This is my first post in a long time, howdy! I will cut to the chase....
I recently placed a 1988 302 with fresh Trickflow Heads, Intake, and Lunati 51014 Cam (installed -4') 5 speed, etc... In a 1993 Ford Ranger Splash.
I am having horrible drivability problems. It is a Mass air, newer motorsport harness, A9L… It runs horrible when cold. You can hold the pedal at half throttle and it pops through the intake and does not rev for at least 5-7 seconds, just keeps popping. After 3-4 minutes of driving it clears out and drivers pretty good. Pretty smooth through the rpms, but does miss once or twice. At the same point, about 5 miles from my house it goes bizerk. I mean bad. It starts bucking, popping through the intake every time you let off the throttle and try to accelerate again. It does this at the same point in the trip every time. It is like a light switch.
However, if you press the pedal passed ½ or more it will run better, it misses once or twice, but nothing like what it does at light throttle. When I unplug the Mass air meter it runs sooo much worse. I mean, it can barely make it up the driveway. You can push the throttle to ¾ and it does not even rev, it just coughs and pops through the intake.
I pulled codes and got 91 41 O2’s lean, not switching and some thermactor (81 84 85) stuff and (nds) stuff. I unplugged the 02’s and still runs bad. I checked the wiring to the computer and I am getting continuity to the proper computer pins from the plugs at the exhaust. The o2’s look new but I had them lying around for a while. I am in the process of hooking up the Wideband O2 to see what is happening. I get a misfire from #4 when I put the timing light on that wire and drive it. Timing is at 12’ and advances nicely to 35-36 when you rev with the spout in… It also runs really bad when you pull the spout. It will barely drive until you almost floor it, and then it clears out and goes.
My question is, when the o2’s are unplugged and the mass air meter is unplugged what is causing the truck to run so poorly? It should be running off preset tables in the computer, right? I can press the throttle and it chokes and pops.
I have the egr propped half way open, still plugged in, Tps is Good, full sweep smoothly… I am going to check for the voltage at the computer plug when the truck is running for the o2’s, tps, maf, … I have switched out 2 computers, 2 maf, 2 TPS sensors, 2 set of plugs, 2 sets of plug wires, 2 distributor’s (MSD currently), 2 coils…etc
I just put in a 255 in tank pump, did it with the old pump also, fuel filter, even took the fuel rails off and cleaned the injectors/ changed the f/p reg...
I am going crazy here...
I recently placed a 1988 302 with fresh Trickflow Heads, Intake, and Lunati 51014 Cam (installed -4') 5 speed, etc... In a 1993 Ford Ranger Splash.
I am having horrible drivability problems. It is a Mass air, newer motorsport harness, A9L… It runs horrible when cold. You can hold the pedal at half throttle and it pops through the intake and does not rev for at least 5-7 seconds, just keeps popping. After 3-4 minutes of driving it clears out and drivers pretty good. Pretty smooth through the rpms, but does miss once or twice. At the same point, about 5 miles from my house it goes bizerk. I mean bad. It starts bucking, popping through the intake every time you let off the throttle and try to accelerate again. It does this at the same point in the trip every time. It is like a light switch.
However, if you press the pedal passed ½ or more it will run better, it misses once or twice, but nothing like what it does at light throttle. When I unplug the Mass air meter it runs sooo much worse. I mean, it can barely make it up the driveway. You can push the throttle to ¾ and it does not even rev, it just coughs and pops through the intake.
I pulled codes and got 91 41 O2’s lean, not switching and some thermactor (81 84 85) stuff and (nds) stuff. I unplugged the 02’s and still runs bad. I checked the wiring to the computer and I am getting continuity to the proper computer pins from the plugs at the exhaust. The o2’s look new but I had them lying around for a while. I am in the process of hooking up the Wideband O2 to see what is happening. I get a misfire from #4 when I put the timing light on that wire and drive it. Timing is at 12’ and advances nicely to 35-36 when you rev with the spout in… It also runs really bad when you pull the spout. It will barely drive until you almost floor it, and then it clears out and goes.
My question is, when the o2’s are unplugged and the mass air meter is unplugged what is causing the truck to run so poorly? It should be running off preset tables in the computer, right? I can press the throttle and it chokes and pops.
I have the egr propped half way open, still plugged in, Tps is Good, full sweep smoothly… I am going to check for the voltage at the computer plug when the truck is running for the o2’s, tps, maf, … I have switched out 2 computers, 2 maf, 2 TPS sensors, 2 set of plugs, 2 sets of plug wires, 2 distributor’s (MSD currently), 2 coils…etc
I just put in a 255 in tank pump, did it with the old pump also, fuel filter, even took the fuel rails off and cleaned the injectors/ changed the f/p reg...
I am going crazy here...