TPI Tuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
Sponsored by:
Sponsored by:

350 tpi falls flat on face at wot check engine light comes on

Thread Tools
 
Search this Thread
 
Old Mar 4, 2015 | 04:14 PM
  #1  
Towboater's Avatar
Thread Starter
Junior Member
 
Joined: Nov 2012
Posts: 18
Likes: 0
350 tpi falls flat on face at wot check engine light comes on

Hello, I've tried reading quit a few of the threads that envolve engines " falling on its face at WOT" and I'm still confused. Most of the posts talk about being to much or to little fuel amount and adjusting fuel pressure regulater, my car is a plane Jane stock 350 tpi I don't have all that fancy stuff can someone please help
Reply
Old Mar 4, 2015 | 04:35 PM
  #2  
Jonesyfxr's Avatar
Member
iTrader: (2)
 
Joined: Sep 2013
Posts: 345
Likes: 1
From: Buffalo, NY
Car: 85 Silver Iroc, 79 Camaro
Engine: LB9, 500+ ci BBC
Transmission: 700R4, th400 with brake
Axle/Gears: 3.42, hand made 40 spline 9"
Re: 350 tpi falls flat on face at wot check engine light comes on

Go get or rent a fuel pressure kit. Run the hose into window or where you can view while driving. Run it and watch the pressure. Most likely you may need a regulator or maybe the pump is failing.

It's a start.
Reply
Old Mar 4, 2015 | 04:37 PM
  #3  
Towboater's Avatar
Thread Starter
Junior Member
 
Joined: Nov 2012
Posts: 18
Likes: 0
Re: 350 tpi falls flat on face at wot check engine light comes on

Ok I'll try that, I checked to see how much pressure it had at the little stem on the fuel rail and it shot straight up and was hitting the bottom of the hood lol so I figured it was ok
Reply
Old Mar 4, 2015 | 04:51 PM
  #4  
someone972's Avatar
Senior Member
iTrader: (2)
 
Joined: Aug 2014
Posts: 575
Likes: 0
From: Fort Collins, CO
Car: 1991 Firebird Formula
Engine: 5.7L TPI
Transmission: 700r4
Axle/Gears: 3.23
Re: 350 tpi falls flat on face at wot check engine light comes on

What codes is it setting when the check engine light comes on? You can search the forum for how to pull them, all you need is to jump a terminal on the ALDL connector with a paperclip and it will blink the codes at you. They will be a great start at figuring out exactly what's going wrong.

EDIT: And I almost forgot to mention, even when the SES light turns off when you turn the car off and on, the code is still stored for you to retrieve.
Reply
Old Mar 4, 2015 | 10:01 PM
  #5  
Towboater's Avatar
Thread Starter
Junior Member
 
Joined: Nov 2012
Posts: 18
Likes: 0
Re: 350 tpi falls flat on face at wot check engine light comes on

Originally Posted by someone972
What codes is it setting when the check engine light comes on? You can search the forum for how to pull them, all you need is to jump a terminal on the ALDL connector with a paperclip and it will blink the codes at you. They will be a great start at figuring out exactly what's going wrong.

EDIT: And I almost forgot to mention, even when the SES light turns off when you turn the car off and on, the code is still stored for you to retrieve.
I tried that before and I recognized the normal code 12 and then it started the other code but I couldn't quite figure it out, all I know is it was blinking in a sequence of 3 flashes, I'll try it again tomorrow tho
Reply
Old Mar 5, 2015 | 10:26 AM
  #6  
irockid43's Avatar
Junior Member
 
Joined: Feb 2012
Posts: 77
Likes: 0
From: Spirit Lake, ID
Car: 86 IROC-Z
Engine: 355
Transmission: T5
Axle/Gears: 3.23
Re: 350 tpi falls flat on face at wot check engine light comes on

A fuel pressure gauge would be a great idea, but I would test it in park (you might find your problem there).

But first I would get a service manual at a parts store, check your codes, and go from there.

It sounds like you might have a code 33. Double check it and get back to us.
Good luck!
Reply
Old Mar 5, 2015 | 11:04 AM
  #7  
mantaguy's Avatar
Supreme Member
15 Year Member
Liked
Loved
Community Favorite
iTrader: (5)
 
Joined: Nov 2010
Posts: 5,892
Likes: 84
From: Mantua NJ
Car: 1 Owner 1986 TA with a WS6 package
Engine: 5.0 EFI
Transmission: THM700R4
Axle/Gears: 277 Posi Speedo
Re: 350 tpi falls flat on face at wot check engine light comes on

Originally Posted by Towboater
I tried that before and I recognized the normal code 12 and then it started the other code but I couldn't quite figure it out, all I know is it was blinking in a sequence of 3 flashes, I'll try it again tomorrow tho
Each code will blink 3 times,starting and ending with the 12 code
Reply
Old Mar 5, 2015 | 11:30 PM
  #8  
Towboater's Avatar
Thread Starter
Junior Member
 
Joined: Nov 2012
Posts: 18
Likes: 0
Re: 350 tpi falls flat on face at wot check engine light comes on

Well fellas car runs like a raped ape today... Took it down the road after work today to the part store. I bout me a fuel pressure tester and it's running 37 psi at idle, didn't get to take it on the road with the gauge hooked up tho to see what it did on the highway due to a pregnant wife that needed help lol. I'll be sure and run it tomorrow tho. One more quick question... I noticed when I shut the car off the pressure slowly drops till it gets to about 10 psi then it's stationary.... Is this a sign of leaking injector o rings perhaps??? Cause it seems if I drive it and shut it off for about 20 min and start it again it just don't hit when u turn the key like it's supposed to, takes about 3 to 4 seconds of cranking before it fires of.. But when it's cold from sitting overnight I can barely bump the key and it hits, thanks everyone
Reply
Old Mar 6, 2015 | 04:07 AM
  #9  
someone972's Avatar
Senior Member
iTrader: (2)
 
Joined: Aug 2014
Posts: 575
Likes: 0
From: Fort Collins, CO
Car: 1991 Firebird Formula
Engine: 5.7L TPI
Transmission: 700r4
Axle/Gears: 3.23
Re: 350 tpi falls flat on face at wot check engine light comes on

Unless you see/smell gas on the injectors, it wouldn't be leaking o-rings (at least not top side, you could still have vacuum leaks on the bottom). It could possibly be leaking injectors, but it could also be a leaking fuel-pressure regulator, or a bad check valve in the fuel pump. The way to figure out which it is would be to hook up the fuel pressure gauge, jump the fuel pump, and then clamp off the return or supply lines and see what happens. Be sure to stop the fuel pump from running as soon as you have your lines clamped off, you don't want to damage it by running it too long. If:
Supply + Return is clamped and it still falls: Leaky injectors.
Supply is clamped off and it doesn't fall anymore: Bad check valve in fuel pump.
Return is clamped off and it doesn't fall anymore: Leaking fuel pressure regulator.
Reply
Old Mar 8, 2015 | 10:23 PM
  #10  
Towboater's Avatar
Thread Starter
Junior Member
 
Joined: Nov 2012
Posts: 18
Likes: 0
Re: 350 tpi falls flat on face at wot check engine light comes on

Ok finally got a chance to tinker a little bit ran the code and its a code 48 for misfire diagnosis... My question is if it's a misfire.. Then why isn't it doing it all the time?? Why does it run fine again when I shut the key off and start the car again? Can somebody intrigue me on this?
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Wade787b
TPI
2
Sep 29, 2015 01:15 PM
Jae992
TBI
3
Aug 27, 2015 09:07 AM
bradleydeanuhl
DFI and ECM
4
Aug 12, 2015 11:48 AM
Omega
Interior Parts for Sale
2
Aug 10, 2015 12:46 PM




All times are GMT -5. The time now is 11:07 PM.