CRX B20b Needs Help

existanzcivicb20

New Member
Ok 1990 CRX SI swapped a b20b using a p28 chipped, using stock CRX fuel rail and injectors car starts with no problem but then dies a few moments later. No Cel codes. I've tried swapping TPS, smoked the intake manifold for leaks, new grounds, 3 map sensors

when i start the car it idles at about 500 RPMs and if I try hitting the accelerator it dies. If I disconnect the map sensor the car turns on with no problem and idles perfectly but if I try hitting the accelerator it bogs out and dies. Please watch videos for reference. Fuel pressure is at about 28psi at idle with the vacuum line connected to the FPR and 38psi disconnected

 

existanzcivicb20

New Member
Thank you for the reply and I am not replacing parts at random I am trying parts that appear to be involved with my issue and its all parts that I have spares of. New swap and I have also tried a known working OBD1 LS ECU and the car behaves the same with no change no codes. I still feel like its a sensor problem.
 

existanzcivicb20

New Member
Random guesses^^

Do diagnostics instead.

I have checked voltage to the TPS (5 v and 0.5 v into the ECU) also voltage to the MAP sensor ( 5 v) voltage to the IACV is 12 v and I do get a nice blue spark with 160 psi across all cylinders. All I have to go by are the symptoms of the car. Please let me know if you can think of anything else I should check. sorry i didnt feel like listing them before.





Did you do the engine swap? Yes I did You most likely swapped some sensor connectors. Check them carefully one by one using wire colors as a guide. The only connectors that I can think of that might have gotten swapped are the MAP with TPS and also the IAT with IACV and this have been checked and verified with the wire colors. Can you think of any others?

Does the CEL work? Yes it does I get the CEL light on when I disconnect the MAP sensor



You'll get better help by answering questions. Done.
 


existanzcivicb20

New Member
As I mentioned earlier I am using a known good OBD1 LS ECU, Also I got the engine from a shop that sells imported engines. Plugs and Injectors are connected in the correct order. The distributor will only fit one way cant be off 180 degrees.

I switched the ground wire and power wire on the TPS (so now the signal goes from 5 v at close throttle to .5 v open throttle) just to get the car running. it idles perfectly but very rich obviously and runs strong up until full throttle. Only reason I did this was to get me to work 10 miles from home.

I will post the colors of every connector later when i get home. Also my timing light just arrived yesterday but havent checked the timing I will do that also
 
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existanzcivicb20

New Member
Yes the distributor is aftermarket and I have tried and tried to make it fit after spinning the rotor 180 and won't fit. After testing the timing with the timing light at 0 degrees and the distributor all the way forward (away from the firewall, because it runs best this way) the timing mark does not line up. The mark on the harmonic balancer falls a little ahead ( towards the front of the car) if I set the timing light to 90 degrees the mark line up perfectly
 

existanzcivicb20

New Member
Sounds good, but it's well known that some aftermarket distributors can be installed 180-degrees out of phase.



^Important information is missing

To meaningfully check the ignition timing, the engine must be fully warmed up and idling to spec, and the service connector must be jumped.

Which timing mark are you referring to?
Engine was at operating temp and service connector jumped. The mark is the single mark not the 3 marks
 

existanzcivicb20

New Member
Update I checked timing and it is dead on. I installed a new MAP sensor again and now the car runs great no cel codes. When driving down the road no issues but if I hit full throttle Cel comes on with code 3 and the car dies when I let of the gas.
 


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