Lucky#13

Help would be much appriciated.

I have -01 LS1 on my -68 camaro. Just recently completed my swap. There are still lot to do, but engine swap part of the project is basically done.

Everything worked great from first start to about 200 miles. Then out of nowhere she started to stumble and it gets worst all the time. Now she is not driveable at all.

She is running rough. Rich, way too rich. Stumbles and dies easily. Difficult to get idle. Feels and acts like when having manual choke on with a warm carburated engine.

Checked on HP Tuners and showed +40% too rich. From idle on. Scan shows like o-sensors could not "follow".

Engine is stock 2001 LS1. "New" ported Jantzen TB on. That is OEM TB which has been cleaned, ported and polished. MAF is original. O-sensors are new Bosch ones. Plug wires are MSD ones. Exhaust is headers, no cats.

Fuel pump is new Walbro 255 inline and vette regulator is used.


I have done the following:
- tried another maf (original)
- tried another o-sensors (AC delco)
- checked vacuum leaks
- tried another plug wires (original)
- checked TB and IAC

Nothing helps and every checked/replaced part looks okay. I even had battery cables off for 3 days and tried again. Same symptoms.

I am lost, donīt know what to do.

Any ideas?

Old Geezer

iTrader: (3)

Is the PCM the 1 that was originally w/ the engine?
Any codes set?
Since you have HPT, if you can get it running, why not do a data log, and post it??
Are the IAT and coolant temps reading correctly? [Check cold and hot]
What does the MAP sensor read, key on/engine off?
Have you verified all grounds?
Have you checked fuel psi?
Exh leaks?

O2's "could not follow"???
O2 volts engine off, key on?

Pocket

iTrader: (22)

Check the IAT during a run scan. I remember the STFTs going mid 40's with the IAT unhooked

Next, check for a leaky injector(s)

If those are ok, have you done a crank relearn since installing the engine. It wont always throw the relearn code when it needs one and can seriously muck up how the car runs. You can do a search on my name for a detailed list of symptoms "Drivability issues"

nastychevelle

iTrader: (7)

just tell people it has a cam

Lucky#13

Thanks for all tips.

PCM is engine original and running ok. Fuel trim readings are odd. High peaks every now and then.

Just got a Snap On fuel pressure gauge from a shop, I will have to return it tomorrow morning. Reading at rail shows around 10 psi?! Isnīt that very low. I thought it should be around 50 psi. Am I right?

Maybe my vette filter/regu is blocked up or something. It was brand new WIX unit. I will have new AC Delco unit by tomorrow or so.

I was thinking to replace the filter/regulator and I have another set of OEM injectors which I will try on after replacing the FPR.

Will the vette regu/filter handle the pressure that Walbro 255 pump can produce?

Any ideas? What the reading at rail should be?

Lucky#13

Here is how it looks on HPTuners

Pop N Wood

iTrader: (1)

Yes, pressure is way low. Not uncommon for a new swap to spew junk out of the tank clogging a filter.

But at the same time you are running rich. Stuck injector?

Lucky#13

That is what I am thinking also. I have another set which I will try on after I have replaced the vette filter/regulator.

1quickirocz

well if the FTs are reading +40 then the PCM is adding fuel because it thinks its lean not rich. Is it actually rich ( smoking) or just running like crap from poss a lean condition? If the fuel press is at 10 PSI that would most deff explain why your FTs are at +40. If it were rich the PCM would be pulling fuel (-40) if the O2s are reading correctly.

Lucky#13

I have tried 2 set of O2s with no difference. So I am thinking that they are reading ok. On the other hand O2 readings do look funny on screen. I know they should "move" back and forth when running but they just look "lazy". Before start, when power is on, they do look okay.

It is not really smoking, just smelling heavily and running like crap.

1quickirocz

Do they stay below 500 mv most of the time when its running bad? Is that 10 PSI while its running or key on(prime)?

Pocket

iTrader: (22)

Unplug the O2s to throw them out of the equation. When the engine is running that far off, they will act a little strange

Lucky#13

Tried that with no difference

Lucky#13

I will check the mvīs. I donīt have HP T but my frieds does. That is why I am totally out from laptop tuning. But I am learning everyday

10 psi is both on prime and when running. (If one can call it running)

Lucky#13

Yes it does stay below 500 mv all the time while running bad. And it is just running bad.

Lucky#13

Replaced the vette FPR/filter. After that worked like a clock

Feels stronger than ever.

Thanks to everybody.

1quickirocz

Cool glad you got it straight. I had one in the shop the other day with a filter/reg that had almost 90 PSI at the fuel rail. that was a 4 cyl s10 haha. bad regulator was the cause for that as well. now you can enjoy it again. good luck.

Lucky#13

Thanks!