fuel injectors?

[88crwnvc]

my car idles kind of rough (at times extremely rough) at about 55 mph which is at about 1500 rpms. it makes the car seem kind of jerky like there is slack in the rear end, but i do not think this is the problem. could this be due to a bad injector? i've just recently pulled and changed all the plugs, after the problem started, and none of them were even remotely dirty, so this should mean that the injectors are fairly clean, correct?

but i was thinking if this is due to the injectors, i might as well replace them all, and if i'm going to do this, should i upgrade to larger 19 lb. injectors since i may want to do a HO conversion as soon as next summer?

just wondering what the problem is here and if it is worth upgrading..

[mrltd]

run some injector cleaner through it. Don't put 19 lb injectors on a lopo. Have you replaced the cap, rotor, and wires recently? Are they in good shape?

[Mikeri]

Listen up. I have an 89 T/C with 233k miles. All the injectors are original and CLEAN. I have tried everything, including the $55 dealorship clean job. Here is what works. There are 2 products that do a great job of cleaning injectors. If you are close to an oil change and you don't have alot of rust on your fuel lines, put Techron in your gas. At the end of that tank, change the oil. If you are not close to an oil change and you don't have rust on your fuel lines, put Marvel Mystery Oil in the gas. At some point, you will get a hurky jerky feel to the car. Don't worry, as this is the crud coming off the dirty injectors. ONce, clean, use MMO every 3 months to keep them clean. NOw, you should also check your spark plugs, wires, and coil. If they haven't been changed in years, you might want to swap them out. Boxes run for a very long time so don't be afraid to put a little dough into them.

[88crwnvc]

i put STP fuel injector cleaner in about every other tank, doesn't seem to help.. i replaced the plugs, but i did NOT replace the wires or the rotor and cap. what brand should i go with to replace and how much money is this going to set me back? i'll replace this if this is what is causing this horrible jerking motion.

[Nathan in MI]

As far as cap and rotor, brand isn't real critical, but spring for the cap with the brass contacts. It's a little more expensive than the aluminum contact cap, but it works better. I believe cap and rotor together when I bought them a month and a half ago were around $21.

As for the wires, I'd recommend something better than stock (i.e., lower resistance). You'll get a hotter spark out of them that way. What you want is nichrome core wires, not the carbon impregnated stuff. I put Bosch Premium wires on mine, and I've been real happy with them. Those were about $40. Their resistance is about 545 ohms per foot as opposed to about 3000 ohms per foot for stock wires.

[DarkKnight]

Umm, hows the tranny fluid look like? And have you thought of sea foam :-D

Also, have you checked ure u joints/drive shaft/Harmonic balancer? We had a work truck when it would get up to 55 it would shake like hell, turned out to be the harmonic balancer, sob flew off one day lator made a perfect hole... i was ^_^.. Any ways hope that helps mang :-D

[mrltd]

cap & rotor, about 25 bucks. Cheapo plug wires are about the same, and go up to about 50 for ford motorsport wires. Bosch or autolite are good for wires. Cap and rotor-accel and duralast gold are both good.

I would also suggest gettin the codes scanned by the local autoparts place. That will also help us diagnose the problem.

[88grandmarq]

first thing to do is a full tune up, this includes cap, rotor, wires, plugs fuel filter, PCV valve, grommet and screen.
check for vaccum leaks and check for stored trouble codes.