When i first start the car after its been sitting for a long period of time generally over night runs perfect but after about 5 minutes limp mode kicks in ive tried several times checking for codes and Nothing cel light comes up after those 5 minutes while driving it. Its a 94 gsr head obd1 ive researched limp mode for countless hours and havent havent found any problem like mines also does it matter since my car is a 99 and engine is obd1 could that be a reason of no codes when jumping the two wires

 

Does your check engine light work?

 

Yes it does i noticed today that it the cel kicks in once it reaches normal operating temperature
Its has a p72 chipped no o2 sensor but used to run fine before until recently

 

Pull the code with the car running next time it comes on

 

Fuel pressure problem

 

Limp mode with no CEL code (meaning solid CEL) means a bad ECU or bad chipping job. It could be intermittent due to a cold solder joint or just a spot that has excessive solder blobs around it. The last ecu that I repaired had a decent looking joint on the octal latch (smaller chip) yet the desolder job had burned the trace just next to the solder that caused it to throw a constant solid CEL.

The best thing to try is a different ECU, after that you'd want to re-burn the map to a different chip. Chips usually fail completely, not intermittently, but there's a chance.

 

You can still pull codes even if its an obd1 ecu, jump the 2 pin plug near the ecu, should be above the ecu, and your cel light should blink. If you can't decipher it please post video.