Fuel Injectors

[Aaron98Disco]

Typically at what milage do these guys need replacing? I noticed symptoms in my 1998 DI (GEMS) That could be these fellas or possibly oxygen sensors. e.g. worse than usual fuel economy, power loss on accel, and occasional petrol smell in the cockpit (which leads me to think injectors.. But... She starts fine.. Idles normal). Truck has 52K.

[Disco Mike]

Two things will kill fuel injectors, pollution like rust and old age seal failure.
%@K is not enough mileage to cause you a problem. When was the last time you replaced your fuel filter, how about a good fuel additive and a induction cleaning? You still running the originial plug wires, thats a killer?
Mike

[jhmover]

Run a jug of Techron thru it before you start buying stuff. It works sometimes. I had a 88 GMC that had the fuel injector plugged. You would take off from a standstill and it would about throw you through the windshield then grab and take off. I had to go to Reno on business. I put a large jug of that in, filled it up with the good gas. By the time I got to Reno it was about 1/2 as bad, by the time I got back to the Bay Area the hesitation was gone completely.

[Aaron98Disco]

Thanks for the replies guys! New Champion plugs & plug wires were put in about 2k ago. Never ran a fuel additive in her though.. always used premium gas. Sort of relied on what was in the premium. but I'll go get some to dump in the tank today. & good call on the fuel filter.. forgot all about that thing.

[Disco Mike]

You can use a number of gas additives to try and clean injectors, some work some don't, but they won't clean out hard material that has by pased a plugged up fuel filter.
I would suggest you change out you filter first then use some Techtron, B&G 44K or SeaFoam over the next 2 tanks of gas.
Mike

[Rovin4life]

to tell if a fuel injector is bad check fuel pressure and start it up and then let shut it off to see if there is any leakage. it should stay put after thirty minutes

if you have a fast drop you have a leak in the system. doesnt mean its the injectors it just means fuel pressure leak which will cause misfires. you need to then clamp off the lines and check for leak down, if no leak down its the pump but if there is then its the injectors. Usually the misfire code will pinpoint that. if not take them out and test them individually by watching the spray pattern.

if its a complete failure on that cylinder use a noid lite to see if its got power if that is good then make sure you have fuel pressure and put twelve volts to the injector and then it should drop.

[Adam in NYC USA]

Originally Posted by Aaron98Disco

Typically at what milage do these guys need replacing? I noticed symptoms in my 1998 DI (GEMS) That could be these fellas or possibly oxygen sensors. e.g. worse than usual fuel economy, power loss on accel, and occasional petrol smell in the cockpit (which leads me to think injectors.. But... She starts fine.. Idles normal). Truck has 52K.

Your signs & symptoms sound more like your oxygen sensors. GEMS usually start off rich when you reset the ECU then take a few miles before it likes the readings off the oxy sensors. The firmwire was written for the older slow-acting oxy sensors not the quick acting ones made today.

Start with the Techron. If still having problems, then let us know.

BTW, that gas smell is always going to be there when you cold-start. After it warms up, the smell is usually gone. The ECU puts plenty of fuel in the cylinders so you can start up. Ever notice that it just starts up right away? Some Fords and Mitsus you have to crank first then it starts on the second.

It actually counts up to three cranks so it sees the sensors and everything is primed.