injector help

[Damian]

Im getting a misfire code, and Im having problems diagnosing the problem. Ive checked everything from the plug to the distributor and those are all good. The cat is good as well. The only other thing I can think of is the injector. How can I check it to see if its bad, going bad, or anything? Do I check resistance, voltage??

Also, I only throw the code if Im really pushing the car hard at high speeds, and I can feel it misfiring. Its only on cylinder #2, no other codes at all. This is an OEM injector in an Eclipse out of a Diamante. The Diamante has 275cc injectors, the Eclipse has 22cc injectors. The injectors are properly scaled and tuned for.

Thanks in advance.

[Vettezuki]

Im getting a misfire code, and Im having problems diagnosing the problem. Ive checked everything from the plug to the distributor and those are all good. The cat is good as well. The only other thing I can think of is the injector. How can I check it to see if its bad, going bad, or anything? Do I check resistance, voltage??

Also, I only throw the code if Im really pushing the car hard at high speeds, and I can feel it misfiring. Its only on cylinder #2, no other codes at all. This is an OEM injector in an Eclipse out of a Diamante. The Diamante has 275cc injectors, the Eclipse has 22cc injectors. The injectors are properly scaled and tuned for.

Thanks in advance.

Swap the misfiring cylinder injector to another cylinder and see if the misfire code follows the suspicious injector. :huh:

How many miles on the injectors? Did it ever sit for a long time? It might just have a little residue in the injector. Sometimes just running a can of Sea Foam with a tank of gas can be enough clean out injectors.

You ca also PM jsup of InjectorsPlus, he may be able to give you a technical test procedure.

[Damian]

I was hoping I didnt have to swap the injectors around since everything is such a tight fit. It sits for maybe 1 week tops, and Im not sure how many miles are on the injectors, but they are used.

The weird thing is though is I dont get any misfiring at normal driving, or even punching it on the on ramp. I only throw the code if I smash it at high speed on the freeway.

[Vettezuki]

I was hoping I didnt have to swap the injectors around since everything is such a tight fit. It sits for maybe 1 week tops, and Im not sure how many miles are on the injectors, but they are used.

The weird thing is though is I dont get any misfiring at normal driving, or even punching it on the on ramp. I only throw the code if I smash it at high speed on the freeway.


I'm not an expert on this, only making a kind of guess. The difference in these cases is that while you are at high speed (revs) you are also at a higher point in the duty cycle and *maybe* it's getting fatigued/hot and cuts out you stomp on it from there. :huh:

[Damian]

That was my thought, but at that rpms and throttle position, the ECU load is relatively the same, regardless of speed. Thats why this is such a pain in a$$ pinning down the problem. Ill pull the injector out later and inspect it, and swap it around with another one and see if the problem follows it. If it doesnt, seafoam it is. If it does, Ill get another injector.


Heres another question, if the injector is bad or faulty, wouldnt I get an injector related code along with a misfire code? I would think so, but I could be wrong.

[Vettezuki]

. . . Heres another question, if the injector is bad or faulty, wouldnt I get an injector related code along with a misfire code? I would think so, but I could be wrong.

Again, not an expert. However, I have an ODBII car that had a misfiring problem related to an injector that was intermittently working. There was no code at all, because the misfires were within tolerance apparently.

[Vettezuki]

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jsup may be able to help you test the injectors and provide a report. They can certainly rebuild your set (if they're rebuildable), or sell you a new set of flow matched injectors. BRIAN was pleased with the set he got for his Supra.

[Damian]

I sent him a pm.

[Damian]

Well, I figured out the problem. It was injector related, but not the actual injector. The rubber seat that the injector sits in somehow cracked off a small piece of rubber and was sucking in air. So once I get a new one, the car should run quite a bit better too.

[jsup]

Check for a bad ground. Seriously.... It's a real PIA but I suspect could be the culprit.