Register or Log In To remove these advertisements. |
|
|
|
Thread Tools | Display Modes |
03-18-2018, 01:41 AM | #1 |
Registered User
Join Date: Mar 2018
Location: Spokane
Posts: 6
|
1990 TBI acts like it's loading up like a carb
K so my 90 Suburban has an on and off again issue of sort of stalling out just off idle, and sometimes at speed in town.
It's a 4 bolt main 5.7. Stock. I recently bought it back from a friend who put the engine in while he had it. It was running way bad when I got it back, acting like the fuel filter was plugged. I went thru a few filters then replaced all the sensors on the tbi from stuff from the junkyard, air idle sensor, EGR, throttle position. Seemed to totally seemed to fix it. It's 99% better. But the off idle stumble is annoying. It is on 35 inch tires with somewhat tall gears. If I drive in 2nd gear in town it doesn't do the load up thing. Keeping the rpms up keeps it happier. Thoughts from the experts would be greatly appreciated. |
03-18-2018, 09:43 AM | #2 |
Registered User
Join Date: May 2004
Location: Minnesota
Posts: 4,620
|
Re: 1990 TBI acts like it's loading up like a carb
If it is loading up it could be running rich because of a bad coolant temp sensor.
There is testing information in post #11 of this thread: http://67-72chevytrucks.com/vboard/s...d.php?t=379142 That thread can be found be looking in the frequently asked question thread from the top of this board. http://67-72chevytrucks.com/vboard/s...d.php?t=445487
__________________
For those of you that are wondering why you are not getting replies to your thread: Did you give the model, year, engine, fuel system type, and transmission information? If it is modified from what came stock from the factory, let us know that too. |
03-18-2018, 12:49 PM | #3 |
Registered User
Join Date: Mar 2018
Location: Spokane
Posts: 6
|
Re: 1990 TBI acts like it's loading up like a carb
That's the one sensor I didn't replace cause it looked brand new when I got it. Tho I've noticed it has a slight leak at the thermostat housing; I suppose that could be allowing a bit of air there at the sensor once it's been running huh?
Ill test it today. Thanks! |
03-18-2018, 01:50 PM | #4 |
Registered User
Join Date: Apr 2011
Location: Klein Texas
Posts: 3,852
|
Re: 1990 TBI acts like it's loading up like a carb
This is where a good OBD1 scan tool is useful.
Where do you have your ignition timing set at?
__________________
My Classics: '72 K20 Suburban + '65 Dodge Town Wagon '72 Corvette Roadster +'67 Corvette Roadster '73 Z-28 Camaro '63 Ford SWB Uni Pickup '50 Ford Coupe |
03-18-2018, 08:08 PM | #5 |
Registered User
Join Date: Mar 2018
Location: Spokane
Posts: 6
|
Re: 1990 TBI acts like it's loading up like a carb
It never throws any codes. I jumped the plug and checked that way.
Haven't checked timing it runs awesome 99.99 % of the time so timings not the issue. I put a coolant sensor in today just to see if it did anything. Its hard to pin down cause it's so intermittent. But it's also not a big prob cause it's so intermittent lol.
__________________
You mess with the duck and you might get the bill! 1990 GMC Suburb 84 GMC half ton 1975 GMC 4x4 66 El Camino |
Bookmarks |
|
|