First real launch....problem!!!!

Injected1

Injected1

Member
Well I finally got the engine in, transfer case and governor swapped out and still couldn't step on the gas because the IC kept blowing off. Fabbed up some brackets today and got to do my first real boost launch. The truck is all stock except for a 20g and 3000 stall converter. Saving my money for 50#'s and AFPR to go with my STG Ultimate. The launch went well smoking all four about 10ft then screamed through first into second. At the top of second 4500rpm/ 50 mph or so the tach dropped all the way dpown to 2000 and it felt like I hit the brakes. What should I look for? Fuel? Spark?

Thanks, Nick
 
SY2455

SY2455

70's Veteran
Re: First real launch....problem!!!!

How much gas do you have in the gas tank? On my truck you can't do that below 3/8 of a tank, because all the gas will go to the rear of the tank and cause the engine to go lean. Also recheck your intercooler to throttle body hose or the turbo to intercooler hose.
 
qbnkiller

qbnkiller

Conflaguration Specialist
Re: First real launch....problem!!!!

Did you peg the boost gauge? You might have hit fuel cut (overboost)....been there - done that (when I was stock)!
 
Injected1

Injected1

Member
Re: First real launch....problem!!!!

All the intercooler, turbo parts were bracketed (finally) and the hard pipe is in there so tight we had to lube up the couples so they wold slide on. However the gas part is very possible. I'll check, could it be fuel pump? I think I have a Walbro but haven't had the fuel tank out yet, but it's loud. I do have a KenneBell Boost-a-pump that I could install or I have an extra 255 - I could pull the fuel tank and install. Could it be that I need an AFPR? Any suggestions? Thanks
 
Injected1

Injected1

Member
Re: First real launch....problem!!!!

Ok guys I drove to truck some more today and ruled out the fuel sloshing theory because I now have a full tank. My brother had a Zeitrex wideband 02 that he let me borrow and I am about to hook that up and an aftermarket boost gauge. Here is a clarification on exactly what is happening. At Wot in 2nd gear the tach (factory) screams up to 4200 and then hangs there for a second, foot to the floor and the tach jumps to 6500 and bounces around alot till it falls to 2000 and the boost gauge does the same thing, to the top then to the bottom and it feels like I pushed the brakes. The motor doesn't rev to 6500 thank god just the tach, it's like a complete electronic stall. After that the trucks power comes back on and drives normal. Then the check engine light comes on for about 5 seconds then goes off and doesn't come back on until I do another boost launch til it happens again.

What should I look for? Please help.
 
bezerk

bezerk

New member
Re: First real launch....problem!!!!

look for datamaster of tunerpro to make a log on your truck..or skip this and
look for a new engine
 
Injected1

Injected1

Member
Re: First real launch....problem!!!!

Bezerk don't say that it is a brand new engine and I am out of money for now. How do I cure the overboost? How much is it going to cost me and what exactly am I going to need besides a laptop for the datamaster? I am going to run it to the shop on monday and try to pull the codes although last time the port wasn't getting power. Does it run off the same fuse as the cigarette lighter?
 
bezerk

bezerk

New member
Re: First real launch....problem!!!!

it just takes a laptop and a usb cable from RPM, datamaster you can download and use for 10 runs.
you really need to do that!!!!once again i will say you need a new engine if you don't know your tune.
it can be overboost you set the wastegate rod a few more turns longer or check your vacuum lines. but datamaster kinda tells you wassup and what you've done
 
Injected1

Injected1

Member
Re: First real launch....problem!!!!

Cool I will do that. How exactly do you turn the boost down on the wastegate? Srock style with rod.
 
qbnkiller

qbnkiller

Conflaguration Specialist
Re: First real launch....problem!!!!

You can take the truck to Autozone and have them read the code for free. Once again, from the description you are giving, it sounds like you are overboosting. What has been done to the truck ( be explicit - even the littlest things could help narrow it down.
 
qbnkiller

qbnkiller

Conflaguration Specialist
Re: First real launch....problem!!!!

Before you adjust anything, verify all your connections/vacuum lines!
 
Injected1

Injected1

Member
Re: First real launch....problem!!!!

I bought the truck in December with a stuck valve and a bed full of extra parts for $5000. I ran a comp check and pulled 55 on #5. I pulled the heads and the motor was full of nasty sludge. I had an original 93 ty motor that pulled 165 on all 1-6 and did a longblock swap. I deleted the egr and canister. Installed a 20g and a 3000 stall converter. The tranny governor was spent and was what caused the bent valve by over reving so I swapped it with the one out of the Ty. I plan on doing 50# injectors and Afpr to go with the unused Stg chip for 50#'s that came with the truck when I bought it. Taylor wires and cr42ts gapped to .032. Hope that helps. Oh yeah and not to sure about the fuel pump. could be a Walbro or the stock one going out (it's loud)
 
Quickstop [UK]

Quickstop [UK]

Combating adversyty.
Re: First real launch....problem!!!!

So what codes are you getting?

Just jumper the ALDL terminals with the ignition on but the engine off and you'll know your codes - no need to go toa place.

Datamaster will really help you on this one but you have tach flutter - do a search.

Have you verified all your engine grounds? Seeing as you did a swap this could help. And it's cheap.
 
Injected1

Injected1

Member
Re: First real launch....problem!!!!

Ok so I pulled the codes today on my friends DETERMINATOR and I got codes 31, 33, 43. I then took the truck for for a drive with the datastream going and a/f was 14.7 cruising and when I got on the gas the lowest it dropped under boost was was 11.7 so I am pretty happy with that. However the boost psi went to 17 before the overboost cut it out again. Didn't mean to do that. What psi should I have the wastegate set to on a stock block that the heads have never been off of. Is 15psi the magic number or is 14 better.
 
Injected1

Injected1

Member
Re: First real launch....problem!!!!

Ok so I switched MAP sensors and adjusted the wastegate. Didn't go far enough......damn. I guess I'll take it all back apart tommorow and do two more full turns. I apeciate all the help everyone. Hey does anyone have a 20g wastegate? I think I have the Wg for the stock turbo on there. Anybody have any pics of either of the actuators so that I can be sure.
 
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