supamaro383

so it took me since march to get my car to run correct.... so today i ran it on the freeway so it did fine for 20 mins... but now its flashing check engine light ...... poping sounds every time i let the throttle go..... if i give it heavy throttle the check engine light stops flashing.... so i stop unplug my ecu for bout 5 min the turn it on no flashing ecu....onec agian 20 min later lights stars flashing...
oh ya I check 4 codes nothing but 12...... - speed destiny - 91 camaro rs - t5
-383
-first fuel injection
-305tbi to 383tpi conveted harness (tpiparts.net)
-knock senser change to 350
-ecu 7730 (affodablefuelinjection.com)
- tps/iac set calb and in specs
-fuel press @43psi..... @50psi wot
- 24lb ford injectersaffodablefuelinjection.com. -8 degrees BTDC
-all grounds check
- all new senser except dizzy........ was change a two years before the conversion

cant think of anything else @ this time but please help me b4 i blow this car up!!!!!!!!!!!!!! thanks

supamaro383

well I guess this is a hard one..... at least can someone tell me when the check engien blinks real fast means?

sharpx

i'm not an expert but maybe you forgot to pull the jumper out of ALDL connector (for flashing codes) - with the engine running flashing fast means you're in open loop (like 2 or 3 flashes per second) as opposed to closed loop where you get 1 flash every couple a seconds or so (seen this in another post and tried it yesterday)

EDIT: I re-read your post and what i assumed doesn't make sense - i guess i don't know.

ASE doc

Yep. Sounds like your ECM is stuck in diagnostic mode.

supamaro383

I browwerd the ecu from my 92 and change the prom and now the car works like a champ. so I guess the ecu is bad.

ASE doc

Be sure to check circuit 451. It should go from pin B of the ALDL to pin A9 of the ECM. If this circuit is shorted to ground, the ECM will stay in diag mode.

supamaro383

so I have been driving my car all day and it has been driving very well so I'm going to say it was a bad ecu. I talk to affordable fuel injection their going to send me a new ecu for free. so I'm gald this was a easy fix. I was wondering if anyone has done a tbi to tpi swap and notice that the rmp gage is off. do I need a tpi dash? aslo it is surging a littel like 200 rmp up & down. is that normal?

ASE doc

Hmm. The surging and inaccurate tach could be related. The issue may be in your ignition module. However, inaccurate tachs are common on these cars. The surging can also be caused by a slightly lean fuel mixture. Check TPS adjustment and fuel pressure. Check for vacuum leaks.

sharpx

when i had a surging issue it was the MAF sensor but i had a code that pointed to that one - do you get a check engine light, if yes pull your codes and see what it says

Gumby

If its a constant almost strobe like flashing SES light, that means it can't read the chip in the ECM or the ECM is bad or probably both.

Had to replace both to get mine right when I had that.