Check cliff notes at the end if your lazy :P

First off I noticed today that my fuel rail is leaking out of the rear passenger side fitting-very, very slowly. Its about one drop 20 seconds or so. Not much, but enough to cause a massive engine fire, or at least make me scared it'll cause one. I have the strange feeling its been doing this for a few weeks or so too :banghead:. I think this may be the excuse I've been needing to take the car off the road until i get brakes and suspension done, but I want to know how to fix this... ALL the o-rings have been replaced with GM and the o-rings on the injectors are new with the injectors, HOWEVER this fitting does NOT have an o-ring. I'm wondering if I should try soldering or brazing the joint, but it looks like its got like a composite cover or something.

My second problem is my tune. About two weeks ago the tune suddenly became very, very lean. BLM’s were at 155-160. I started dropping the injector constant to make up for it until I’m where I’m at now with a 22lb injector constant with 30lb SVO’s! At idle the BLM’s are around 135 or so right now, so I should probably go even a littler lower. The car should be running so rich that the cylinder walls are washed down, but the car is almost running fine. I double checked it with the wideband and it’s ok, around 14.7 during cruise, but WOT is a little more erratic than before it started this and is around 12 and below. Right now it runs ok, but just a little rougher idle, worse drive-ability, like the tune is way off, but… its kinda hard to explain

Car doesn’t run like a major vacuum leak, but checked for them anyway, sprayed carb cleaner around the intake ports to check for leaks, but no dice. Car isn’t using any more oil than usual and with the PCV disconnected it still pushes a small amount of smoke from the valve covers which is normal, so I don’t think the intake is leaking into the lifter valley. No exhaust leaks. No Codes, no sensors out of place or anything wrong that I could see. Reset the timing to be sure on it, 8 degrees base advance and around 24 degrees at idle with the ECM running the timing. I just changed the fuel filter two or three weeks ago. Fuel pressure is fine, 47 psi disconnected and 40 connected, meaning the car is pulling around 14” of vacuum If you use the 2/1 ratio, so once again, not looking like a vacuum leak with my cam (its not accurate, but should be close). I just traded tried my friends MAF out of his 88 formula 350 and it was reading almost exactly the same readings at idle (9gr/sec) and at 2000 rpm in park (17 gr/sec). Actually a bit of surprise as mine is completely gutted and his is stock and less than a .5 gr/sec difference. Looking back at old scans this seems right too. I set the valve lash at 1/16 turn a month or so ago. Not any valve noise either. The 30lb SVO’s have maybe 5000 miles on them and worked fine before, so I doubt its injectors. There is no CSI or EGR as I’m running a LT1 intake. I’m stumped!

CLIFF NOTES:

Car running close to right with a 22 inj constant w/ 30lb injectors. So its taking close to 50% more fuel than it should need. Car started this about two weeks ago all of a sudden. Still doesn’t run quite right.

<5000 on brand new injectors
no vacuum leaks
timing reset
Tried MAF off another car
No codes, no check engine light, etc
No bad sensor readings 3 wire o2 is switching a normal amount and seems to be ok
AFR where it should be according to the wideband
New fuel filter
Lash was reset a little over a month ago
No EGR or CSI to screw up.

The only things I can see that it could still be is:

A) Bad ECM maybe? still no codes, and what decreasing the inj. constant makes it better.
B) Maybe Ground or wiring problems with the ECM? Maybe something I did to install the Zeitronics Wideband screwed up a wire, but the car ran fine with it in there for a little over a week before this started happening. Once again no codes, no sensors off by the look of it on the scans.
C) Maybe its a Bad Fuel Pump? Seems like this would cause some weird fuel pressure problems but I haven’t noticed any at all. Is it a possible to do a fuel volume test? Like time the amount of fuel pumped from the Schrader valve in x amount of time? I probably need to replace it anyway, its just that it gets expensive to throw parts at problem real fast.


I’m stumped and although Grumpy says to give the car what it wants, something is certainly screwed up on my car!!!

In particular I’m curious as to what people have seen from their fuel pumps when they were on the way out?

Also anybody have some first hand experiences of weird grounds or wiring problems?

 

Ran the car with the STOCK memcal tonight. It was running 18-20 AFR, so even leaner than before, but there wasn't enough time for it to start raising the BLM's. Didn't take any scans, I just watched the wideband to make sure it wouldn't wash down the cylinder walls or something.

Went over a bunch of my old scans and from what i could see, at idle before this problem the Injector Pulses were 1.33 ms (the scan was in gear but off the gas, couldn't find a scan of the car at idle in park) and now its around 2.00-/+ ms at idle in park, so the ECM at least thinks its adding more fuel.

Also ran the car with the Wideband plugged in and it didn't change anything, doubt it would be its wired into my TPS, MAF, and a distributor wire.

I'm even more stumped now. I guess I'll borrow my friends ECM now and if that doesn't do it, I'll order a new fuel pump despite what my fuel pressure gauge is showing.

TPI gods I bow to you :hail: :hail: Please

 

Bueller? Bueller?





Got to thinking, first time I really started noticing this was after I installed an MSD coil... I think i'm going to throw the stocker back on and maybe replace the pickup on the distributor. Maybe borrow an ECM too to see if it helps.


Anyone have any weird problems after installing a MSD or other "high" voltage coil?

 

Might be mechanical. Did you check the water and hot-air crossover port alignment between the LT1 intake and the heads before you bolted them on?

Also check the rubber diaphram in your fuel pressure regulator, I have seen 2 go bad on the LT1 regulator as well as the tpi regulator.

Does the fuel pressure drop after you turn the car off?

 

The water ports cover great on the heads, I had material welded on to the tops of the coolant ports and the EGR ports before I ran the intake on stock heads. Now its on pro-lightning heads, so I don't think thats the problem.

The AFPR I have is a sealed design, Sealed like a stock one, but with the screw on top to raise the pressure, so there is no way to directly check the diaphram. Its not pushing fuel through the vacuum line, so I'd assume its ok. When I replace the fuel rail, hopefully the one i'm buying will have the stock FPR on it and I'll try replacing it anyway.

The fuel pressure does drop when I turn it off, like 5-10 psi a minute. I may try to check that tonight again...

I keep thinking its a fuel problem but the fuel pressure readings I have are so consistent. Then again they were consistent at WOT when my fuel filter was plugged and I had to add like 30% more fuel at WOT