89 ROCKINGFLAME

My 1989 Firebird is driving me nuts !!!! Fix one thing,another breaks !! I guess that's what happens with old cars. It has a 305 TBI engine and 700R4 transmission. Anyway, straight to the point. Bought the car 6 months ago, ran well for a while.Excellent idle,good power.Starter crapped out, replaced with a new one.Everything good up to there. Found out "resistor pellet " in key had been bypassed with two resistors. I then started shifting from DRIVE at takeoff , car was kind of slow at take off,and then shifting back to DRIVE OD after the car was at 50mph or more on the highway. All of a sudden one day it shut off on me while I was driving, I put it back in NEUTRAL, turned the key , car started right up and kept on going. A couple of days later it did it again,but as long as I kept the car in DRIVE OD, it would not shut off on the road. One day it just shut off and didn't want to start. I found the distributor cap totally loose and found that both screws that secure it in place had broken off. I took the cap off,pulled the dizzy and put new screws in, put everything back in place and the car started right up.Took it out for a spin,everything good,but an hour later I took it for another spin and shifted from DRIVE to DRIVE OD and it crapped out again. This time, it tried to start,sputtered,and shut off. Had it towed home. Checked to see if there were any loose connections,couldn't find any. Oh and BTW, I did the jumper thing to check the codes and the only code was the 12 code .At key-on,engine off,the security light comes on and goes off in 3 or 4 seconds. So everything seems normal up to that point. I put in a new Neutral Safety Switch because I would wiggle it and the car would not crank every time. Car cranks all the time ok now, I srayed STARTER FLUID down the TBI and it starts , but dies immediately. I checked the voltage at the ECM on the DARK BLUE wire and it was 2.5 vdc with the key on, engine off position. There is no strong gas smell at the TBI. What could be the problem ??? Maybe the fuel pump relay, fuel pump itself, the oil sending unit ??? How can I check these ??? My Haynes book wiring diagrams don't tell me much about these circuits. Any help would be great appreciated or I'm gonna burn this car up !!!!! Sorry I made the thread so long, but had to include all the checks that I have done ( picked them up here on the forum from the experts !!! )

1gary

And the fuel pressure is??.

NagleMac

iTrader: (1)

Sounds like you got a bunch of problems, but that's ok, cuz I'm in the same boat as you, it could be low fuel pressure, maybe clogged fuel filter, or it could have nothing to do with the fuel

UnderCover89TBI

iTrader: (25)

well if its cranking its not a vats problem. to be so intermittent its possible you have a loose ground on the back of your cylinder heads. possible bad ignition control module as it does correlate with the injector pulse also. im my opinion. but you typed so much information its really hard to read it all and get it all.

89 ROCKINGFLAME

I can't here the fuel pump when I turn to key to key on/engine off position. I'm gonna check to see if there is voltage on the connector going to the fuel pump right next to the fuel tank since I don't know which pins are what on the fuel pump relay.

89 ROCKINGFLAME

I can't here the fuel pump on when I put the key in KOEO position. Will check to see if there is voltage to fuel pump connector next to tank.

89 ROCKINGFLAME

will check voltage going to fuel pump at connector next to fuel tank. I've heard that if they used splices when you replace the pump ( and I know it was replaced last year with a BOSCH pump ), that might be the problem. Wish me luck.

89 ROCKINGFLAME

Thanks for all those great opinions. Will definetly check those ground straps from the cylinder heads to firewall. They are kinda hard to find back there. will keep you posted. Sorry for putting so much info in my original thread, but I was trying to put in all the details of whats happening.

89 ROCKINGFLAME

I just found this great site looking for info on the ECM that I found installed in my car, which might not be the exact match, but supposedly works. Anyway, this site has ALL the schematics for my car showing ALL the signals from ECM to anywhere it connects to. Pin numbers,voltages,wire colors, everything.I'm sure it will be of great help. It also has info for many other ECM units that might be compatible. Check it out. It is...http://www.diy-efi.org/gmecm/ecm_info/1227747/..... from there just look up your ECM number. Mine is 1227747, used on GM light duty trucks between 1987 and 1991 with engines 4.3L V6, 5L V8, 5.7L V8 and 7.4L V8 with automatic or manual transmissions. I guess you can use this ECM 1228747 on an 89 TBI Firebird and so you need to physically look at that white label on the computer and get that info when you have a problem. BTW, this should help me to find that FUEL issue that I have.Does anybody know if this ECM ( 1227747 ) will work fine in my 89 Firebird ??? or maybe this engine was swapped with a 1991 light chevy truck engine. That would be funny !!!

89 ROCKINGFLAME

First of all, I found that the fuel filter had been moved to a spot under the floor pan beneath the drivers seat !!!! It's been spliced in the fuel line with a rubber hose and some clamps. This rubber hose looks like its kinked at a bend that was put in there when somebody installed it. I'll probably disconnect the rubber hose on the inlet side of the filter, then turn the switch and see if some fuel comes out . Should give me some indication of the FUEL PUMP condition. Still might have to check the voltage going to the pump on the aft connector to the PUMP, or maybe even putting 12 volts straight into the connector to see if the pump is still alive. Keep ya posted !!!!