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I haven't completely given up on this yet

Well, the only thing I got to do was pull the injector connectors while it was running.There was no change in engine idle when I pulled injector connector 2,4, and 5. I guess I need to check for spark on those cylinders now.

Would it be worth it to attempt to have these cleaned? Or should I just get 8 new injectors (I don't know how I'd feel if I just changed the 3)?
 
I also just checked the resistance of each injector (while they're still in the fuel rail, not sure if that makes a difference) and they each had 15.3 ohms. According to what I've seen with Accel, and other manufacturers, the ohms should be 14.4, but they don't give any variations in tolerances.
 
Lower resistance is bad. Higher is fine.

If those are the factory GM injectors, they are garbage.

Not sure what rebuilt units vs new are running, but I'd suggest contacting this guy http://www.mrinjector.us/contact-us.html

Dealt with him in the past, very professional. Used to be the Ford SVO's were the cool swap, but they disco'd those and I don't know which of the more modern variants you should use.
 
These are a set of Accel injectors I got about 9 years ago when I started piecing this together.
 
After checking for spark on those 3 cylinders, is there anything else I need to look at (if I'm getting spark to those cylinders) before determining that those injectors are my problem?

I'm still deciding on what ALDL cable to get. I PM'd that guy on gearheadefi and am waiting on a reply from him. Once I get tunerpro all set up is like to post up all my data from data logging to see what y'all think.
 
Accel injectors had a BUNCH of problems back in the day. I'm honestly surprised yours lasted this long. Not much we as the layperson can do as a test to see if they are good other than check resistance, but that only tells you what kind of shape the coils are in...says nothing about pintle condition, etc.

I'm not saying replace them, that's a pretty big, expensive job, but that would be in the back of my mind.

You are saying that you know for certain that 2,4, and 5 have some sort of issue, the engine ran worse when you unplugged each of the remaining cylinders? If you've got the length (or a spare or two) you could try different plug wires. I had a terminal separate in the boot before.
 
Either you or Mark told me awhile back that Accel had a bunch of problems. Ever since then, if I have an issue with fuel, I always suspect it could be the injectors.

And correct, when I disconnect injectors 2,4, and 5 there is absolutely no change in engine idle that a can hear or feel. When I disconnect the others it starts to run terrible.

The wires are fairly new, I got the 25' roll of MSD wire and the boots and terminals and made them myself. I don't have any extras to check with though.
 
I made my own (out of Accel stuff lol) and thats where i had the crimp fail in the boot. Probably my own fault, but just an idea of what can happen.

Would have liked to get a group buy on plug wire components, to really save money you need to buy a bunch. :)

Anyway, you know those cylinders are the issue, need to figure out why. If not spark, it has to be the injector. Outside of a severe mechanical issue. I broke a rocker arm stud once. But that caused other symptoms anyway.
 
I'm going to check for spark when I get home later (if it's not raining). I think I have an extra spark plug laying around somewhere I can use. I could get my wife to hold the end of the wire for me, but I'd probably only get one tested that way. :popcorn:
 
Lucky for me last time I was checking spark on mine, it was on the drivers side and I have a metal bracket over there. Vise-gripped a spare plug to the bracket, ran the wire to it, no shock. :)

It doesn't hurt, I just hate it.
 
Ok, I just checked for spark on those 3 cylinders and I definitely have good blue spark on them. I shouldn't have joked about shocking my wife earlier though, I had the plug laid across the valve cover and I couldn't see it. So I grabbed the boot and I got shocked... :doah:

Sooo, that leaves the injectors or a valve not opening for some reason, right?

I'm really surprised at how well it runs on 5 cylinders, I would have never thought it wasn't running on all 8.
 
TPI does a real good job running under terrible conditions. Mine ran (not good, but ran) at 25PSI. Funny, sometimes that makes it hard to see the problem. Could pull a plug wire or two and it would not run worse that I could tell.

So you pulled and tested each plug? I've broken them before (on install) and not noticed. They are a lot more fragile than I used to think.

I wouldn't say valve not opening, if an intake valve doesn't open, you'll pull oil past the rings, that will burn and create a ton of smoke, the runner will fill with fuel, it will run ridiculously rich as that fuel is pulled into the other runners, and should trigger a CEL for rich condition.

I'd expect bad compression first, but not on three cylinders if the motor is in decent shape. That would be incredibly coincidental to have three drop compression at once.
 
I didn't pull each plug today to check, but I had them out 7 days ago when they were fouled out. I probably need to replace them though. I just hit them with a wire wheel, sprayed them down with brake cleaner, and reinstalled them. Does it need copper plugs, or something like platnums?
 
Run straight up AC Delco's. Whatever are correct for the heads you have.

I don't replace plugs unless I know they are bad, or they are worn to the point they don't work. Throwing money away IMO. If I was going to get that deep into it, I'd swap a bad cylinder with a good one to see if the problem follows the plug.
 
All I run is AC delco plugs.

I'll swap my plugs around tomorrow and report back
 
I just moved all my plugs around and the same cylinders still aren't firing. So that eliminates them. I also re-checked all the injectors with a noid light, and they are all getting a pulse. So for fun I pulled my valve cover and pulled the bank 1 and 2 injector fuses and had my wife turn it over while I was watching the rockers. They all are working, so no broken studs, pushrods, etc.

So that just leaves the injectors, right? I would move them around to make sure the dead cylinder moved with them, but as you know, that involves taking the intake apart, and I don't feel like getting a bunch of sets of intake gaskets just to move injectors around.

I guess that brings up this question, If you were replacing your injectors today, which ones would you go with, without breaking the bank? I'm not going with Accel again, even though they're the cheapest at $275 for 8. Any thoughts on the trickflow injectors?
Should I go back in with 24lb injectors (even though I'm not sure if my PROM is burned for them) or should I find 22lb injectors, like a stock 350 should have?

Or am I jumping the gun and there's something else that I need to check before replacing the injectors?

*edit* Right now I'm looking at SouthBay Fuel Injectors, and they have remaned 22lb bosch D3 injectors for $166. They also have the same injectors that are 24lb for $170.
That's about the same price I could get mine cleaned for, and maybe they'll work then.
 
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If you can wait, see if anyone else has any ideas just to make sure. But if the cylinder is getting spark, you are CERTAIN idle does not change when those particular cylinders are disconnected, I don't see what else it can be.

As to what injectors to run, I don't think there are many manufacturers. I can't help with who does remans good, but I've dealt with mrinjector before, and he was a stand-up guy. That I can say, and that goes a long way with me. I doubt you'll find a huge difference in prices, but if you do, it might be depending on how in-depth they go.

You really want to know what injectors your programming is for. Better to be too rich than too lean of course, and if its setup for 24 and you give it 22's, it will run lean. Conversely, if the tune is good, 24's will be rich.

Can whoever provided you the chip give you specs on it? Only way I know to pull the info is to use something like Moates sells, so you can read the chip. Easier to ask the chip burner what they did. What are you running now? If it ran good for years with those, run the same lb/hr IMO.
 
I can wait, hell, it hasn't run right since February...

I know that with it running, I can grab the #2 and #4 primary and hold onto it without getting burned. But if I just touch the #6 with the back of my hand it gets burned. That's with it only running for a few minutes prior though.

Ever since I've done the swap it's had these 24lb injectors in it. I can call Street and Performance tomorrow to see if they have any info on my tune, they tuned my PROM chip. Last time I called them (to get a schematic for their wiring harness) they said they had no record of me in their system.

It ran good, but has always run a little rich from what I could tell/smell. Even if the injectors fix my problems, I'm still going to get an ALDL cable so I can data log it. Might as well be able to see exactly what's going on with the engine if I'm going to keep the TPI.
 
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