sonu1975

My camaro 91 3.1L (5-speed) jerks when I push the gas on any gear while on idle it runs just fine.
I have changed the distributor cap and rotor since they were falty and I havealso changed the ignition coil. It runs much better than before but still not 100%.
I heard that it can be my fuel injectors which are clogged or might even getting bad so I thought that I would replace them.

- Does anyone have a step-by-step instruction on how to replace them (preferably in video) ?

- Can there be any other fault ?

Maverick H1L

iTrader: (8)

If you're serious about just yanking and replacing the injectors, it's this simple:
1. Undo the clamp on the intake bellows and remove from throttle body and intake.
2. Undo the clips holding the throttle cable, transmission cable, and the cruise control cable (if equipped with auto and/or cruise) from the TB lever. Remove cables and put 2 clips back on the posts for the throttle and cruise cables so they don't end up AWOL.
3. Remove bolt holding throttle cable bracket to upper plenum.
4. Remove bolts holding TB to upper plenum and bend forward on the coolant hoses.
5. Remove bolts holding EGR transfer tube to upper plenum.
6. Label and remove vacuum hoses from back of upper plenum.
7. Remove 10 bolts holding plenum to lower plenum and move plenum aside where you won't knock it around and/or drop it.
8. Remove locking clip, if installed, from the injector harness connector and unplug Also unplug coolant temp sensor.
9. Remove bolt holding fuel line clip to engine lifting bracket.
10. Grab a rag and a screwdriver. Remove black or silver cap from fuel pressure test port in rear of fuel rail log. Put screwdriver tip into port, wrap rag around port and screwdriver, and push down on screwdriver to release fuel pressure. Hold for about 10 seconds and release. Set rag down where it can't eat the paint.
11. Remove nut holding fuel accumulator to lower intake. Lift off of support bolt.
12. Remove 2 bolts holding fuel rail to lower plenum.
13. Put a screwdriver between fuel rail and lower plenum, and lift up. Screwdriver required because injector o-rings are probably stuck in the bores and hard to remove.
14. Twist fuel rail around until it's over one of the battery trays. Flip over as hoses allow. Put a rag underneath to catch gas that will leak out of injector bores.
15. Unplug injector connectors from injectors by squeezing clips towards injector body and pushing or pulling connector away from injector.
16. Locate tabs on injector lock rings. Using screwdriver, push towards the opposite end of the fuel rail from where it is now. Pull injector out once done.

Reassembly is the reverse. Be sure to replace any damaged gaskets and injector o-rings if new injectors don't come with new. Oil o-rings before installation. Before you put the upper plenum back on, put the cap back on the fuel pressure test port, if you haven't already, and prime the fuel system. Make sure no injectors or anything else leak. Test the resistance of each replacement injector before installation. Any injector measuring below 11.8 ohms is automatically junk. Also inspect the harness when you have everything apart to make sure no critters had lunch on your wires.

Have you replaced the fuel filter and/or tested the fuel pressure yet? Being in gear means the engine requires more fuel than just at idle, and if the fuel system between the tank and engine can't compensate, the engine will run like garbage.

sonu1975

Thanks a lot for the info Maverick

sonu1975

I have changed my injectors and fuel filter. 2 of the injectors were bad (5 ohm and 9.9 ohm). The car runs much better but still sometimes it jerks minutely while accelerating.
I don't have a fuel pressure kit so I cannot check the pressure and I the fuel regulator has not been replaced.

Any ideas what it can be ? ignition problem ?

Maverick H1L

iTrader: (8)

Can't tell until:
A, you drive it more and then pull the spark plugs out to note their color on the cylinder end (when the engine is cold, of course), and
B, you get a fuel pressure reading.

Or just get a new set of plugs and wires and then go from there... If the cap/rotor and other ignition parts were junk, those probably are as well.

sonu1975

I had changed dist. cap, rotor, wires, plugs but it seemed that the cap was faulty. I will change the plugs n wires n go from there.

Y-day i was driving and i changed the gear from 2:nd to neutral and stopped at red light and the car stalled. It has happened once or twice before. Can it be the TPS sensor, ignition coil, fuel pressure regulator?

SandmanSS

is there any re-priming or anything necessary after replacing the injectors?

fasteddi

iTrader: (2)

The pump will prime when you turn the key on but in a non start state. As the car is trying to start the injectors will open and close purging out the air and letting the fuel fill everything back up. SO if you notice it takes a bit more cranking the first start up thats why.