HELP! She Runs....but......

[lkurek]

OK, as you guys may or may not have been following....I recently swapped a 1997 3.4DOHC/4T65E in place of my dead 1995 3100/4T60E. Long story, but I won't get into it again.....ask me though and I'll tell ya!

Anyhow, I finally got to the point of firing it up yesterday. Slathered on the JBWeld on the cracked front cover, and it appears to be holding....but I think I am still going to replace it eventually. Here's the deal:

It was very difficult to get fired up. Once I did, it ran like crap. I had to shim the throttle open slightly to keep it idling, and that was at around 1300rpm. Every time I gave it gas, it felt like it was gasping....and would only run up to about 3-4000rpm and cut out and backfire until the throttle was backed off. It warmed up fine, had good oil pressure, yada yada....however it DID have some rattling noise in the front (belt side) top of the engine. I think it might be a bad power steering pump. It was whining too.....

So here is my question..... I hooked up the scantool (Actron POS) to it, and it had good MAF readings, MAP readings, etc etc. The rear O2 was disabled in programming, but the front one was showing zero volts (when warmed and running). Cold, it was around .500v. In both cases, it was never moving around. Car was running very rich too.....my eyes were mildly burning, so I can see the .000v on the O2 being right. The loop status was alternating between closed and open about a second each. I also had a code that was lighting up (and flashing) the MIL.....P0300, misfire. I did hear a random miss in the open exhaust (has downpipe, but not hooked up to the rear section yet. My oil pressure light was flickering, so I have to look at that. I killed the motor, and it wouldn't restart. It cranked fine.... I tried the clear flood mode (floor the throttle before and during cranking) and all that got me was a nice backfire or two in the intake.

Any ideas? What should I look for? Any other data you need? It has good fuel pressure, all the wiring is good, fuses are good, etc.

What is this crankshaft position learn procedure for a replacement PCM? How do I do this without a Tech2?

Thanks as always guys!!!

[HayesPerformance]

What ECM are you running?

IF its the original ecm that came with that 97 dohc/4t65-E your fine.

If a crank shaft learn procedure is needed you'll get a P1336 Code (CKP System Variation Not Learned)

Put a new O2 sensor and pull all the plugs so all the gas can evaporate.

Do you have new plugs, wires, etc on it?

Let me know Larry

[lkurek]

Yes, I am running a 1997 PCM. I bought it used from a fellow list member, and he had it programmed by Mike at Milzy. However, he was going to use it on a 96 and run it with the 4T60 trans. Since I opted to go with the 4T65E, Mike repgrammed it back to stock, but killed the rear O2 check as I really didn't want to run that....

Yes, I have brand new wires and plugs on it.....as long as I had it out, that was easy enough to do (as would that front cover I have been talking to you about...had I known.)

The only code I have is a P0300, Misfire. Actually, it is in there twice, as I think it quickly reached the threshold for flashing the MIL. Could an "old" crank position test/value be in the PCM and be off so much that it affects how this one runs? I mean the engine and PCM were NOT originally paired up.....

I know fuel pressure is good, wiring is good, etc.... Injectors have sat in the engine for two years or so unused, so maybe they are seized up? The fuel pressure comes up and stays there without the engine running for hours....so at least the are not leaking. That doesn't help explain the running rich though....

Finally....and I doubt this is an issue......but I converted the O2 plug on the engine harness from teh 97+ square one, to the older style flat one. Connections are good and in the right positions..... Would the newer O2's not be electonically compatible with the 96- versions? They are both four wire.....

Sigh....this sucks. Everything is all all together, the re-wire went great, all the 3.4 DOHC speceific parts have been added.....and then this. A cracked front cover to start it off, and now running like a turd.

Anybody have any suggestions on a good scantool/editor with bi-directional support?

Thanks!

[lkurek]

OK.....dug a little today, as the car wouldn't start AT ALL....and was backfiring through the intake. I figured the cam timing was off somehow......and here is the weird part.....the cams themselves are still lined up perfectly, but the mark on the crank is may 60-75 degrees off! Yikes! I am going to pull the timing cover to see if the lower pulley on the cam drive is still timed correctly, and if it matches either the crank or the cams (I marked them all after I timed it). If it is still in line with the crank, the belt slipped somehow.....if it still lines up with the cams, then either the timing chain jumped or the lower pulley slipped on the shaft. Is that even possible? I never saw the back of one of those pulleys....is it keyed to the shaft? Or, does it attach like the cam pulleys do with a locking collar?

The fun continues......

[RedZMonte]

I would first think t-belt is off. Also dunno about running the old O2 with the new computer... If you unhook it, it should go into a "Limp" mode and run (a bit rich but run). I think the different O2's run different signals.... Could be wrong... but i would double check the timing.

S

[lkurek]

Wellll.....If you see my other post, I was wondering what was right.....my factory Helms manual, or the write up on this site about timing the cams. Of course, I decided to go with the Helms, as it is the FACTORY manual, right? Well.....no. It was WRONG and Ben was right. I should have known.....

In any case, I'm going to retime it this weekend and get it fired back up. Should run a LOT better when the other HALF of the cylinders are timed correctly and actually firing.

I'm frankly kind of suprised it even ran!

Well, I will post more after I retime......but I suspect that is going to be the issue, no?

Thanks....

Larry