls at takeoff. I replaced cap/roter plugs/wires and made sure firing order was correct, new fuel fiilter ran a code test and 32 came up so I unpluged vac.hose from the egr and it died,I have made sure silanoidconected propably, it is. I replaced all vac. hoses and tested. I even checked fuses. I don't know how to tell if the egr silanoid is bad and I don't know where the t/b wire is. I have a few more things to try but still looking for suggestions.