How much boost at idle???

[91integraturbo]

Hey

How much boost should I have at idle? I've been having a odd problem. I recently installed a t3/t4 turbo and at first I had boost. I didnt have a gauge installed yet but air was blowing from nearly all intake vacuum lines. Then the next day I put a boost gauge in and it read 0 boost and I have no air out the intake vacuum lines. If you put the motor under load though you can plainly hear the turbo spool up. Before though you couldn't hear it spooling but a lot of air was coming out of the intake. I didn't try putting it under load when I felt air coming from the intake originally. The gauge I purchased also came with oil type plumbing so I put it on the turbo where the waste gate is with a T fitting. If you're just idleing and you hold the intercooler rubber piping you can feel that it isnt boosting but if you then press the gas to 6000 rpm you still don't feel it expand (you also don't hear it spool, but under load you do hear it spool). A matter a fact while idleing (I didn't try it while reving) you can stop the blade on the intake side of the turbo easily with your finger. It's like the exhaust isn't strong enough to spin the turbine or maybe all the exhaust isnt being forced through the turbine. I've ordered another turbo and didnt want to put it in until I could figure out what went wrong with the first one. Anyone have any ideas let me know I can also answer any other questions that may help you understand what might have happened. the only thing I can think of is possibly, I did have the pcv hose blocked off for the initial start up(I didnt realize it was plugged up had a collapsed hose) and maybe the postive pressure in the crank case prevented the turbo from draining oil correctly. It was also smoking pretty bad and when I took the turbo back off and took the downpipe down there was a lot of thick sticky oil around the turbine. while I had the turbo off I cleaned all that up and now it don't smoke at all but still no boost. Neither sides of the turbo leak oil or anything. It still spins super easily as well. You can spin it with your finger and it keeps spinning for another 2 seconds or more. please any ideas would be super helpful.

[g2nickle]

You should be in a vacuum at idle and under partial throttle(no boost)should only be in boost when your getting on it.

[91integraturbo]

Hey

Thanks for letting me know about the amount of boost at idle. One more question though was it some sort of fluke that I had a lot of boost coming from the intake vacuum lines at idle originally? At idle you could hold your hand about 6 inches from the port that the pcv originally went to and you could feel boost. Not only that port but any port I unplugged to feel for boost I could feel it. I recently put it half way up the ramps and pulled the e-brake on the ramps so I could put it under load. At idle it has about 18 to 19 vacuum on gauge and once I put it under load it goes to 0 which makes sense since you are opening the throttle which equalizes pressure but gauge never registers boost no matter how much load I put it under. Stays at 0 boost but you can hear the turbo spooling up really loud. Should I try getting it on the road and gunning it WOT to see if it registers boost on the gauge? Any ideas? thanks

[CRX 2 NV]

the turbo needs load

it needs resistance, free revving the motor will not put enough load on it to produce much of any boost, you need to be in gear with resistance from the road.

i would take it out to an open road and do 3rd or 4th gear pull at wot starting at 3000rpm watching the gauge closely

if you still aren't getting boost under load you have a boost leak

[mike@synapse]

at idle you will never have boost. you were likely feeling vacuum from the motor. when the throttle plate is closed. the engine displaces more air than can get by the throttle plate in that given amount of time, therefore you have a vacuum(x amount of volume and only .2x air to fill it).

at idle there isnt much exhaust gases spinning the turbo. sometimes not even enough to move certain turbos, and definately not enough to make boost. even just free revving the motor will not generate boost. you must be driving to car to generate boost.

[91integraturbo]

Ok now I'm getting boost but it keeps throwing trouble code 3 for the map sensor. At about 4000 rpms check engine light comes on and it will no longer idle. I do have the missing link in as well. It will never rev past 4500 rpms for some reason. Will the msd 6462 fix the map sensor problem and the retarding with more boost problem or will I need to get a different msd component? Will the msd 6462 let me add a different map sensor?

[g2nickle]

You need to list a detailed parts list of your setup and stop starting/running/driving the car before you BLOW it up. List what kind of fuel management your using, injectors, fmu, fuel pump, ecu, tuning program, everything and dont start the car again.

[91integraturbo]

Do you know of any good sites/links that sell the ecu and tuning programs? Since the car is a 1991 it don't have OBD 1 ecu (i think) and the map sensor is mounted on the firewall with vacuum coming from the intake. I have 2.0 injectors in along with a 255 fuel pump. A fuel regulator that came with the turbo kit along with a oil cooler. The motor is quite new I recently rebuilt it. The cams and springs are stock wanted to upgrade later. Most of the stuff is stock so I already know that is why it isn't running very well. I was going to try using a 94-01 throttle body since the map sensor is on the throttle body and just plugging it in to my ecu (map sensor) but I dont think my ecu will understand the voltage coming from the 94-01 map sensor. I have seen these sites and ebay where you send in your ecu and they install the tuning program like hondata but I believe my ecu isn't a OBD 1 so I don't think they'll do it. Any suggestions on what I should do or purchase as in ECU and fuel management components?

[accord_limited1]

You are walking down the path to nuke ur motor ;( the fuel pump and the fpr are a good start but you need to know what your fp is as well as ur a/f ratio in order to correctly tune the motor. Depending on the boost u want to run ur probly going to need bigger injectors. A good way to tune is a apexi safc with a set of dsm 450cc injectors along with ur fpr. I use to own a shop and installed many low budget turbo set ups. I also fixxed many low budget turbo set ups that people didnt tune correctly :I( turbos can be fun or really really sad. If you would like some more comprehensive help toss me a instant message i can try and help point you in the right direction.

I hope this helps

Nathan

[98vtec]

convert to OBD1 and get it tuned. Period.

and there is a way to build boost at 0mph, but you have to have an engine management with the anti-lag capabilities.

Look into getting tuned on eCtune or NepTune, or crome if no one can do neptune or ectune.

[trev0006]

should be zero.