420a-t Head re-done, now having issues?

[radeagle]

I posted on here back in August that my Underdrive pulley fell off and then my car wouldnt start. Well I found out that the timing jumped in the process bending all Intake valves when they hit the pistons.
I got the head redone and put it all back together, and now its running rich then lean then perfect then lean....and back again. It dies after i get into the throttle and let off, but runs perfectly fine(13 on my wideband) at 65mph. once i slow to 30 it starts running rich(11-12) and then when I stop it goes lean(15). At idle it is very lopy and ruff. Also when its under boost it drops just under 11. Ive checked every vacuum, made sure everything is plugged in. I changed my Upstream O2 sensor, nothing seems to work. The car ran absolutely great before the head issue, but I dont know what is different now.

Ive read a lot of threads about boosted 420a cars running lean, but it seems that they are just putting a turbo on a stock engine running 4-8psi. This engine is well built and has ran up to 28psi on a dyno. Currently I have the two stage boost controller at 14psi and 20psi. What Im trying to say is I cant find this issue anywhere so any help would be appreciated.

 

[jayson427]

If your car sounds lopey and ruff you need to double check your timing. When you put the head back on did you line the crank sprocket up then the cam gears? When you put the belt on did you make sure the tensioner didn't move?

 

[radeagle]

My bro did the timing and I think he might have done it the opposite...cam and then crank. Je said I might have smashed my lifters on the intake side when I jumped timing.
Also I can't find a maf sensor anywhere to see if that is it...is there such a thing as a maf delete?

 

[jayson427]

There is no maf on a 420a. Did you rebuild the head? What all was replaced? It's a pain in the ass but you have to check timing.

 

[silvreclips]

If this were mine I would first pull the codes on the CEL to see if the ECU has caught anything obvious. Im assuming you have EGR deleted so you probably have a CEL all the time so you dont know if a problem comes up or not. I would also check the fuel pressure. I see you have a AFPR. Also a vac leak could be the issue as well. Usually you will have a high idle as well but not on a small leak.

Also you have a lot of work done on that car but you are now just finding out the 420a doesnt run a MAF sensor? Sounds like you have had shops do most of the work on the car, maybe they should be checking this out if you dont catch anything obvious.

 

[radeagle]

I bought the car built and 5 days later the timing thing happend I Googled it and found out there is no maf not long after my comment.
The timing is spot on. I just took it for another test run. I went about 5 miles each way and I filled up with 93 after the first 5. On the way out there it was running right at 13 until the end and it went up to 14 and it was idling good. After I filled up I drove back and it bounced from 14.5 to 15 even with the throttle being steady....and now it won't idle smooth.

 

[dsmcrzy]

I am thinking it might be something more in your tune than anything. Especially since you say the timing is dead on. What are you using to tune the engine with?

 

[radeagle]

I don't know what it was tuned with before, but the previous owner is sending me the disc they used. It was tuned at a shop in South Bend, IN. Anyone around the Lafayette, IN area who knows how to tune these cars??

 

[silvreclips]

The car should be running off the stock ECU so a portfueler tune should not be effecting you off boost performance. Check the cel out and see if you get anything

 

[Tyeler18]

In the mods it says you have portfueler which I know nothing about wish I could help. You definitely need to dial in your tune even cruising at 14 is to lean. Stay out of boost and watch your Wideband. Get it into a shop, I'm surprised the guy didn't give you the laptop he was using to tune the car so you had something to look at.

14 is lean? 14.7 is stoich which is what they should idle and cruise at under "perfect emissions" I run as lean as 18:1 during cruise to maximize MPG. 14.7 is actually relatively rich if you're going by economy standards

This is the problem with buyer a "built" car you know nothing about. You need to find out what kind of program is being use to tune and do a compression test. It's possible your "tune" was erased when you disconnected the battery (i'd assume you disconnected the battery when you did the head).

 

[radeagle]

I finally was able to get enough time to jack the car up and pull everything off and get my eye right up to the crank and line up the timing marks and when I climbed out from under the car the rear cam was advanced one tooth. It is now in time and runs like a raped ape! Thanks for all the imput/advice. I've learned a lot from this....but I'm sure I'll be back on here soon enough with another issue.

I will add that I called Area One Motorsports (the place that dyno tuned the car) and they said there is no way I deleted the tune by disconnecting the battery.