Mike89Suburban
Junior Member
- Joined
- Jul 16, 2015
- Posts
- 5
- Reaction score
- 1
- Location
- NY
- First Name
- Mike
- Truck Year
- 1989
- Truck Model
- 1500
- Engine Size
- 5.7
This is a little long winded -sorry. I am also not a professional mechanic. I recently purchased a 1989 Chevy Suburban 350 with 33,000 original miles. It was last registered six years ago. When I bought it, it was on jack stands and had an inch of dust on it. Full tank of old gas too. The previous owner said before he put it up on jack stands he did a full and complete tune up. After going through the basics, inflating the tires and charging the battery, it started right up and a/c blows cold air. I drove it 150 miles to my home. On the way home it stalled a few times when stopping at lights or to pay tolls, but started right back up every time. I’ve been driving it around town. Put about 300+ miles on it - ran through the old gas. When in drive or reverse with my foot on the brake, the truck would stall, but would idle smooth in park or neutral. At lights if I put it in neutral it would be fine. The truck ran awesome (expect for the stalling issue). Transmission shifts perfectly. There are no pending codes and the check engine light is not on.
I tried cleaning the TBI with injector cleaner, while the TBI was attached to the intake manifold - no real help. I changed the fuel filter - the fuel filter was not blocked ,but nasty stuff dripped out of it. Changing the fuel filter had no real effect.
I read a bunch of threads on the net about the stalling problem while in gear - seems like a common problem with no great solution. I changed the IAC - there was a slight improvement. After changing the IAC it took a few more seconds, when in gear, before it would stall. I changed the EGR and PCV - which had no real effect. I changed the coolant temp sensor - also no effect.
The next thing seemed to be the fuel pressure regulator. The kit for the pressure regulator and the entire TBI rebuild kit with a new pressure regulator was a nominal price difference, so I figured I might as well get the rebuild kit. I disconnected the TBI from the intake manifold. The gasket between the TBI and the intake manifold seemed to have been squished into the underside of the TBI into the channels/canals that lead to various vacuum lines. Parts of the TBI were pretty dirty. It was pretty black where the IAC goes into the TBI. The vacuum lines seemed pretty dirty, but nothing was blocked by any means. I cleaned the TBI with throttle body cleaner and followed the instructions and did the rebuild (and changed the pressure regulator). It was not overly complicated. I don’t see how I did anything wrong.
When I put the TBI back on the intake manifold, reconnected everything and started up the truck it idled really high and steady and never dropped down. My guess is it is at like 2500+ rmp. Any thoughts??? I would like to first find out what may be going on with the TBI and if I did something wrong in the rebuild. Also the check engine light is not on and no codes are pending.
I tried cleaning the TBI with injector cleaner, while the TBI was attached to the intake manifold - no real help. I changed the fuel filter - the fuel filter was not blocked ,but nasty stuff dripped out of it. Changing the fuel filter had no real effect.
I read a bunch of threads on the net about the stalling problem while in gear - seems like a common problem with no great solution. I changed the IAC - there was a slight improvement. After changing the IAC it took a few more seconds, when in gear, before it would stall. I changed the EGR and PCV - which had no real effect. I changed the coolant temp sensor - also no effect.
The next thing seemed to be the fuel pressure regulator. The kit for the pressure regulator and the entire TBI rebuild kit with a new pressure regulator was a nominal price difference, so I figured I might as well get the rebuild kit. I disconnected the TBI from the intake manifold. The gasket between the TBI and the intake manifold seemed to have been squished into the underside of the TBI into the channels/canals that lead to various vacuum lines. Parts of the TBI were pretty dirty. It was pretty black where the IAC goes into the TBI. The vacuum lines seemed pretty dirty, but nothing was blocked by any means. I cleaned the TBI with throttle body cleaner and followed the instructions and did the rebuild (and changed the pressure regulator). It was not overly complicated. I don’t see how I did anything wrong.
When I put the TBI back on the intake manifold, reconnected everything and started up the truck it idled really high and steady and never dropped down. My guess is it is at like 2500+ rmp. Any thoughts??? I would like to first find out what may be going on with the TBI and if I did something wrong in the rebuild. Also the check engine light is not on and no codes are pending.
