Ok so I pulled the VAS and rotated, I can definitely hear injectors clicking and what sounds like the fuel pump cycling when I turn the CAS. now hopefully I get the VAS back in right

yes. You may need to retime the cas. Are there any bolt washer dents in the cas? try to line it up as close to original as possible.

Car should still start with egr unplugged.

thanks for the bolt washer indent tip. unplugged the pass egr solenoid and nothing changed. Still sounds like it trying to start.
I've been fighting this thing since mid spring when my son was up at school and the idle issues and stumbling and stalling started. He is now back at school and I'm still fighting. At the point of frustration where I'm not always thinking clearly.

I noticed my son left the tank on slap empty, God bless him. I had put a gallon in earlier and I thought that was why all of a sudden it seemed like it wanted to start. Just put another 5 gallons in it and same thing. Engine now chugs around sounding like it wants to start. The tach now actually moves a bit when cranking. Stull no start. Done for the day, got other things to attend to

Ok I'm able to work on the car again since Hurricane Ida is gone. I still don't have power yet.

The car has now sat for about a week. I tried to start it this morning and it actually fired up for about a second or less. Then died. Tried to start again and same as last week. Sounds like it is trying to start and engine moves around in mounts but no dice. Will be testing PTU next.

So it now starts for maybe a second then dies. When it does fire it sounds rough. Trying to test the PTU but no matter which pin combination I try I get no resistance reading. Does the PTU need to be bolted in the car to test?

Nolimit has nice instructions here:

dead-cylinder-can-t-figure-out-why-read ... 64452.html

not sure what I was doing wrong but now getting readings. will post later when I can't put it in a chart

http://imgur.com/gallery/qzbasdY


these are the PTU test results. Hope it makes sense

So car will start but feels and sounds like not running on all cylinders. Will rev a lil but won't idle. Instantly dies if I don't feather the gas. That being said, the PTU is hooked up but not bolted down. Not sure it THAT is my issue.

I OHMd the injectors and all are eight around 12ohm. I also OHMd the coils and I get 0.0 ohm for all 6 coil packs.

So car idles, barely, around 250 rpm or so. Started pulling coil plugs. when I pull #2 OR #6 the engine dies. If I pull ANY of the other 4 coil plugs NOTHING happens. Could I really have 4 dead cylinders? Car ran b4 pulling manifold to change injectors. could it be the injectors? Screwed up and bought injectors from Amazon BEFORE I found out how picky these cars are.
When I pull CAS and rotate by hand I can hear each injector make noise. When I check for resistance all 6 injectors check out. When I check resistance for each coil they also check out as well as voltage at each coil.
I checked resistance on the PTU and posted link above with results. Can anyone verify is PTU results are good or not? Running out of luck

Latest update

Last night I fired up the car and ran like he'll. Started pulling coil plugs to isolate coils. results below

Pulled #2 car died
Pulled #4 nothing happened
Pulled #6 car died
Pulled #1 nothing happened
Pulled #3 nothing happened
Pulled #5 nothing happened
Started car, still runs like crap and barely idles, maybe 250rpm. I decided to swap the #2 and # 4 coils to see what happens. Restarted car and Pulled #2 connector which now has #4 coil and car died. Then restarted car and Pulled the #4 connector which has the #2 coil installed and nothing happened.. This tell me that the coils aren't bad since regardless of coil installed pulling the #2 coil plug kills the car and pulling the #4 connector does nothing.
Oddly the #2and #6 spark plugs, the only 2 cylinders firing, are really black. The other 4 plugs, cylinders NOT firing, all look normal.
I am starting to believe the Amazon injectors I bought are crap.

Any thoughts?

Went to my local dealer to check on injectors. $185 each. He showed me the diagram he has and it isn't a good diagram. It does kind if look like my car came with phase 1.5 injectors. Again, crappy diagram. He looked it up with my VIN. How can a '96 have phase 1.5 injectors?

Are you sure you bought NA injectors

Are the plugs on the dead cylinders clean and moist or are they dry

Black plugs means running rich

Have you done the screwdriver listening test on the injectors while the car is running

Don't buy injectors from the dealer, they are overpriced. Order them from concept Z performance or Z1 they are about $600 for a set.

Or try finding some used ones online I'm lying for instance on eBay on eBay just to test

Yeah, I got NA injectors. I bought a set of phase 2 injectors from Amazon. Mistake. My car for some reason has phase 1.5 injectors. I haven't done screw driver check but cars barely runs. if I disconnect coil 2 OR 6 while running the cars dies. I'm thinking it is only running on 2 cylinders.
As far as injectors, Rock Auto has new Hitachi injectors for like $60 each. Is it worth it to get them from there.

I have no experience with Hitachi injectors but I would err on the side of caution and pay the price for OEMs.

Logic would dictate that the issue is either the injectors or the installation (badly seated injectors, bad seal at the upper plenum, vacuum leak. basically anything that was disturbed during the injector swap. You need to retrace your steps and stop concentrating on the injectors/PTU. Maybe get a smoke test to start or try spraying starter fluid (short blasts) at the locations where a vacuum leak may exist. I'm suggesting starter fluid because it sounds like the car may die on its own so not a good identifier to use card cleaner. Starter fluid will make it kick the revs up, easier to pinpoint in the current condition. If the old injectors aren't completely destroyed or if at least a couple aren't then try replacing the new ones with the old ones and see if it makes a difference.

You didn't answer if the plugs on the dead cylinders are wet or not. You may have some pinched o-rings which is causing immense amounts of fuel into your cylinders. If you didn't use some type of lube to set the injectors in the fuel rail I would put money on that being the issue.

the plugs on the dead cylinders are dry and look normal for their mileage and don't smell like gas. The 2 plugs from the running cylinders are black and sooty.
The injectors that came out of the engine are phase 1.5s and the ones I bought are phase 2. Most of the 1.5s got damaged during removal due to them being very stuck.

ok, lube on the new ones?

yes, lube on new ones. All the injectors went in fairly easily. Slight wiggle and a lil pressure and they went in. No fuel leaks anywhere. The plugs for all 4 dead cylinders look and smell the same, like they are getting zero fuel. I can see if they looked or smell differently but they aren't.

You might have a connector-pin issue, sometimes aftermarket male pins are skinnier than they should be and it causes problems with the original female pins. We see it very frequently with A/C compressor connections. Using a bulb-type test light, try back-probing the ECM side of one of the injectors that are running dry. The light should be dim with the key on and blink out when the injector fires. If there's no light then one or both of the connector pins isn't making contact.

I'll try that but when I removed the CAS and spun by hand all the injectors made noise

Opening the plunger against fuel pressure and opening it with a dead rail are different things. It probably wouldn't take more than 4~5 ohms of added resistance to cause a problem. A bulb-type light will show a marked difference in brightness from 4~5 ohms.

PS - You can also check voltage at the test lamp, it will basically give you a "fixed load" to check against. They should all read about the same voltage through the lamp if the connections are healthy.

what test lamp? I am getting 12 volts at all the injector connectors

I suspect the injectors are not opening even though you hear the click while rotating the CAS

I'm not sure if you want to try this; but might save you the hassle of ripping the plenum off again.

I previously made a pressure test setup for the fuel lines on the engine.
Basically disconnect the two fuel hoses on the driver side and let dry for a bit.
Make a fitting for the inlet side (fuel filter side ) and apply a small bit of air <20psi and confirm air out the outlet line.
Plug out line and apply 30-40 psi air. Holds pressure? good
Carefully apply 12V to each suspect injector and see if air pressure drop. Pressure drop? yes injectors work as they should.

This will confirm your Amazon injectors are at least operating. Then lets rule that out and go from there.

Any bulb-type test light. This is the one I use from Harbor Freight:

https://www.harborfreight.com/612v-circ ... 63603.html

It's important to use a bulb and not an LED because a bulb loads the circuit. When checking power circuits, you use something that draws power. That tells you the circuit can carry a load, which a meter or LED won't. To check the injector connections, you'll back-probe the injector trigger wire with a t-pin or safety pin and connect the pointy end of the test lamp to it. The clamp end of the test light will go to ground. You should get a dim bulb with the key on (dim because the current is flowing through the injector first and then the lamp). With the circuit loaded, you can then put a voltmeter between the pointy end and ground, all the injectors should read about the same voltage. Any injectors that either don't light the light or read substantially lower voltage than the others have poor connections.

Not sure how up you are on my issues but my son was having running issues. Normally ran fine then it would act up. No real pattern or repeatability. This went on for 2-3 months. During that time I changed the fuel pump, then the pump controller with a used one from Z1. Nothing changed with either. Ordered Z1s pressure test tool for the intake tract and fixed several air leaks, nothing changed. Tested the TPS and it was normal. Checked al electrical connectors and they were all tight, clean, and no corrosion. The reason we pulled the manifold was to change injectors as we were running out of options. Even when son was having problems, when it wasn't acting up, car ran good and strong. It would pull hard to redline in the 1st 3 gears no problem. I pulled the IACV to check it. Took it apart and cleaned it. To be honest it wasn't bad at all. Coils get 12 volts as well as OHM out properly. Even the PTU seems to check out.
I messed up and ordered cheap inje toys from Amazon before finding out not to. This is what is leading me to believe I got screwed and got crap injectors. The Amazon ad didn't mention used or rebuilt but I'm betting they were 1 of those 2. I'm out less than $50 because of it. I'm waiting son's school money to come in to order injectors. This is his car so he said he would pay for them.

scottgas wrote: ↑

Mon Sep 13, 2021 2:52 pm

Not sure how up you are on my issues but my son was having running issues.

I've been following your travails, but in general, NoLimit and itsa300 are way better with oldie Z stuff than I am. I just chimed in because electrical is my bailey and it wouldn't be the first time I saw cheap connector pins cause intractable problems. Besides intermittent short circuits, they're probably the toughest electrical issue to identify and diagnose. Getting a test light to find out is way better than hair-pulling, I'm certain of that.

I appreciate ALLLLLLL help. Ive been working on crap for 35 years and electrical is my 1 big week link. My head is shaved otherwise I would have pulled out anything left.

Except for the stumbling stalling crappy idle issue, that seems to be common, that we were having the car ran great.

One thing I noticed before was the smell of gas at times after the car was driven. I never saw any leaks anywhere though.

Also, I think we have an electrical drain issue with the car too. I'm sure that won't be fun to chase.

CAR RUNS AGAIN!!!!!

So I ordered new injectors from Concept Z Performance. They actually have phase 2 Jecs brand injectors on sale for $70/each. I also ordered their Allen head screw set to replace the nearly stripped factory phillips screws.

I DID NOT pull the manifold again. I saw a video showing how to grind away parts of the manifold to be able to get the screws out. Worked like a charm.

It took a couple turns of the key to finally start but once it did it settled into a nice stable idle. Took the car out and put about 15 miles on it of both heavy throttle high rpm runs then some slow driving through the neighborhood. So far so good.

Hopefully this is it for the car. Fingers crossed.