LT1 dies.
02-28-2011, 08:21 AM
#1
On The Tree
Thread Starter
Join Date: Feb 2011
Posts: 132
Likes: 0
Received 0 Likes
on
0 Posts
LT1 dies. I've been running an LT1 (out of a 1993 Camaro) engine in my Jeep CJ7 for about 4 months with no issues, but now I have one that has my head spinning. This problem has so far only happened at night (with headlights on). I'll drive maybe 10 miles or so, good and warmed up, headlights blaring, fans going. I'll let off the gas to stop or slow down for a turn, and it just kills the engine. It's happened 3 times now in the last two nights, I'll sit on the side of the road for a couple minutes
, then after cranking for a bit (10 seconds or so), it'll fire back up and run until the next turn, or stop sign, then die again.
My battery cranks the engine over real, real strong, my alternator shows thats it's putting out 13.5V with all assecories on with a multimeter, but my gauge shows 11V. Is it possible that while driving highway speed, then coming to a stop, that my alternator can't keep up with all the needed amps for the headlights and fans, and it kills the engine when the RPM's decrease drastically?
Battery checked out excellent- 886 CCA with load test.
Thought of the opti, but wouldn't I have issues all the time if it was that?
I know the IAC is bad, but this couldn't be the problem could it?
Anyone have any thoughts?
, then after cranking for a bit (10 seconds or so), it'll fire back up and run until the next turn, or stop sign, then die again.My battery cranks the engine over real, real strong, my alternator shows thats it's putting out 13.5V with all assecories on with a multimeter, but my gauge shows 11V. Is it possible that while driving highway speed, then coming to a stop, that my alternator can't keep up with all the needed amps for the headlights and fans, and it kills the engine when the RPM's decrease drastically?
Battery checked out excellent- 886 CCA with load test.
Thought of the opti, but wouldn't I have issues all the time if it was that?
I know the IAC is bad, but this couldn't be the problem could it?
Anyone have any thoughts?
02-28-2011, 08:59 AM
#3
On The Tree
Thread Starter
Join Date: Feb 2011
Posts: 132
Likes: 0
Received 0 Likes
on
0 Posts
Sorry I forgot to mention a few things, my fuel pressure is constant at 45psi. Also when I wired it up, I didn't wire up a diagnostic plug, or SES light. So I can't read if it's throwing any codes. Sounds like I might need to do this in the near future. If I had a problem with my fuel pump, wouldn't it run like ***** all the time? I have an inline fuel pump right next to my fuel tank. And another thing is that this doesn't happen during the day, not so far anyway. I think the headlights being on has something to do with this, but....
Could bad coolant temp sensors be the problem? My gauge is reading a temp of between 160-200 degrees when hot, but if the other sensor if bad, will it confuse the ECM? I have only the pass side O2 sensor hooked up, but the thing runs really, really rich, and the idle is about 1500 when warm (bad IAC).
Another thing to add, is the last time it died on the road, it wouldn't restart for a few minutes, and as I was cranking during that time I could smell gas really strong.
I have a very strong maintenance background, but this has me scratching my head.
Could bad coolant temp sensors be the problem? My gauge is reading a temp of between 160-200 degrees when hot, but if the other sensor if bad, will it confuse the ECM? I have only the pass side O2 sensor hooked up, but the thing runs really, really rich, and the idle is about 1500 when warm (bad IAC).
Another thing to add, is the last time it died on the road, it wouldn't restart for a few minutes, and as I was cranking during that time I could smell gas really strong.
I have a very strong maintenance background, but this has me scratching my head.
02-28-2011, 09:11 AM
#4
Well, not to be an a$$ but if you know the IAC is bad, change it. What do u think keeps the air metered when you stop or slow down with throttle closed!!!!!!! I mean come on now. Its the obvious place to start, and it will cause stall outs and no starts.
02-28-2011, 09:22 AM
#5
On The Tree
Thread Starter
Join Date: Feb 2011
Posts: 132
Likes: 0
Received 0 Likes
on
0 Posts
It's been bad for the last 4 months, but this issue just started, but your right, I'll get that changed. Maybe I'm just thinking too much into this. The IAC is always open making it idle real high, thought it might be an issue if it was stuck closed, but if it's always open?? I'll get me a new one and go from there. Crossing my fingers on this, a new IAC at Oreillys is $108.
Trending Topics
02-28-2011, 03:01 PM
#9
Teching In
Join Date: Jun 2006
Posts: 16
Likes: 0
Received 0 Likes
on
0 Posts
this is probably going to sound stupid, but I've had almost the exact same issues with my car, and it seems to have turned out to be a bad pcv valve which was essentially creating a vacuum leak.
this may not be your problem, this may be un-related, however, it takes 2 seconds to check it, and $2.97 to replace it. might as well give it a shot.
this may not be your problem, this may be un-related, however, it takes 2 seconds to check it, and $2.97 to replace it. might as well give it a shot.
02-28-2011, 06:19 PM
#10
On The Tree
Thread Starter
Join Date: Feb 2011
Posts: 132
Likes: 0
Received 0 Likes
on
0 Posts
New IAC, just installed, PCV good, no vacuum leaks, Still idling at 1600 RPM's, flooding out and dying. My fuel pressure is about 45 psi, is it possible that my pressure regulator could be bad putting too much fuel in the engine, flooding it out and killing it?
02-28-2011, 06:22 PM
#11
On The Tree
Thread Starter
Join Date: Feb 2011
Posts: 132
Likes: 0
Received 0 Likes
on
0 Posts
So it was just sitting here idling at 1500 rpms, all the sudden the rpms shot up to 2500 and then dropped instantly and killed the engine with me just sitting there watching, I didn't touch nothin.. HELPPPPPPPP...
02-28-2011, 06:50 PM
#14
On The Tree
Thread Starter
Join Date: Feb 2011
Posts: 132
Likes: 0
Received 0 Likes
on
0 Posts
The guy who fabbed my exhaust didn't weld in a bung for one like i asked him too, so the plug is sitting there just hanging out on the driver side by the exhaust. Could I go to a junk yard and get the proper plug for a scan tool and how many wires from my harness would i have to hook up?
02-28-2011, 07:34 PM
#15
On The Tree
Thread Starter
Join Date: Feb 2011
Posts: 132
Likes: 0
Received 0 Likes
on
0 Posts
Man, these rpms are all over the place now, and this thing is really running like ***. I put that new IAC in it, and it's running worse then ever. The rpms will go from 3000 to 1000 all by itself, and eventually kill the engine with a big ploom of white smoke coming out the IAC port on the TB. What is the deal here? Now it seems my fans aren't working properly. WTF is happening?
:ban g:
:ban g:
02-28-2011, 08:14 PM
#16
Teching In
Join Date: Jun 2006
Posts: 16
Likes: 0
Received 0 Likes
on
0 Posts
this is a little gray for me because I've never swapped a motor into something that wouldn't have otherwise had that motor in it, but wouldn't the obdI connector be attached to either the wiring harness or the ecm/pcm...as part of it?
if it's not, you need to get one.
good news is that(if memory serves) it's still just obdI and any auto parts place should have a scanner they'll let you use for free, you just have to get there. bad news is that it may not tell you much, but anything is better than nothing at this point.
if it's not, you need to get one.
good news is that(if memory serves) it's still just obdI and any auto parts place should have a scanner they'll let you use for free, you just have to get there. bad news is that it may not tell you much, but anything is better than nothing at this point.
