Rough idle, hard to start on cold starts, LAG

dregonomics

New Member
Ok so i have a 1990 acura integra LS with a jdm b20b 1997 with a p8r head.all stock. ecu throws no coolant temp sensor. when i try to start the car on a cold start i have to crank it for like 10 sec-15 nonstop before it will start..it may start and then die out shortly after.(starts up goes to 1500 then drops down slowly to shut off) also when i give it gas and i release while in neutral the rpms will drop all the way down to the first line like it wants to shut off but it wont.then it will slowly go back to around 6-700 sometimes it will stay low.car has some lag when i try to gun it.after i release the gas after i full throttle and put it in neutral it will die out and i have to restart it.it will turn back on normal..same goes for any time after its warm it will turn on like nothing is wrong.....

things i have done

Valve adjustment
New timing belt
Redid timing like 3 times
Cleaned IACV
New spark plugs
New spark plug wires
New Valve gasket set


not sure what else to check....
i am using the stock ls ecu...i also had a question regarding that
i read a few posts saying different things but the question is which ecu is best for my setup...stock jdm b20b with p8r head...i may be going b20 vtec LATER but i want to know the best ecu for my setup now....Thanks in advance for all your help.
 

g6qwerty

Member
My car has had a surging idle and it would go away as soon as it warmed up. Did you ajust the Fast Idle Thermo Valve (edit) yet? its on the under side of the throttle body bolted on with 2 10mm bolts and has 2 coolant lines running too it. on one side theirs a flat cover with 2 Philips holding it down, remove that and screw the white plastic down tighter with a flat head same way as a bolt. Its a thermal controlled Valve so that might be the problem.

Also had a problem where my car would want to die when warm, turned out i had a one way vacuum valve installed backwards. Check your vacuum lines.

I have a B20B in my 90 Integra Too. Not sure if the above will help you but the problem is in the idle control, Check your MAP Sensor too

From haynes Manuel for Integra 90-93
With the ignition key ON (Engine not running) Connect a volt meter Postive probe Yellow / Red wire and the negative probe to Green / White wire. (wiring harness side)
Their should be approximately 5 Volts
If not check the wireing or the PCM may be at fault
If 5 Volts connect the connector and back probe the connector with the postive to the White wire and negitive to the Green / White wire and thier should be now approximately 3 Volts with the ignition switch on.

Intake Air Temperature Sensor Resistance 1,000 to 4,000 ohms at room temperature.
 
Last edited:

BrokenTalon27

W.F.O
g6qwerty said:
My car has had a surging idle and it would go away as soon as it warmed up. Did you ajust the IACV yet? its on the under side of the throttle body bolted on with 2 10mm bolts and has 2 coolant lines running too it. on one side theirs a flat cover with 2 Philips holding it down, remove that and screw the white plastic down tighter with a flat head same way as a bolt. Its a thermal controlled Valve so that might be the problem..
Click to expand...
That isn't the IAC, that's the Fast Idle Thermo Valve you're describing. The Idle Air Control valve is on the back side of the IM and has 2 coolant lines and an electrical connector on it.
Also, when adjusting the FITV, screw the plunger all the way in then back it off 1/4 turn.
 

emd513

New Member
Check ur timing on the dizzy might need to retard it.had to do the same thing cause and if your head was shaved the original timing will not work
 


decision4life

New Member
I had the same problem with my jdm b20, it was the IAT and the MAP sensor and it was throwing my timing off because of it so I couldn't set my timing and I run a pr4 on mine
 

dregonomics

New Member
Ok thanks i will try all that tomorrow.i have to have my Distributor advanced just for my car to idle correctly...ive been told it needs to be replaced so im going to check it and test a new one tmrw..i dont have bent valves...but i will try eveyr thing you guys said tmrw.and will let u all know..thanks for your input.
 

dregonomics

New Member
ok its plugged in but i need to replace it cuz its still showing the CEL i got a new distributor and it seems to be fine.but one thing still persists....in the morning its a bit hard to start..but after that it will start fine every time.i will try some other things tmrw.
 

dregonomics

New Member
Ok new ECT SENSOR and seems to start up like a charm...now i just have to plug in my speed sensor and check out the wiring to the ECT i jumped on the freeway and the CEL for it came on again..i will try to fix it in a few min...car is still hot.
 
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