Hot Rod Forum : Hotrodders Bulletin Board

Hot Rod Forum : Hotrodders Bulletin Board (http://www.hotrodders.com/forum/)
-   Modern Electronic Engines (http://www.hotrodders.com/forum/modern-electronic-engines/)
-   -   89 tbi 5.7 running poorly no power at low rpm or half throttle (http://www.hotrodders.com/forum/89-tbi-5-7-running-poorly-no-power-low-rpm-216440.html)

monsterchevy355 03-10-2012 12:29 PM

89 tbi 5.7 running poorly no power at low rpm or half throttle
 
iv got an 89 fullsize chevy with a 5.7 tbi and 5speed with ceramic clutch. Its been runnin like complete **** latley and im stumped of figuring it out. Started pullin my hair out yesterday after if left me walking twice in 1 hr and seriously thinkin bout throwin the tbi and intake away for a carb. its thowing several codes a 12 15 33 34 32 The motor is a reman replacement and idk how to find out if its still under warrenty. It is real doggy around 1 to 2.5 grand and seems like its got a dead spot in throttle. runnin down highway it will stall out and stay stalled untill i take my foot off gas then its fine untill i push petal halfway it will stall again like i shut the key off. Also at the same time it stalls my tach will stick and my temp guage goes crazy. I apriciate any help anyone can give me. If there is anything else you need to know ill glady post

LATECH 03-10-2012 03:09 PM

The tach and fuel gauge sound like a ground wire problem.
The running problem sounds like a fuel pump. It too could be a ground problem. Need to check over your grounds, there should be at least 4.
One from battery to engine, will be large batt cable. One from negative post to rad support. One from engine to firewall.Also it should have one from engine or body to the frame, prefferably from the engine to frame, as the fuel pump grounds through the frame.
If all checks out, perform a fuel pump pressure test.
It probably wont have a test port for PSI test, so you will need to rig something up. You also will need a good gauge that reads small pressure, like 20 pounds on at least a 180 degree sweep.The TBI runs about 13 pounds. Using a gauge that reads say 60 pounds wont give an accurate assesment as the scale is too big.Hence the 20 psi range. If the pressure drops to 7 or8 ponds, it wont be easy to tell if the gauge reads a scale that is too large.

monsterchevy355 03-10-2012 03:20 PM

I just checked fuel pressure an hour or so ago and it reads bout 12 or 13lbs. I got to messin with the temp sensor plug and i think thats been my problem all along. I unplug it and it runs like a dream. gobs of power, good throttle response and no hessitation. also unhooked batt and cleared computer now its throwing code 22. As of right now iv got an old temp sensor pluging the hole and have the one i pulled out laying on intake with it pluged in and the truck runs perfect. I unplug it it still runs fine. Plug it in to the other one plugging the hole it idles way down, becomes doggy and hessitant and no power. Same way if i swap sensors and plug it in it runs like **** but if i unhook it its night and day difference.

monsterchevy355 03-10-2012 08:25 PM

I figered it out. damn tps had short. put another used one on n goin strong again


All times are GMT -6. The time now is 12:17 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.