Slade1

LO3 TBI

About a few days ago, I noticed my car acting strange on the highway. There was an odd vibration at certain rpms while cruising at a steady speed. It happened consistently at those rpms and the vibration was intermittent at the same interval.

I went through the fluids, eliminated the drivetrain from the equation. (Put car in neutral at those same highway speeds and revved the car in idle and noticed the car was vibrating even in idle at those same rpms)

I looked at my injectors as they fired and notice the cone spray to be "different" than usual. Still a cone shape, but not as elegant as I could last recall.

Today I whipped up an ALDL cable and tested it out. I've got BLM counts from 128 to 141 at various rpms/speeds.

Am I right in saying that the BLM count is going up because the fuel pressure is weak?

Things I should be looking at are my injectors, fuel filter, fuel lines and fuel pump?

My guess is that my filter is clogged bad. The filter and pump are 2 years old. Injectors are 15 years old like the rest of the car. I doubt the pump would have gone bad after 2 years only. The stock one laster 13 years after all.

I'm leaning to the fuel filter as it is a cheap generic brand. I have a replacement already waiting to go in. I just need a break in a bit warmer weather to get under and replace it.

If the injectors are firing at those high rates, would they suffer any kind of damage to them? Am I still able to drive like this without risking damage to the injectors. I've jumped my fuel pressure up via the regulator to help and backed off my timing to stock to help out my fuel starved engine, and it seems to have helped in the mean time. I need a car, I just want to know if I risk loosing my injectors.

Vader

What's the standing fuel pressure?

As long as the injectors aren't going static for long periods of time, you probably aren't doing any damage. Undervoltage from poor electrical connections would probably do more harm than long pulse rates.

Slade1

I would imagine the fp to be weak, I don't have a guage in the car, but from the weak spray pattern and the high blm counts, definitly not enough to feed it.

I also had a hard time starting it at work today. Took a few tries to get it going. I don't imagine I have much time left with conditions the way they are.

I pulled plugs today to confirm the condition. They are still brown/tan colored but there are indications that it they have experienced running lean.

Steve89GTA

Gotta get a fuel guage on there. I got mine for 80 bucks canadian shipped to my door - brand new accel that goes onto the fuel rail. When you prime it, you'll instantly see if you're getting the pressure you need. TBI is different than my TPI though, so I don't exactly know the steps to isolate each part. Basically, it's either the check valve in the pump, weak pump, clogged fuel filter or clogged/weak injectors. Injectors sound like a good culprit especially considering the age.