Got the break in miles on the 383(with le2 package) and got the 30lb injectors on it. Car is tuned by pcmforless. I got about twenty 75% to 90% blasts on the car tonight. It then dried up and I went out to do some WOT datalogging via datamaster around 5am since I was still up. Did a low 2nd gear punch while getting on the highway and everything went well. Then drove about 5 miles down the highway and got off on a side road. Did a 10mph punch, stall hit and pulled HARD through first. Shifted to 2nd and rpms started to drop off because of the shift and "pppsssshhhh"(almost like a blowoff valve) and the motor shutdown. It had no knock, no smoke out the back(that we could see at least since it was dark out), no fluids leaking. Popped the throttle body blades open and some light smoke (clear colored/white) came out. Everything else looked good. Then tried to start it and it just cranks. Went back to my house got some tools then pulled a plug and it looked fine. Tried starting it without the maf and no luck, replaced the map with another one we had and no luck, pulled the pcm fuse for 20 minutes, still no luck. Checked the oil via the dipstick tube and it still looks good, no metal shavings. It just cranks over but won't start.

I get a malf 33: "map high" sometimes when I first start the car and the idle drops to ~650. Been having this problem for the past week or so. I've only been getting this message since I put the 383 in, and the map worked fine on my old motor. Here's what the log shows(sorry I don't have a disk to get it on here right now, but can do later today if we can't get it going), injector cycle duty goes up to 89% max through 1st gear, so it looks normal. o2 mv stays from 900 to 955 at wot on both sides. I'm running in fuel trim cell 18 at wot. It Shifts from 1 to 2 at 6100. afgs goes from 15-17 at idle to high 200's then high 300's at wot. BUT right before the motor dies it goes from 347 to 74. Spark advance goes from 39 to 23 immediately(shows no spark retard either), but it still has high 80's injector cycle duty, then the motor shuts off. At no point during the wot run did it have any knock retard. Map showed 25-26 "hg at wot(baro was 28.5).

I'm not sure whats going on, but something is going wacko. I don't think the motor is hurt/trashed any, I think its a sensor that is going crazy. Could it be the pcm? If so I got another obdI swap, but its for a 6 speed, so can I just use tunercat to throw on my tune for the auto, or will that not work? Will it at least work enough that we can try to start the car?

Any other ideas? I'm going to go sleep on it for now, and I'll go back and look at it again early this afternoon to check everything out in the daylight.

 

Glad to hear that you got it running, how did it pull compared to the last setup? As far as troubleshooting it, just start with the basics, check for spark and then check for fuel.

Chris

EDIT: if you want, I can send a datalog of my dyno runs.

 

hmm....

i would assume it would at least start up after a reset of PCM if a sensor was bad?

if u get a bad MAP reading, then change the MAP sensor... maybe u have a vacuum leak related problem since MAP is throwing codes?

 

IF you got a scanner take the map sensor plug and wiggle it. Watch the voltage at a idle or even with the engine off for that matter. If you see it jumping with your wiggle than replace the harness end.

its a common problem.. IN fact a few weeks ago at the track just as I shifted into 3rd the car shut off.. With 10 psi aftercooled I thought for sure I broke something.. well pulled it over got the scanner out and saw that I had no map voltage so went under the hood and sure enough the map had come unplugged..

I like to think its because of all the G's... hahah

 

It pulled GOOD. Feels faster than my old motor, and by looking at the 89% cycle duty, it makes me think for sure that its making more power. I plan on starting with the basics, I'm about to head back out there and check it out.

Your datalog would be great, email it to me at a97blackformula@yahoo.com

As I said in my 1st post, we've already changed the map sensor. I thought it was the problem. I'll check for a vacuum leak, but I don't think I have one.

I'll give it a try when I get back to the car. Does datamaster show map voltage? I also have freescan and pcmcomm. I know it shows the map reading in "hg.

Alvin, can I use the 6 speed pcm(obdI swap just like mine) and load my auto tune on it or will it not work?

The weird part of it all is that the maf(afgs) reading went from 347 to 74(all at wot) right before it died. It then pulled timing and kept pumping in fuel, so I think it had to of went REALLY rich at that moment. I think thats why it died and made the blow off sound. I'm about to head out to check it all out, hopefully its a quick/easy fix.

 

Your timing chain man. Same exact thing happened to me. No mechanical noise when it shut off, no smoke no nothing. Car cranked over but no fire. Check that. -Brian Kaiser

 

I sure as fock hope not, thats a brand new focking extreme duty. If we can't get it going today, then I'll tow it home and pull it apart and check it I guess.

 

Well, pulled the valve cover and turned it over and NONE of the rockers moved, so the timing chain is broke. It's supposed to be the extreme heavy duty one, but the machine shop assembled the motor so I'm thinking maybe they put the stock one back in. Build sheet shows a HD one. Which if they did I'm going to be PISSED. My friend had them build the motor and then he had to part with it, so I picked it up from him, but I've dealt with the shop a few times.

Any ideas why it would break?

 

say hello to your bent valves, that sucks

 

Yeah, I bet it won't be pretty in there.

P.S. datalogs sent.

 

So, you think the OEM timing chain will not survive in a 383. I am building my 383 with cc306 and may use stock timing chain.

 

i used a standard cloyes double roller for factory roller cam in my lt4 383, just convert to a electric water pump

 

Don't use a stock chain. try to get a double roller or heavy duty unit.

Those who haven't upgraded to a electrice waterpump and standard double roller timing chain are living in the past...

Its a great way to go

*frees extra HP
*unloades driving a waterpump from the timing set
*cheaper timing sets.

 

exactly the same as me. dont waste your time w/a stock chain. just do it right the first time. hopefully you'll get lucky. after you get the new chain on, do a comp. check to make sure your valves arent bent. your gona have to loosen all teh rockers to turn the cam.
chris

 

Well, pulled it all apart and the chain is broke and almost all the teeth on the crank gear are stripped off. Good news is the machine shop said he'd honor it since it was probably a defect in the chain and is going to tear it all apart and check it out and then replace any bent valves since he assembled the motor. He's a good man for standing behind his work.

We ended up pulling the motor out the bottom tonight in 3 1/2 hours, including going to two different stores to get a fuel line disconnect tool since the 1st one didn't have it(lost my other one ), going to get a new socket(broke a craftsman on the k-member bolts), going to mcdonalds for some food, and without air tools. This is the 3rd one we've pulled out the bottom.

Now, few questions, if I run a double roller and ewp(which I want to run anyways), will it work with OBDII? I'm currently an obdI swap, but I might go back to OBDII someday. I might be able to get the entire double roller timing set for cheap enough that the machine shop will purchase it for me, which would rock. Anybody have part numbers for the chain/gears or the entire set? Also, is their anything special that needs to be done to run the double roller?