Integra Type aRgh- a LoPrep Challenge build

In reply to Slippery :

How hard should one swing? 
I was knocking on it a bit to see if it helped but no change 

Depending on the injector type, they aren't that difficult to disassemble and clean.

I was thinking it was an injector since page one, but admittedly I was guessing.  You can probably test the coils to see what the resistance is across all four.  If the #1 injector shows a different resistance, bingo.

I can sometimes get them to free up by slamming them down on a wood countertop with the palm of my hand.  If it hurts your hand, it's too hard.

New or reman injectors should be $25.  Probably $10 from a boneyard.

The other test that's pretty easy to do is to charge the rail, then activate one known-good injector, like #4.  Watch the pressure drop.  Recharge the rail and do the rest the same way.  My guess is that the #1 injector either doesn't let the pressure drop, or it drops much slower.

Got the injectors pulled. 

Tim has volunteered to attempt a resurrection this weekend. 
Fingers crossed 

Cooper_Tired said:

Got the injectors pulled. 

 

Tim has volunteered to attempt a resurrection this weekend. 
Fingers crossed 

I like how this picture makes the rumpke url look like a watermark.

In reply to eastsideTim :

The injectors look like they came from Rumpke

Definitely recover the seals from injectors #1 and #2 as they appear to have not come off with the injector itself. 

In reply to Cooper_Tired :

Put 12v through them with a jumper and listen to see if they click. 

Fwiw, I went down a lot of the same diagnostic rabbit holes before finding a plugged injector in Nicole's AW11. Weird stuff happens when cars sit. 

Curtis73 (Forum Supporter) said:

The other test that's pretty easy to do is to charge the rail, then activate one known-good injector, like #4.  Watch the pressure drop.  Recharge the rail and do the rest the same way.  My guess is that the #1 injector either doesn't let the pressure drop, or it drops much slower.

Agree. This is what I did when I was going through this problem that turned out to be a stuck injector. The stuck injector was after changing the headgasket, it sat for a couple of months max. 

I had a way to activate each injector, but you can just power them with 12v for the same results. 

Picked up the injectors from Cooper_Tired last night, and today, during a break from garage cleaning, I tested resistance on them.  All were between 11.8-12.0 Ohms, so I am assuming none of them are bad.  I threw together a cleaning rig based on some youtube videos I'd watched.  Being a hoarder, I had all the necessary parts lying around.  For each one, I removed the filter and o ring, and soaked the filter in some throttle body cleaner.  Then I spayed more throttle body cleaner through the injector while rapidly cycling it.  #1 was the worst, but it cleared up almost instantly.  #2 or #4 seemed a little bit bad, too, but not as bad.  Now, they are spraying pretty well, so I just need to get them back and see if they help the Integra run better.

In reply to eastsideTim :

Thanks for getting them flushed out! 
Looking forward to trying them out 

There are all kinds of things that can go wrong with injectors (although they're usually pretty bulletproof)

The pintle can break, meaning that the solenoid works fine but it doesn't pull the needle out of the hole.  The solenoid might click but not move.  The nozzle can be plugged.  It might click and flow, but could be weak and not flow enough.

Glad they're clean and ready to rock.  (he says hopefully)

Fingers crossed!

In reply to Curtis73 (Forum Supporter) :

Agree

worst case rebuilt replacements are ~$60/set on eBay or $23ea on Rock auto

In reply to Cooper_Tired :

If you end up getting replacements and are considering going boost, get CNG (natural gas) civic injectors as the replacements 

In reply to Captdownshift (Forum Supporter) :

Oh thanks for the tip! Boost is definitely in the post-challenge plans 

In reply to Cooper_Tired :

Hold off on the CNG ones until you have engine management then, but it's a tip for the future. 

Finally an update. 
 

Tim and I had a few mins to mess with the Argh today.

we popped in the freshly cleaned injectors and fired it up. It purred like a kitten. Smooth idle no shaking. Cracked the throttle and still smooth.

For less than a minute. Hopped in to drive and the shaking and misfire started back up. 
Pulled plug wires to chase the suspect cylinder and it was # 1 again. 
Checked primary temp again and confirmed cyl 1 much cooler.

Dug into cyl troubleshooting again. 
Swapped the injector from cyl 1 with cyl 2. 
Did the plug wire check and the temperature check. Issue stayed at cylinder 1. So it's not the physical injector. 
Confirmed spark at cyl 1- it's there. Pulled plug on cyl 1- looks dry and no fuel smell

plug on cyl 2 - fuel smell; evidence of combustion. 
 

Had to stop for the night but made some progress; 

problem seems to be fuel related

problem did not follow the injector. 
 

wondering if we have an issue in the wire or if it's possible the issue lies in the ECU

on a positive note, ordered a full eBay cat back to replace the rotten one this morning. I'm hoping $130 of Chinese stainless steel doesn't sound too awful running on 3 cylinders 

I would check the resistance, one lead at the injector plug and the other at the ecu. 

I don't know exactly what ecu that car has, but did a quick search for a '94 pinout and found this. Might not be the right one, but gives you an idea of what to look for. 

There should be a pin for eqch of the injectors, and they should go all the way to the plug. 

BTW, I would still pop the valve cover and make sure everything is alright in there. 

Slippery said:

I would check the resistance, one lead at the injector plug and the other at the ecu. 

Yup, that is part of the plan.  My guess is the Cooper_Tired moving the injector rail around made the connection better, and the car/engine moving broke the connection.  If we can find pin outs for the engine compartment plugs, I think we can test from there, instead of having to crawl into the passenger seat floor and disconnect the ECU.  Before that, just in case, I'll see if I can run over there with my noid light set.

Small update:

Dave came over today with Tim's noid set to check the injectors. 
 

Prior to his arrival I did a few checks.

Checked resistance on injector 1 and 2. Both identical at 11.8 ohms. 
Checked voltage at the connector on 1 and 2, both 11.9 Volts

Fired up the car and it idled great, revved smooth for the first minute the misfire came back. 
Connected the noid and both 1 and 2 appear to be pulsing as expected. 
Didn't pull the injector to inspect flow but as the issue stayed the same across 2 injectors I'm going on the assumption the issue isn't a mechanical issue on the injector. 

Had to stop for the night, but so far it appears the issue is gone for the first few seconds on cold starts, still persists at the same cylinder, the injector is getting pulse, the ignition is firing.

Next step we are going to dig into the valves. 

I'd pull #1 injector out of the rail and run the fuel pump for a bit. Could be a chunk of something in the rail between 1 and 2 that falls away when pressure drops overnight, then gets pushed back into place after a couple seconds of running.