misses and runs rich

[90laserIA]

ok so here is my problem at idle the car runs crazy rich and misses alot and when you try to rev it is misses until 3k rpm when it sounds like it hits fuel cut It ran fine last saturday until i pulled the top intake pipe off to get to a coolant hose that was broken fixed it and put the intake pipe back on and tightened the clamps and fired it up and this problem started i've replaced all the vaccume lines the maf and the o2 sensor and it still runs like this i also noted my sunpro boost gauge reads 10 vac and the stock gauge reads 7 boost at idle and when you rev it the sunpro hits 5 boost when the stock gauge reads 14 boost what i've double checked all vac lines and intake piping and can't find anything there also did a Idle speed stabilizer and a TPS new coil,wires,and plugs i noticed it runs slightly better with the maf unhooked < just bought a new one and still does it

### help would really like to get the car running soon i'd like to get it so i can get it to the shop and give it a new paint job and finish the interior

should also state that it does need a tune but it ran fine before just hit fuel cut because of the 16g evo turbo i'm running but as stated it ran fine before, max boost i have ran is 16 psi

 

[reallyslowfwd]

have you done a boost leak test?

 

[90laserIA]

not yet will do that today also read something about having 2 02 sensors is that true on these 1g dsm's

 

[xxNocturnalxx]

Generally pre 96' is OBD1, that generally means 1 o2 sensor, especially for a 90' DSM.

 

[90laserIA]

Generally pre 96' is OBD1, that generally means 1 o2 sensor, especially for a 90' DSM.

thats what i thought i haven't had a chance to get it up in the air and look under it but may be doing that tomorrow anyway

 

[90laserIA]

thats what i thought i haven't had a chance to get it up in the air and look under it but may be doing that tomorrow anyway

did a BLT and found 2 one was at J pipe other was bad pcv valve car runs better but does still have the same poblem except does idle and rev a little better

 

[clipto]

So your running 16g on stock fuel system and stock ecu? Also what spark plugs and spark plug gap. Grab atleast a walbro 255. Do you have a wideband? How much boost is it going to? Do you have boost gauge? You need those things.

 

[90laserIA]

So your running 16g on stock fuel system and stock ecu? Also what spark plugs and spark plug gap. Grab atleast a walbro 255. Do you have a wideband? How much boost is it going to? Do you have boost gauge? You need those things.

to answer your questions yes stock fuel system, no to wideband untill i get dsm link, ngk plugs will check numbers later gap is .028, boost is 16 psi or it was can't drive it to say if it still is

if i unhook the maf it will rev better and actually drive, it just wont cruise

 

[92AWDHX40]

I would get logger to help or a tuning device cant do much without being able to see whats going on any cels.

 

[WES_393]

it does need a tune but it ran fine before just hit fuel cut because of the 16g evo turbo i'm running but as stated it ran fine before, max boost i have ran is 16 psi

If your hitting fuel cut, the car is not running fine. Fuel cut is the car saying that your risking serious damage to the engine. If it's not already too late, turn the boost down. You should be running about 10psi until you have a wideband and some fuel mods. The stock fuel system can't safely handle much more than that.

First thing you need to do is run a boost leak test. Fix any leaks you find and update with your progress.

 

[NC_Dirt_Racer]

Turn the boost down to around 10-12. Upgrade injectors and get a walbro 255 pump and throw a wide band Air fuel gauge on it then you can turn the boost back up.

 

[90laserIA]

ok so here is the deal after i unhooked the MAF it runs way better its not running rich an i can drive it and it cruised the short 5 mile drive i went on its now only running 12 psi boost couldn't get it any lower <i did find a hole in fpr vac line, local Mechanic told me to check injector size is it possible that with the stock ecu tune and stock maf that it would run like this with larger injectors on a stock ecu ? if not anybody know how to test the maf for voltage fluctuations at the plug and at the ecu so i can cross that off my list also please don't say check for boost leaks i did that and it held 28 psi for 40 seconds

will still not run if maf is hooked up and its a reman stock unit from a1 that i got monday

 

[90laserIA]

i checked the ecu wiring with a pin-out chart and pin 6 and pin 14 were in the wrong place like the PO had used a 91+ ecu or wiring harness at some point but didn't change them back when putting the 90 ecu in.

I also checked the internals of the ecu and there was a piece in it that had been burned up so i picked up another turbo ecu swapped the pins on the harness and now it runs and drives great

I would like to thank everybody that posted on here with advice.