super lean random condition

Well that throws pump and regulator out. Do you have another fuel controller to try? Pinch return line while idling it will slow fuel back to tank. It will keep pressure in fuel rail.
 
Rules out regulator? It ran much better when i pinched the return line. would'nt that mean its not closing and is bad?
I'm bypassing the GEMS and have it on the stock Harness at this point.
 
If you have adaquate fuel pressure at idle and you have good cylinder compression, then the next avenue to troubleshoot is either injector or sensor signals or voltages that might be incorrectly telling the ECU to run lean...
(air temp sensor, MAP sensor, BARO sensor, Coolant Temp sensor)
 
If ran better with return line pinched that's a possibility. there's a test for that. When i get home i'll look in service manual.
 
I'm thinking its a TPS sensor, get into the diagnostic mode on the gauge and see if the values look right. Make SURE the GEMS is NOT plugged in.

Your getting close put the match away...
 
Thanks everyone
Just did a compression check. Got 124 PSI on all four cylinders.
This is at 6200 ft, and a 40 thou head shim with a split gasket. sound right?
 
Not time for the torch just yet, I'm betting on the MAP sensor... When it doesn't read the correct vacuum signal then it doesn't result in the correct fueling, also an indicator is it stalls when you touch the throttle as it can't react to the change in vacuum (air flow).

The BARO sensor that is on the ECU bracket is the same sensor as the MAP, could try swapping them and see if it atleast idles and responds. The BARO reading is less crucial then the MAP when it comes to the engine running...
 
Intake air pressure voltage is to be between 4.75 to 5.25 volts with main switch on. Between positive pink/white and negative black/blue.
If that hose is pinched or clogged will cause it. Check all hoses. Maybe it's moving in the line and that's why sometimes it runs right and other times it doesn't.
 
Thanks guys.....
It's hard to guess what the problem is. I just don't have the cash to take it to the dealer for them to "guess" what's wrong.
I'll keep at it.
 
Cleared old codes from gauge,and re -started it. No codes show. look at code history in diagnostic mode and get two. 13 and 15. Air pressure sensor and TPS.
Clear codes again then switch the two pressure sensors as recomended and re-start. Again no codes at startup. Check code memory and see 15 again, but no 13.
It still ran crappy both ways,and i did swap back to stock wiring harness to check codes.
I have a TPS and pressure sensor on the way.
My understanding is code 15 TPS is normal with the GEMS. As well as TORS that I bypassed during the middle of this ordeal. So it was doing this with it active and obviously did not cure my problem.
 
Hey everybody
So i've pulled the throttle body's and went over every hose and connector and wiring i could see. Everything checks out. Installed new TPS and adjusted,also new manifold pressure sensor. Same as always.
Starts ok and runs at normal afr's for about 6-10 seconds,then afr's climb and max out my gauge. Increasingly running like crap.
I did notice a heavy residue in intake ports from race gas though. Could this be messing up my injectors? I'm also wondering if my pump is not supplying enough pressure after it primes the system?
This is so frusterating. Where is that torch. Also no codes anywhere.
At this point i am running it normaly aspirated on stock wiring harness.
Any more ideas??
Thanks
 
You must log in or register to reply here.

Similar threads

I
coolant under sparkplug boot
Replies
2
Views
811
SRXSRULE
SRXSRULE
stephenpen
Intermittent lean condition
2
Replies
17
Views
4K
MOUNTY
MOUNTY
BlgsRX-1mtn
Different Lean Condition
Replies
7
Views
1K
BlgsRX-1mtn
BlgsRX-1mtn
onrof
OIL spewed out the breather all over the motor!!!! WHY?
2 3 4
Replies
56
Views
12K
powershot1
P
insane
S/C fuel problem, stock regulator???
Replies
2
Views
977
machzed
machzed


Back
Top