I recently bought a 1988 Chevy suburban non running. Has 350 tbi motor. Owner was pretty sure fuel pump went bad on her. Truck has set for probably 5 years. I did replace fuel pump and it did start. Since then I have also replaced fuel filter, injectors (had to, old ones did not work and would not start until I did), drained old gas. I had driven it around my house but never over 35 or 40mph. Friday I got the tags on it and took it for its maiden trip on the highway. Starts fine and idles good. But at highway speeds it has a miss or hesitation. I then put full tuneup on it. I had also rebuilt TBI when I changed injectors. This made no difference. What did make a difference was not putting truck in OD but rather just in Drive. No hesitation then or missing. If I went to OD then it would run funny again. Acts like you are braking and then letting off while giving gas. Or like running out of gas and then picking it up again. Trans is I think an R4 and has been rebuilt once before. Could it need filter change or new fluid? Is ther maybe bad sensor? Where might I start? No check engine lights.
tranny or engine trouble?
- Thread starter jocressm
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zora
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Since it sat for 5 years I would start with a change of filter and trani fluid. It also could be related to the lockup torque convertor since you say the problem goes away in drive. I know you have no light but did you try checking the computer for stored codes?
Once again, Zora has made great suggestions. IF you can find the torque converter lock up switch, just unplug it and see if that makes a difference. If so, it's either that or perhaps the fluid and filter change will help it. I'd change the fluid and filter first and if it persists, unplug the tq lockup switch.
VanGo
New member
could be a bad miss under load. Running in OD loads up the engine more than D does. When you said you did a full tune-up did you change plug wires and cap?
Yes, put complete tuneup on it. It will struggle for 3 or 4 seconds at highway speed and then pick back up for 5 or 6 seconds and then start the cycle over. Starts and idles great. Seems to accelerate good. Just does not cruise well in OD.
VanGo
New member
Okay. I'd look to the trans then. After sitting that long there may be some crud in there. A fluid and filter change would be wise. There are some trans flush additives that might work, or you might just get it flushed at a shop. They are supposed to change the filter when they do one.