Hi all,

My friends 91 Firebird 3.1 broke down a couple of weeks ago on his way home out of the blue, it started jerking and losing power if you went anywhere near the throttle so he pulled over and with the car just sitting idiling the rpms were going up and down and up and down, then if you tried setting off it would just cut out. So it went home on a tow truck

the mechanic had a check over trying to fix it at the side of the road and he said it was missing on one cylinder and noticed a few of the leads were well past it, so my friend ordered new plugs, leads, cap and rotor arm and i changed them for him

the plugs were the worst ive ever seen, i had to actually spray WD40 on them to get them loose ! anyway, changed it all over and started it up and it was doing the same damn thing for a while, but after it warmed up and possibly burnt off any remaining crap from getting the old plugs out it was totally fine, we drove it around for 30 minutes and it never missed a beat.

The car continued to be fine all last week as he used it every day, then last night coming home it started doing the same thing :/ jerking around losing power, nothing much happening when accelerating, he managed to nurse the car home and he said it was idiling irratically on the driveway again.

Sooooo........... any ideas ? i cant see if his SES light is on because of the KITT dash which doesnt help.

 

If the engine still has the OEM Multec injectors, replace them.

RBob.

 

THIS!

The problems you're describing are the exact symptoms my 91 Firebird had when the injectors started to short out. The GM Multec injectors are notorious for shorting out, you can find information all over the web about it. I had my car in the shop at least 5 times and most of the time the car would run fine for them but when it did start acting up they tried replacing some things and thought they fixed it but then it would happen again. Eventually after some research I found out about the injector issue and replaced them with some reconditioned Bosch DRI injectors from Linder (http://www.lindertech.com/reconinj.htm). That was over 4 years ago and the car hasn't had any problems since then plus the Bosch DRI injectors from Linder have a limited lifetime warranty.

 

hmmmmmm i will let him know then thanks guys. It looks like the car hasnt been that well maintained over its life judging by the state the spark plugs were in when i got them out so id be fairly certain to say its still got its original injectors

 

crank sencer

 

We call the crank sensor "the distributor."

RBob.

 

i was just gonna say, what the hell is a crank sensor

 

X2

Thats a foreign object to us RWD v6ers, lol. Unless we have turned to the hybrid darkside, lmao

 

hybrid isnt the darkside..lol V8 are or selling a camaro for a ford

 

Good point. My Camaro will never be sold, and will never have a V8

 

I had a similar situation happen to my 91 RS with the 305. Replaced every sensor and relay we could think of chasing the problem. Finally replaced the fuel filter and checked the fuel pressure and found it to be extremely low and erratic. Turns out it was the fuel pump all along. Had it replaced for about $175 and has run perfect ever since. A bad pump can cause you to chase gremlins for along time. I would check the fuel pressure before replacing any more parts.