hey i just got done dropping a 383 in my 1987 transam i go to start it up the first time it cranks right up but it won't idle it dies
if i dont give it some gas
if i do give it some gas it runs fine... even a little bit to just keept the rpms around 600/800?

engine specs
383
212/215 cam around 500ish lift
world s/r heads
ported intake manifold/superram
30lb accel injectors
hooker 2460 headers "open no exhaust"
custom 3inch cold air intake
58mm throttle body

i'm thinking maybe its the stock computer programing? i hope i got the right cam it does sound rather lopy doesnt sound like a 212/215 maybe thats the problem?

 

Check the voltage on your tps sensor first.

 

vacuum leak, or other air bypassing the MAF

 

ok there was a screw missing for the superram plenum so theres your vacoum leak and the tps sensor is new so theres your voltage being off i'll check out both..

i have one other question tho where does the pvc connect to? the plenums vacoum or that hole on the intake manifold?

 

Should connect to the TB; both of its hoses.

 

ok one last one what does the vacuum hose for the brake booster connect to?

i'm obveusly missing the little diagram for the vacuum system

 

There should be a 90 degree fitting in back of the superram on the driver's side of the back of the plenum.

 

HANG ON --- On a SuperRam the PCV valve connects to the intake manifold on the driver's side.

The breather/vent on the other side connects to the upper throttle body port on the passenger's side. The other throttle body port is for the charcoal canister.

Just did this conversion.


- Vern

 

Vern:

Looks and sounds like you did a S/D install, not a MAF install. Big difference in things like that.

Hooking anything vacuum up in such a way that it can draw in air that bypasses the MAF will cause idle problems. ALL air entering the intake MUST pass through the MAF, or must be compensated for in chip programming; otherwise it lets in umetered air, and the ECM won't know that it's there, to add fuel for it. Very different from S/D.

In a MAF system, there are 2 large connections on the TB. One is upstream of the throttles, one is downstream. Both obviously are downstream of the MAF. The one that hooks up behind the throttles is for the PCV valve; the one that hooks up in front of the throttles (on most TBs that's the larger one) is the fresh air supply to the other valve cover.

 

Yep! Mine was speed density, and I put the PCV to the intake manifold as specified in the directions. I can check later to see if they say to do it differently w/MAF oir just call Lingenfelter and ask them!).

Sorry if I confused the issue.....



- Vern

 

ok this is turning out to be a pain in the *** first theres a connector on the actually intake manifold the lower one next to one of the runners on the drivers side its rather large what does that go to?

 

THAT is where LPE/Accel says to connect the PCV valve that I mentioned in an earlier post.

 

That should work fine, since it's essentially the same place as the back half of the TB; as long as the clean air supply is hooked up to the place on the TB that it's supposed to be, such that the PCV valve is drawing in air that's been metered, and you have the OE PCV fitting on the TB plugged, you should be OK.

Where do you have the fitting on the other valve cover hooked to?

 

just a breather thats obveusly not going to work :/ juez i'm vacuum leak city i'm surprised the engine even runs

 

Vacuum leak city? How so? Did you find a bunch of leaks? Where?

 

now that i plugged all the vacuum leaks i found out i didnt install the "egr" temp senor in the egr vavle engine still isn't idling is that a direct hole in the egr that will cause a vauum leak?

 

Sorry, but what "EGR temp sensor" are you talking about? I've never seen one of those, just an EGR valve connected to an EGR solenioid is what I have on my 91 TPI 383 (both before and after the SuperRam install). Your setup may be differnt? But if you have an open port somewhere then that could be a vac leak.....

 

yeah there was a little round temp sensor or something that screwd into the EGR valve i didnt have connected once i get it all back together i'll post if it runs yet or not..

 

oh and i better add that i was getting a vacuum leak because one of the screws for the cover ontop of the plenum was missing when i bought it and i forgott all about it until i installed it.. the casting quality doesnt appear to good on these superrams.. plus its a real pain to put on/remove...

now that i'm sure i fixed everything we'll see how it goes.

 

so whats up?

running and idling ok?

 

I don't know if it will create a vacuum leak or not; but it may set a code. That's the ECM's diagnostic for whether the EGR system is functional.... if it recirculates exhaust gas, then when the ECM calls for it, it will get dosed with hot exhaust.

Did you get the PCV hooked up in such a way that all air that enters the intake has been through the MAF? i.e. no way for unmetered air to bypass the MAF and enter the mainfold?

 

yeah that was one of the problems.. i had a breather instead of a air intake from the manifold i fixed that.

this is my first engine swap and its taken over a year so bare with me

 

Did that help?

Is there any possibilty of anything else like that going on? Even a leak in the intake duct between the MAF and the TB can cause idle problems.

 

i havent tried starting it yet again i'm trying to fix everything first.. i'm still confused about some things could someone tell me where the coolent lines go from the throttle body? i know one of them goes to the lower intake manifold but where do the rest go?

btw i gutted that valve that used to connect to the throttle body that runs ontop of the passenger side valve cover.. i dont know if i really need it or not anymore its been so long since i've taken it off..

 

I done an LT1 swap in a 92 firebird,had to change to a higher volume fuelpump,hope this might help your problem.

 

That valve on the passenger's side valve cover that connects to the throttle body is strictly a vent to provide filtered air to the engine in response to the vacuum being pulled out by the PCV valve on the driver's side valve cover.

Have you ever tried sucking on a straw while your finger was over the other end? Remember how much easier it is to get anything thru the straw when you remove your finger? Well, that vent you "gutted" was the equivalent of the removed finger, it lets air in so the PCV valve can draw out the other side. It's connected to the throttle body so that only air that has gone thru your air filter (i.e., "clean" air) is drawn into your engine.

Hope this helps a little bit. Have a Great Day!!!


- Vern

 

got it running it the problem was a few vacuum leaks and i had a breather on one side of the engine so the pcv was pulling unregisterd air which i guess caused it to die out..

 

ok now it wont idle again every time i plug the mass air sensor in the car starts up fine then dies out like 1 sec later the rpms go up just after the engine started like its going to keep running then it just dies out... whats wrong with this piece of #@%#

if i leave the mass air sensor unplugged the car idles at around 1200rpm but idles

this car has sat for nearly two years and i've been walking to work i'm about to have it all towed to the crusher

 

OK, so what happened between 2 and 9 PM? Did you do anything under the hood at all?

 

plugged the mass air sensor in... its ok i think i know what has to be done.. i'm going to adjust the idle controll to open it up a little more since holding the gas down just a tad big keeps it idleing i'm figuring maybe the larger engine size just needs more air able to bypass the throttle blades.. so like i said if i hold the throttle open just a little bit the engine idles so i'll just adjust that little screw to hold the throttle blades open a little more.. i'm guessing the IAC valve cant let enough air into the engine..

does this sound about right?

 

well, that worked i also adjusted the TPS it idles at 1k in neutral and 700ish in drive so i guess thats fine for now.. but the engine is running pretty lean.. i'm off to bug the guys on DIY PROM board now