#2 Misfire at Idle, Random/Multi While Driving

[boy&hisdogs]

So I installed the new distributor, got it adjusted to +0.8 degrees at 1000-1200 rpms and it ran really well just idling there in the driveway. Super smooth, couldnt feel a miss and no check engine light. I let it sit and idle for about 10 minutes or so and right before I got in it to test drive it started missing again. It felt the same as before and gave the same #2 misfire code. It flashes while driving around still but my scanner isn't actually picking up the random/multi code.

Before buying a new dist I tried to adjust my old one. Couldn't get it anywhere close to spec, best I could do was -8. Thats as far as I was able to rotate it before hitting the plug wires against the air box. I got a new scanner and app (Torque Pro) and I'm able to monitor each individual cylinder for misses. With the old dist I was getting misses mostly on 1 and 2, and a few others here and there. Now it's zero everywhere else but still missing on 1 and 2. 2 has wayyyy more "historical" misses but 1 has fluctuating "current" misses.

 

[boy&hisdogs]

Finally got the injector testing tools, one of them is completely unresponsive. I'm not sure how accurate the diagram I found is, but there's definitely a dead injector somewhere in that engine. It doesn't really matter which one I guess since they all get replaced together.

Seems like everyone is out of stock of the AC Delco injectors, Summit is the only site that let me order them and they say it'll be 2+ weeks. Amazon won't even send me injectors right now because apparently they cause cancer in California. I guess I just need to move to Nevada so I can stay cancer-free and die peacefully of old age.

 

[stutaeng]

Finally got the injector testing tools, one of them is completely unresponsive. I'm not sure how accurate the diagram I found is, but there's definitely a dead injector somewhere in that engine. It doesn't really matter which one I guess since they all get replaced together.

Seems like everyone is out of stock of the AC Delco injectors, Summit is the only site that let me order them and they say it'll be 2+ weeks. Amazon won't even send me injectors right now because apparently they cause cancer in California. I guess I just need to move to Nevada so I can stay cancer-free and die peacefully of old age.

This is a daily driver I'm guessing? 2 weeks to them?

I think it's been discussed that "it appears" most or all of mpfi injector assemblies are the same, just rebranded differently? They have the little green tips on the injectors.

The one I bought was the BWD from Advanced Auto, but I wouldn't hesitate to use a common name brand spider in a pinch.

Is RockAuto an option for you? I believe they do sell individual injectors now, both the CPI and mpfi.

 

[boy&hisdogs]

This is a daily driver I'm guessing? 2 weeks to them?

I think it's been discussed that "it appears" most or all of mpfi injector assemblies are the same, just rebranded differently? They have the little green tips on the injectors.

The one I bought was the BWD from Advanced Auto, but I wouldn't hesitate to use a common name brand spider in a pinch.

Is RockAuto an option for you? I believe they do sell individual injectors now, both the CPI and mpfi.

I've heard it can be hit and miss with the no-name ones. Some people say that they got a good one, some people say it died in a matter of weeks or months. Some even say they got a Delphi part in a no-name box. There's even a thread here on how to tell:

MPFI spider injector swap/upgrade info and questions thread

I see threads occasionally about this. I just recently did this swap on mine and figured I would post some info I learned with my experience. Also thought this would be a good central location for people to ask questions and troubleshoot all in one inclusive thread. For starts, some info about...

www.gmt400.com

The kicker though, is that Summit sells the delco part for only about $100 more than everyone sells the most popular off brand "Standard Motor Products".

Most of the big online places sell the Standard for $320-340ish. Summit has the ac delco for $444, where many places are selling it for $600+.

Since the Summit price for the delco part is close to the off brand anyway, I'd rather just suck it up and pay then try to play the off brand lottery and hope I get a re boxed Delphi part, and then have to waste even more time and money messing with returns and re-buying, especially since I can't get it though Amazon with prime shipping and easy returns.

I'd rather just do it all at once since this is the origional cpi setup in the truck. If one is dead now I'm sure the others aren't far off. It's a lot cheaper per injector to do the whole spider than it is individual injectors one at a time and 1/8th the work. Plus the mpfi will be better since it was specially designed to work better with the crappy California gas.