I posted this in the gen 4 section yesterday before I realized we have a fueling section

2 weeks ago I was tuning the ve for the first time since the swap snce I run maf only so I never needed ve but felt what the heck Ill tune it. Anyways it happened twice that day. I would slowly climb the rpms higher and higher until the afr error was ok. The rpms would climb then buck and everything would shut down. I come to a stop turn the key off then back on and fire it right up and go along my way. Thought this was just because my afrs were so bad for that bit until I got them all back alined then went back to my normal tune and all was well. Coming back from a 45 min drive last week I was pulling away from a light and everything shut off again. Come to a stop start it back up and all was well. I brought it home looked over everything nothing looked out of place or burnt. Then today I was on a poker run and it happened again. This time I turned it off then back on while still rolling but it wouldnt start. Come to a stop starts right up press the gas and it dies again. Pop the hood look around smell around. Tap on the connectors on the ecu but nothing out of place. Get back in starts right up and moves again to problem. Then after a while on more level roads i feel it start sputtering and notice the wb is going crazy 12:1-16.8:1 while just cruising. Im able to back off on the throttle a bit since the road is leveling out and the afr goes back to normal for a bit then starts acting up. It never shut down but I never really had to get on it much at alll since the roads were more level. I think those other times where it shut down the afr was just going crazy plus accel caused it to stall out? But the thing is at each stop we would park for 20-30 mins then go to the next stop. When back to driving the afr would stay normal just bouncing around 14.3-15.1 for the first 15miles or so then start acting up again.

Any suggestions. The wb is in the drivers side right after the collector, Thinking lazy o2 but it only has 3000miles on it, maybe leaky injector??? Possibly spark plugs even though it runs fine for the first bit until it like gets hot or something? When the wb bounces around its not a slow change. I have a digital lc1 wb andwhatever the refresh rate is how fast it ws changing going from the 13s to 16s to 12s and a couple 11s in there while just cruising on open country roads so defintely no pe.

I put in a new aero 340 and racetronix hotwire kit over this past winter now it has about 1000 miles on it.

 

sounds like a voltage problem. just got done tuning a car that would just up and start acting up, the diodes in the alt. where going out, voltage would drop car would kick and sputter go crazy lean but never die and then like nothing ever happen run its *** off, would run fine for awhile then boom start acting up again

 

Hmm Ill check into that. Never noticed the lights dimming or anything but also never looked at my voltage gauge just wideband which correlated with the truck feelling like it was sputtering or surging while cruising.

 

Damn realized this isnt the fueling section, Any ways small update. Pulled the fuelrail and the checked the injectors, they were dry but it has been sitting for a day so that was expected. Ill have to jump the fuel pump and let it sit with some pressure for a little bit and see if they leak. Pulled the plugs and they all looked normal. Checked the grounds,(block to chassis, behind each head, original fuel pmp harness attached to the chassis by the drivers taillamp and the hotwire ground). All were tight, Still need to grab a fuel pressure tester and go for a ride and Ill also
datalog my voltage on that drive. Other then that its just more looking around which I did while I was under the engine and all the connections looked fine. Oh also switched the factory fuel pump relay with the horn one just incase.

 

Grabbed a fuel pressure tester. I varified the gauge by running a rubber tipped blow gun to it with the compresssor regulated to 60psi the fuel pressure gauge showed 60 so Im guessing its reading correctly.

Key on goes to ~ 65psi

running its sits at 75psi revving it backs down a bit then goes back to 75

As soon as I turn off the engine the gauge goes to zero. Bad check valve? I think it did that on the stock pump though too when I ran that last year. Always had to prime it before I cranked it or it would just crank a bit before it started, same as now with new pump.





Short drive not doing much





Im going to remove the return line and run a hose into a bucket to see if my return is blocked.

 

I'm not too sure what WB your using. I didn't see any mention of it in your post. But if your running the AEM UEGO, you should do some research on this

http://forum.aempower.com/forum/inde...c=25505.0;wap2

http://www.thirdgen.org/techboard/ca...tallation.html

I have this wide band and its a pain sometimes trying to tune your VE under cruising conditions. But it's more accurate during WOT pulls...weird enough.

 

if the return was blocked you would have sum stupid fuel pressure, I still think its electrical but good luck searching

 

Try to run it in SD and see how it acts

 

Im running a Innovate lc-1.

 

Not familiar with this type of WB. But, check all your grounds. Does this type of WB have to be calibrated at all? If so, I would check that as well.

 

Yep, I just did a free air cal a few weeks ago before I took the truck to the tuners, I dont think its a wideband issue though. I stays steady bouncing around 14.3-15.1 90% of the time but then its goes all over the place and in turn the truck stumbles so Im pretty sure its reading correctly.

I put vicegrips on the nylon braided russell pro classic hose that is my return. Turned the key and priming it went to 90psi then slowly went back to 0 over about a minute. What would this mean? With the return not "capped" it instantly goes back to 0.

 

It's most likely the LTFT's.

You're running in closed loop I presume?

 

Yes if thats runnin off the NB o2s, I always get the closed loop vs open loop confused haha.

 

closed loop is when the system is running its self, open loop is when you are adjusting the fuel. your check valve in the stock bucket is shot if the pressure is droping

 

Shot after 1000 miles?? Why would the pressure instantly drop with the return line open and slow way down when I crimp the return?

 

are you using a truck intake or car?
the truck intake has the check valve/reg. on the rail the car intake should be in the tank,
the pliers are make a check valve when you crimp the line shut

 

There are only three internal ways for fuel to go. Past pump, past return, past injectors. Proscess of illimination.

 

Also another check that relates to your issue is put the gauge drain hose into a bucket push the button and see if you can crack the thottle if it stumbles may have volume issue.

 

Running a ls3 intake, New 1000 mile old aeromotive 340, vette filter/regulator to convert to returnless.