My 95 5.2L keeps running rough but its not every single time. I've read the TBS for spark plug routing and done that but it still runs rough, it sometimes hesitates on take offs and between 45-55 sometimes skips, it has new cap and rotor, new plug wires and the spark plugs are only a month old, I've checked the cap for ignition cross firing and moved the boots so that they ain't touching, it helped a lil bit but its still missing. I turned my throttle up just a hair to keep it from dying when I give it gas when its idling. Where is the air flow sensor located at so maybe I can check or replace it, I know ya'll get tired of seeing me post about the same problem but I'm trying to get it figured out, please help this is driving me crazy I need this truck running it is my only transportation

 

Speed/density system. Uses a MAP (manifold absolute pressure) sensor right on the front of the throttle body. There is a little 90* vacuum hose under there, they may have dried out, and cracked. Have a look.

How many miles on your truck? Has the plenum been fixed?

 

Quick question, when my computer went out it sit for a whole week with a completely full tank of gas, is there a chance that gas went bad in just a weeks time because I'm still on that tank and haven't put any in it yet. I use 87 from shell, I fill up once a week when I get paid and it last me till the next. The motor has roughly around 165,000 miles and I'm not sure about my plenum gasket, where is it located at? I will take a look at my MAP sensor

 

I doubt it's the gas. I've put green two stroke gas in my truck before and it didn't even notice.


Never waste gas fellas

 

lol

 

The 90* vacuum hose that you are talking about is it on the drivers side of the intake and have 2 different holes to plug it into? If so I had to put some tape on the boot end of it the other day the duct tape that the previous owner had wore out lol, me and my dad unplugged it and the motor would idle louder, its plugged into the top hole right now

 

Map sensor hose is small (3/4" long with a 90) and in front of the TB. One end plugs into the sensor, the other into the TB.


Fix all your vac hoses, and not with duct tape, sheesh.

 

Ok I found the map sensor hose directly under the map sensor. It looks good visually inspecting it without taking it off, its weird that it was running fine until I changed my computer, plug wires, cap & rotor and BAM!!

 

Think I would have a very close look at plug wires/firing order.

 

I checked the wires wire for cyl. #1 was pulled from the wire so I got a replacement from auto zone it ran fine for a day and acting the same way just not as bad but still doing the samething. I checked the dist. for ignition cross firing its good and my plugs are routed according to the tsb. I've read that the crank sensor on the transmission bellhousing could be causing this, does anybody think so? Even when I'm just going about 10 mph its got a jerking and when near 55mph high rpms and I have to let off the gas for it to shift sometimes. Is there a chance when I backfed the 12v back to the computer that I tripped a sensor or caused it to fail because it was running perfect before I fried the computer. I also reset the computer a few days ago by unhooking the neg. batt. terminal and turned my switch on like I was starting it and held it for 30 secs and then hooked the battery back up. I figured since it came from a junkyard it was a good idea to reset it after installing it on mine to clear out codes from the old truck