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All Messages in Thread | Author | Date |
4l80e not shifting right | Steve | 2-20-08 |
I have a 93 suburban 3/4 ton 4x4 454. I have an 4l80e that when it warms up (a mile or two) first gear won't work. 2nd and 3rd gears work perfect. OD will slip a few times then won't work. This is the weird thing. When the truck runs for a while (usually fwy) and we stop the truck and turn it off, it won't restart. Has to "cool" down for a hour or 2, then starts right back up and drive away. I have replaced the radiator and use a 160 thermistat (live in southern utah...gets hot here). I have replaced the ignition module, but what on the trans should i look at? | ||
Re: 4l80e not shifting right | BUBBA THE BUS TECH | 2-21-08 |
I am guessing two seperaate problems. If it won't crank hot it is generally a starter over heat. If it just won't start we need to look for failing or overheated electronic components. In both the starter and electronics for missing heat sheilding. Next we need to look for spark when it wont start, Injection etc. Cranking and not starting should show a code, if it won't you need to get a good scan tool and watch the sensor inputs etc while cranking. I have seen fuel pumps and fuel pump relays refuse to work after a hot soak. These would not show on the scan. Good Luck |