Ok I bought a 1991 Camaro RS and it drove fine for the first month. now the dash lights wont turn on and it keeps blowing fuses, and now the second problem! The car it running rough and I noticed it is spraying fine one injector but the other is a broken funnel. but now when I disconnect the MAP sen it idles fine but loses vacuum and die when try to give more gas. With it plugged in the timing jumps from 0 to 8 digress, and also back fire through the TBI. could someone please help me i dont even know where to start anymore. I replaced all I thought it could be and nothing yet.

 

I think you may have seperate issues. Start with the basics.

1) Fuses - I know, but check them again. Did you check the one by the battery under the hood?

2) Backfire - this usually happens with a spark issue, not a gas issue. Check all plug wires - make sure they are all on the plugs all the way (I had one pop slightly off causing a backfire). Double check firing order again. Get an OHM meter and check continuity on all plug wires - even brand new ones have shorts in them.

3) Map Sensor - just replace it - it's not much.

4) Vacuum - bad vacuum can cause alot of issues. Check ALL the vacuum lines everywhere, and replace any that look like anything but brand new.

5) make sure the EST is not unplugged - this is a brownish wire on pass side that you unplug to set base timing - it's the Electronic Spark Timing signal wire that retards/advances distributor.

6) The dash lights - you must have a short somewhere - PITA, but the only way is to start tracing wires, looking for hot spots or any place that any wire may be touching a ground or another wire.

Again, start with basics - everyone (including myself) wants to makes things more complicated that what they really are.

Good luck!

 

thank you for your help. the map sensor was replaced 2 times and still has the same problems, but I'm thinking about the vacuum which might cause that also if I'm not mistaken. thank you once again!

 

i had a problem very similar to this, it turned out i needed a new idle control valve and one of my vacuum tubes was broken open, then the car was running rough and losing power but that was from the bad alternator