LT1-LT4 Modifications 1993-97 Gen II Small Block V8

24x hell

Thread Tools
 
Search this Thread
 
Old 09-17-2011, 07:56 AM
  #41  
Launching!
iTrader: (2)
 
RGSS's Avatar
 
Join Date: Apr 2007
Posts: 278
Received 5 Likes on 5 Posts

Default

Got it tuned, it ran OK, but was plauged with issues from the start, like we couldn't get the TPS to zero out. It ran like garbage when cold.

Then when I drove it PA this summer is when it started running like garbage all the time.
So this backfiring and acceleration problem has not been there all the time? It started after a trip to PA this summer?
Just trying to get the whole picture here.

A misfiring cylinder pumping air into the exhaust will cause a false lean condition for that bank and PCM will try to compensate adding more fuel on the same side.

Make sure all your coils and plugs are firing
Old 09-17-2011, 01:47 PM
  #42  
TECH Junkie
Thread Starter
iTrader: (22)
 
camar0corey's Avatar
 
Join Date: May 2006
Location: Spring Hill, FL
Posts: 3,975
Likes: 0
Received 2 Likes on 2 Posts

Default

Is there a way to read out the coils? I could read the wires out, I suppose I should have done that yesterday when I did plugs.

Well its never ran right under 20% throttle, just that in the last two months it been worse.
Old 09-21-2011, 11:03 AM
  #43  
TECH Junkie
Thread Starter
iTrader: (22)
 
camar0corey's Avatar
 
Join Date: May 2006
Location: Spring Hill, FL
Posts: 3,975
Likes: 0
Received 2 Likes on 2 Posts

Default

Great! Now what the hell is wrong with this thing? I went out, turned fuel trims off as recommended, loaded the tune. No errors. Go to start the car, it cranks maybe a second then nothing, turn the key again still nothing??? WTF?! So now it won't run at all?
Old 09-21-2011, 11:47 AM
  #44  
TECH Junkie
Thread Starter
iTrader: (22)
 
camar0corey's Avatar
 
Join Date: May 2006
Location: Spring Hill, FL
Posts: 3,975
Likes: 0
Received 2 Likes on 2 Posts

Default

More info: ses light is slowly flashing, fuel pump is not shutting off after initial prime. Car doesn't even attempt to start, battery is good but it reminds me of when you have a dead battery, you turn the key to crank and nothing happens.

How the hell did I go from a car that ran like *** to not running at all? This isn't good, I have class tomorrow!
Old 09-21-2011, 11:59 AM
  #45  
TECH Addict
iTrader: (14)
 
GR33N GoblinM6's Avatar
 
Join Date: Jan 2005
Location: Utah
Posts: 2,301
Likes: 0
Received 1 Like on 1 Post

Default

did you blow a fuse? or the starter solenoid might have blown
Old 09-21-2011, 12:03 PM
  #46  
TECH Fanatic
iTrader: (2)
 
draggin97s10's Avatar
 
Join Date: Mar 2009
Posts: 1,471
Likes: 0
Received 0 Likes on 0 Posts

Default

hydra-locked because of a stuck injector and running fuel pump? take the plugs out and try and crank it. Check ignition fuse like above stated!
Old 09-21-2011, 01:30 PM
  #47  
TECH Junkie
Thread Starter
iTrader: (22)
 
camar0corey's Avatar
 
Join Date: May 2006
Location: Spring Hill, FL
Posts: 3,975
Likes: 0
Received 2 Likes on 2 Posts

Default

The injectors should be good, they only have two weeks of run time on them, brand new injectors I put in before I made this thread. Hell it is what prompted me to make this thread. I had removed ones I thought troubleshooting had shown to be bad.

Battery is a optima red top, multimeter shows 12.42 volts. Checked the fuses, no burned out fuses.

Starter is a Duralast, I swapped it out Friday. I suppose it could be dead, but damn what are the odds? I suppose I will have to pull it and get it tested to rule it out. I swapped it out Friday as the body split!
Old 09-21-2011, 01:46 PM
  #48  
TECH Fanatic
iTrader: (11)
 
merim123's Avatar
 
Join Date: Oct 2005
Location: Chitown, IL
Posts: 1,892
Received 17 Likes on 15 Posts

Default

you're not getting any crank at all? or it will crank but not fire?
Old 09-21-2011, 01:55 PM
  #49  
TECH Junkie
Thread Starter
iTrader: (22)
 
camar0corey's Avatar
 
Join Date: May 2006
Location: Spring Hill, FL
Posts: 3,975
Likes: 0
Received 2 Likes on 2 Posts

Default

Won't crank at all. When I turn the key its like the starter thinks about working and then poof! Nothing. About to pull the 5 day old starter, both it and the redtop will be making a trip to Autozone.

Can a battery show volts but then when asked to provide the juice just fall on its face?
If its neither of these I don't know where to go next.

I don't understand how a car could run, but not good, then I reload the previous tune and then the car won't crank? PCM test says the PCM is fine also.
Old 09-21-2011, 02:10 PM
  #50  
TECH Fanatic
 
05HD's Avatar
 
Join Date: Feb 2006
Location: CT/NJ
Posts: 1,025
Likes: 0
Received 1 Like on 1 Post

Default

Originally Posted by camar0corey
Won't crank at all. When I turn the key its like the starter thinks about working and then poof! Nothing. About to pull the 5 day old starter, both it and the redtop will be making a trip to Autozone.

Can a battery show volts but then when asked to provide the juice just fall on its face?
If its neither of these I don't know where to go next.

I don't understand how a car could run, but not good, then I reload the previous tune and then the car won't crank? PCM test says the PCM is fine also.
I would see if the engine turns by hand before you pull stuff off and go to the parts store.

The fuel pump not shutting off would lead me towards a PCM problem. Maybe it went bonkers and opened all the injectors and left the pump on = hydrolocked on gas.
Old 09-21-2011, 02:17 PM
  #51  
TECH Fanatic
iTrader: (11)
 
merim123's Avatar
 
Join Date: Oct 2005
Location: Chitown, IL
Posts: 1,892
Received 17 Likes on 15 Posts

Default

Originally Posted by camar0corey
Won't crank at all. When I turn the key its like the starter thinks about working and then poof! Nothing. About to pull the 5 day old starter, both it and the redtop will be making a trip to Autozone.

Can a battery show volts but then when asked to provide the juice just fall on its face?
If its neither of these I don't know where to go next.

I don't understand how a car could run, but not good, then I reload the previous tune and then the car won't crank? PCM test says the PCM is fine also.
yes it can. if it's a redtop and you are checking on the top terminals it may be fine. BUT - make sure the ground and power are attached very tightly on the side terminals.
Old 09-21-2011, 02:22 PM
  #52  
TECH Fanatic
iTrader: (2)
 
draggin97s10's Avatar
 
Join Date: Mar 2009
Posts: 1,471
Likes: 0
Received 0 Likes on 0 Posts

Default

You have to do a load test to tell if a battery is actually good......im still betting on hydra locked
Old 09-21-2011, 03:31 PM
  #53  
TECH Junkie
Thread Starter
iTrader: (22)
 
camar0corey's Avatar
 
Join Date: May 2006
Location: Spring Hill, FL
Posts: 3,975
Likes: 0
Received 2 Likes on 2 Posts

Default

Starter and battery both tested good, have a PCM on order.

Now the big question, could some things have been bad in this PCM from the get go? This thing has never been right since November, just go through phases of running decent and phases of running like garbage.
Old 09-21-2011, 03:53 PM
  #54  
Teching In
 
cj56's Avatar
 
Join Date: Sep 2010
Posts: 17
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by draggin97s10
hydra-locked because of a stuck injector and running fuel pump? take the plugs out and try and crank it. Check ignition fuse like above stated!
this

cars running too rich
fuel pump constantly running
hard to start

check your oil and see if it smells like gas
Old 09-21-2011, 03:58 PM
  #55  
TECH Fanatic
iTrader: (2)
 
draggin97s10's Avatar
 
Join Date: Mar 2009
Posts: 1,471
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by cj56
this

cars running too rich
fuel pump constantly running
hard to start

check your oil and see if it smells like gas
thank you!
Old 09-23-2011, 06:47 PM
  #56  
TECH Junkie
Thread Starter
iTrader: (22)
 
camar0corey's Avatar
 
Join Date: May 2006
Location: Spring Hill, FL
Posts: 3,975
Likes: 0
Received 2 Likes on 2 Posts

Default

Latest update, pull plugs, rotate motor by hand, get fuel out. Insert dry spark plugs. Different PCM........

Same results! Cranked about two seconds then stopped, full of fuel already. What the hell has happened that this car is just dumping ungodly amounts of fuel at all the cylinders?!
Old 09-23-2011, 07:40 PM
  #57  
TECH Apprentice
iTrader: (1)
 
Purple Poncho's Avatar
 
Join Date: Apr 2004
Posts: 397
Received 6 Likes on 5 Posts

Default

Get a TTS log on it and look for "injector fault" on the right hand side of the program. If it is lit as a "1" you might have a harness problem. The injectors fire by grounding them. If you have the injector wiring grounded in the harness somewhere as soon as you turn your key on, your injector(s) will open full tilt.
Old 09-23-2011, 08:19 PM
  #58  
TECH Junkie
Thread Starter
iTrader: (22)
 
camar0corey's Avatar
 
Join Date: May 2006
Location: Spring Hill, FL
Posts: 3,975
Likes: 0
Received 2 Likes on 2 Posts

Default

Aren't all 8 injectors wired separately though or no?

I just don't understand how I drove the car to class Tuesday and back home. Then Wed. I load a tune, car starts but runs bad, didn't want to hold an idle. Shut down reload last tune that at least got me around. Cranks for about two seconds then the fuel hydrolock issue.

Can you clarify TTS log? Is that some feature in EFI Live?

All fuses check ok.
Old 09-23-2011, 09:08 PM
  #59  
That's MISTER MODERATOR
iTrader: (9)
 
Paul Bell's Avatar
 
Join Date: Nov 2005
Location: NYC
Posts: 7,591
Received 49 Likes on 40 Posts

Default

The fuel injectors should have one fuse per bank. They get full battery positive from the fuses. The battery negative (ground) is switched in the PCM. This gives the PCM the ability to monitor the injector's status.

As this is a wiring harness from EFI, the 4/7 "correction" should've been done in the wiring.

Your issues started when you changed the tune. You've also swapped the PCM.

>What tune is in this newly swapped in PCM?<

As the EFI harness & system makes the PCM "think" it's running a LS1, I suggest you swap in a stock LS1 PCM from a running car-without changing the tune, then see how things run.

For heavens sake, CHECK THAT OIL! All that fuel can and will wash down past the rings and fill the crankcase. You'll know when this has happened because your oil pressure will go way down as fuel can't be readily pumped by an oil pump.

Last edited by Paul Bell; 09-23-2011 at 09:15 PM.
Old 09-23-2011, 09:31 PM
  #60  
TECH Fanatic
iTrader: (11)
 
merim123's Avatar
 
Join Date: Oct 2005
Location: Chitown, IL
Posts: 1,892
Received 17 Likes on 15 Posts

Default

how sure are you that the tune loaded successfully? Any chance it didn't? worth loading a different file to check too. On EFI connection site, he has some sample files. That's what speedinc used as a base to get my tune done (so they told me anyway)


Quick Reply: 24x hell



All times are GMT -5. The time now is 06:16 PM.