sr20det bogging and lag problems

[brianbish93]

Hi i've had nothing but problems with my sr20det, just finished compression test 160 each cylinder, mods are front mount ic, greddy intake, hks wastegate, headers, 3in catback exhaust and thats pretty much it.
Car is backfiring so im guessing that it is running rich, but under accelleration it boggs out and doesnt want to move , if it does go, it shows that I do have normal boost but the car goes nowhere, it feels liek the turbo isnt doing anything, at idle vacuum is around -18. any ideas on where to start ? I have to drive the car 600 miles in 4 days to get home from school so if anyone could help i would really appreciate it! I did do research but still cant find the answer i need

[Drift95silvia]

Get a fuel pressure gauge and see if your keeping your fuel pressure under acceleration. I was having similar issues and it turned out to be my fuel pump relay was going bad and would cut out after the car was up to temp. I would check that also I would check your TPS and MAF to make sure they right.

[brianbish93]

that makes sense, because it only does it when the cars warmed up

[brianbish93]

how to i fix that if the relay is the problem

[drift213]

If the relay is the problem change the damn relay.... Make sure your maf its clean or you dont have vaccum leaks

[brianbish93]

i meant test it but im just going to go buy a new one, and if i had a vacuum leak could i still be running the right vacuum at idle?

[Drift95silvia]

On mine I tried two new relay's and both went bad in no time flat so I I did is got a 30amp fused wire loop and just bypassed the relay. been running daily for over 4 months now. no issues "knocks on wood" and I have taken a couple of hour long or better drive's to really test it.

[AsleepAltima]

is everything still stock sr20? no different maf or injectors?

[brianbish93]

i think its a z32 maf and stock injectors

[brianbish93]

On mine I tried two new relay's and both went bad in no time flat so I I did is got a 30amp fused wire loop and just bypassed the relay. been running daily for over 4 months now. no issues "knocks on wood" and I have taken a couple of hour long or better drive's to really test it.

is it safe to do that?

[AsleepAltima]

was the ecu tuned for that maf?

[brianbish93]

was the ecu tuned for that maf?

i dont believe so, but it could still be the stock one, the car ran perfect until i went on a long drive and then the wastegate went and i had terrible boost spikes, i replace the wastegate and now its boosting normal, just doesnt feel like 8 lbs of boost , and once the cars warmed up it bogs under accelleration so im not sure if it would be the tune

[Drift95silvia]

That is how you direct wire a fuel pump on a race car just install a fuse in the path of the wire any thing goes bad fuse blows car shuts down.. wire goes dead.

[brianbish93]

That is how you direct wire a fuel pump on a race car just install a fuse in the path of the wire any thing goes bad fuse blows car shuts down.. wire goes dead.

i just turned my key to the on position and the usually whine that i hear of the fuel pump sounded really weak, could that mean bad fuel pump or still bad relay?

[AsleepAltima]

take a pic of the maf and post it if you can, of the data plate. id check temp related things too - like the coolant temp switch. i dont think it can make it run that drastically bad, but something is making it bog. gotta check the simple stuff first. boost leaks too - check all of your hoses/tubes and clamps.

[silviaks2nr]

It just sounds like a boost leak. Pressure test the system. Changing the mafs placement (even when just reinstalling it onto the inlet pipe) can cause problems too. what is your mafs voltage at idle?

also, there is ZERO advantage to running a larger MAFS before upgrading your injectors. Stock injectors max HP is much lower than stock MAFS.

[brianbish93]

since i am away at school i dont have any tools with my , i do have basic tools, a voltage meter and a vacuum pump, is there any easy way to check the ic piping for leaks? and i will go check the voltage nowhttp://s258.photobucket.com/albums/hh253/brianbish93/?action=view&current=IMG-20120624-00080.jpg

[brianbish93]

http://i258.photobucket.com/albums/hh253/brianbish93/IMG-20120624-00080.jpg

[wyang]

Check your spark plugs. Make sure its gap correctly.

[benarovi]

check the timing. also boost leak test.

[AsleepAltima]

i would definitely check for boost leaks. i doubt seriously the plug gaps are going to cause a problem right now UNLESS when the wg went kaput, he knocked badly and closed the gaps. it would be a safe bet to at least pull the plugs and make sure they arent closed from knock. if the maf registers bad, i think i have another stock sr maf and im very close to you so the mail would get to you quick.

[cbcm2435]

i meant test it but im just going to go buy a new one, and if i had a vacuum leak could i still be running the right vacuum at idle?

testing a relay is actually really easy, there are four prongs on the bottom two are for the magnetic coil, and two are for the switch, when unpluged you should get some resistance between the two for the coil, and to test the resistance for the switch, all you have to do is energize the coil side so the switch closes and test the resistance across the switch (which should be about 0 ohms)

[brianbish93]

Thanks for the input everyone,I'm waiting on tools from a friend , I will get back to you tomorrow when I check the plugs and reading on maf

[cbcm2435]

FYI next time post stuff like this in the tech section

[zneubauer]

Yeah I'd check plug gap and maf.

[driftballerdet]

i had this problem with my sr i tried to alleviate this problem many different ways..... in short turned out it was a boost leak replace your couplers

[brianbish93]

Thanks for all the help everyone, just found a hole in my intercooler, after I fix that I will test and get back to this and try fuel and plugs if it doesn't help

[brianbish93]

for future people that look at this with the same issue, it turned out to be a bad fuel pump