91 350TPI 700r4, Speed Density harness. and the 350 has about 13k miles on a rebuild
Recently changed the fuel pump, fuel lines, fuel filter. And the ignition modual sensor in the distributor.

Here is what is happening.
The car runs fine when I first start it and when I first drive it. After about ten minutes the car starts to bog out. It will idle fine but wants to bog out when i hit the gas. So when I try to increase speed after ten minutes of driving(sometimes less) the car doesnt go! I dont really know how to explain it. But it wants to die or something and then I take my foot off the gas and its fine until I press the gas again. Weird thing is I can pull over.. shut the car off and turn it back on. The car runs PERFECT again for that ten minutes. I tried upping the fuel pressure to 46 at the rail and it did not make any changes.(i have a holley afpr)
I did take a data log with datamaster 8D v351 but i dont really know what im looking for.

hopefully someone has some type of suggestion! i only have a few weeks before first snowfall

 

anyone have any idea?

 

I am kind of having the same issue with my '89 Iroc. Except mine is continously running rich. After the car warms up it starts to want to bog down. I too have replaced my fuel filter, and now I am working on my EGR valve. Also been told it could be my injectors. By turning the car on and off it may reset your ECM, hence the issue recurring. Are you getting any Check Engines lights?

 

nope no check engine lights

 

ttt

 

cat plugging?

 

Ohm the injectors warm.

 

What is the fuel pressure WHILE IT'S SCREWING UP? (as opposed to, while it's sitting in the driveway idling)

Duct tape your gauge to the windshield, drive around, make it do its thing, get a reading WHILE IT'S SCREWING UP.

 

cats not plugging.. its not even a month old along with the exhaust.. i checked the timing and it was set to 0* and after some research a stock 350 is supposed to be at 6*.. I did have knock count at 4 when it was at 0* and i put it to 6* and i had 2 knock count.. and now i lowered it to around 4 and i think the knock count is gone. going to test drive it now and see whats up and get back to you guys after.
ill try the fuel pressure thing too

 

fixing the timing made the car run 100% better! just a hair of boggin out but nothing really noticeable.. have to play with the timing a little more and the adjustable holley afpr. anyone know what the afpr is supposed to be at in datalog? mine goes up to 15.5 and starts at like 14.75

 

Tom...put it to 6* and leave it there!!

 

even though its givin me 2 knock counts?

 

Sorry I know this is a really stupid question, but I am fairly new to this and wanting to know practically all that I can about my car.....what is a knock count? Thank you.

 

There's No fuel pressure sensor for datalogging.
TPI should be about 42psi with the engine off and after the first pump cycle and should drop to between 32 and 38psi more or less at idle.