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'88 TBI Engine races -Edit- Fixed

Taylormade

Taylormade

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Started it up for the first time in a couple months and it makes a weird sound while cranking, almost like an out of control grinding.

Then it will fire up and the engine just races.

Any ideas?

Edit- I looked under the hood this morning (in the daylight) and found a vacuum line split in two going from the throttle body to what looks like to be some egr componet:dunno:

That is the first place ill start.
 
Last edited:
Well, I fixed the vacuum line but it didn't change a thing...

Now I'm stumped.
 
First: Does your check engine light work? If so scan for codes. Can you describe the grinding sound better? Was it only the first time you started it? How fast is the "racing"? I'm assuming it's like most with no tach... Does it stay constantly high at idle or will it drop down eventually? Is the motor hunting for idle or just a constant steady high idle. An unusually high idle CAN be caused by a vacuum leak, I had an internal leak at the intake manifold gasket that caused a high idle situation. Double check all the Vacuum lines as well as the base gasket for the throttle body. It's a good time to check all the connections to all the various sensors. I like to unplug and replug them while looking at the wiring itself. Check all the free stuff first. Maybe it's a bad connection or a bad ground somewhere. I will say, it seems like the worst thing you can do is let something sit, everytime I've let something sit, I seem to have problems.
 
It's really not a grinding now that I've heard it a few times. I think its just the sound of a cold engine being started at WOT.

Check engine light did not come on. It came on once 8 years ago...

It started up normal after a few times of racing so I let it idle for about 30 min and it started overheating....one thing after another.

Tomorrow ill replace the thermostat and see what Im in for next.
 
Check the throttle shaft. When I first brought my K5 home it idled high and the gas pedal was stiff. Turns out the PO had put an extra throttle return spring on it that didn't need to be there. I found the throttle shaft bushings were worn out and the throttle blades would hit the inside of the throttle bore before closing completely. This caused my high idle. You could get it to close by fiddling with it and would idle normal, until you stepped on the gas again. Ended up replacing the throttle body with a good used one.
 
I just had a thought, it's been sitting, any possibility the throttle cable or linkage is stick or hanging up? With the engine off can you have some one press and release the gas pedal and watch the linkage and plates move in the throttle body? It should be able to move with ease. I've had vehicles with cables that would bind or hang up, maybe the cables corroded and finally from sitting it got stuck open when you first tried to start it?
 
pull the air cleaner off, with the engine off, and check the throttle blades. if that isn't the issue, fire it up and spray around the base of the throttle body with some brake cleaner... i bet the idle dies down... voila, tbi base gasket blown out
 
Well, I figured out the problem.:woot:

While the blazer was getting a few upgrades these last couple months I put on a 1" body lift.....see where I'm going with this? The fan was hitting the lower shroud.:doah:

That explains the grinding noise and the racing sound. A little trimming and its back to normal. Looks like I need to get a tach, and read/search more on here.

I also replaced the thermostat and that resolved the overheating issues, I'm sure the fan not turning the one time I cranked it had a part in it also.
 
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