limp mode and electronic throttle isues fixed for 4.8, 5.3, and 6.0 truck engines
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Teching In
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limp mode and electronic throttle isues fixed for 4.8, 5.3, and 6.0 truck engines So I had a problem with my wiring on my 5.3 engine swap and I searched and could not find any one who had posted the fix for this issue.
I just finished swapping a 5.3 into my 87 El Camino. Now the motor ran great for the first month that I had it installed even broke my record of a 14.0 at the track. But I then decided to dress up the engine bay a little so I started tucking wires behind covers and the fender Wells and such. Eventually I got it so most if not all the wires. Were hidden behind a cover or in Lome. Now here's where my problems began, I moved the battery to the bed just open up the engine bay and make room for the Turbo down the road. But after I finished hooking everything back up and started the engine it would not rev passed 1500 RPM. So that's when I started searching. I then learned that the particular motor that I have comes from the factory with something called abuse mode aka limp mode. So I figured that I must have pissed off the computer when I was hooking the battery back up. So I learned how to reset limp mode by cycling the key on and off 5 times which did reset the computer but only for a moment, it then went right back to the way it was before. That's when I decided to triple check my work. I had had problems with phantom problems do to bad grounds in the past so I checked my grounds and they looked good but I figured that had to be the culprate what I did was to make some ground straps that went directly from the negitave battery cable connected to the engine block and take them all out to where the ground wires were tied to the frame and body, and presto problem solved and I'm back to all 300 horses no studded and the electronic throttle is working like a champ. To all those new to wiring and efi. These computer's are very finockey and it doesn't take much at all to mess them up. You can never have too many ground straps bylut at minimum you should have one connecting one of the transmissions bellhousing bolts to the firewall, one connectine one of the bolts on the front of the motor and the frame, and lastly one connecting the frame to all the individual body pannels. The most important one being the ground connecting the trans to the firewall if you Domitian have one there the battery will ground through the transmission and you will burn up your front pump seal and blow trans fluid all over the place and most likely burn up your trans. Cherokee insurance is what I think.
Thanks for reading.
I just finished swapping a 5.3 into my 87 El Camino. Now the motor ran great for the first month that I had it installed even broke my record of a 14.0 at the track. But I then decided to dress up the engine bay a little so I started tucking wires behind covers and the fender Wells and such. Eventually I got it so most if not all the wires. Were hidden behind a cover or in Lome. Now here's where my problems began, I moved the battery to the bed just open up the engine bay and make room for the Turbo down the road. But after I finished hooking everything back up and started the engine it would not rev passed 1500 RPM. So that's when I started searching. I then learned that the particular motor that I have comes from the factory with something called abuse mode aka limp mode. So I figured that I must have pissed off the computer when I was hooking the battery back up. So I learned how to reset limp mode by cycling the key on and off 5 times which did reset the computer but only for a moment, it then went right back to the way it was before. That's when I decided to triple check my work. I had had problems with phantom problems do to bad grounds in the past so I checked my grounds and they looked good but I figured that had to be the culprate what I did was to make some ground straps that went directly from the negitave battery cable connected to the engine block and take them all out to where the ground wires were tied to the frame and body, and presto problem solved and I'm back to all 300 horses no studded and the electronic throttle is working like a champ. To all those new to wiring and efi. These computer's are very finockey and it doesn't take much at all to mess them up. You can never have too many ground straps bylut at minimum you should have one connecting one of the transmissions bellhousing bolts to the firewall, one connectine one of the bolts on the front of the motor and the frame, and lastly one connecting the frame to all the individual body pannels. The most important one being the ground connecting the trans to the firewall if you Domitian have one there the battery will ground through the transmission and you will burn up your front pump seal and blow trans fluid all over the place and most likely burn up your trans. Cherokee insurance is what I think.
Thanks for reading.
Last edited by racinea64; Dec 19, 2014 at 08:00 AM.