Hard to start after fuel injector replacement and other running issues

Have a flashing light? Gauges acting funny? Bad idle? Get your problems solved...
Cam2363
Registered User
Posts: 261
Joined: Sun May 20, 2018 5:35 pm
Has thanked: 3 times
Been thanked: 1 time

Hard to start after fuel injector replacement and other running issues

Postby Cam2363 » Sat Aug 31, 2019 7:58 pm

This is a new post continuing off my last one, but Im adding other issues im having to, I assume are connected with this somehow.

(96 z26 3.1L

I replaced my injectors and O2 sensor today in the quest of better MPG, and after, the first start was rough, but I expected this, what I didnt expect is the start about 4 hours later to struggle. Before this, you would turn the key for under a second and it would fire right up, but now it cranks longer and kind of sputters to life, like it doesnt fire up smoothly, so I drove it, got it warmed up, and it did the same thing warm, took a while to crank, didnt go instantly as it used to, try again for a little longer, sputters to life. But once it is running, it runs fine.

Does anybody have any ideas on what to check? I have no lights indicating anything.


UPDATE:
I did a fuel pressure test, it goes up to around 41 or 42 psi, which according to my manual is normal, but after a few minutes drops down to the low 20s. I starter the engine and it goes down to around 37 which according to the manual is also normal (3-10 psi drop when running). I also checked around the injectors and around the inlet and outlet pipes and there is no fuel around them. So my guess is that some injector is leaking into the engine. Anybody know how to figure this out without taking everything apart? I check the front plugs and they look fine, the back ones are too much of a pain to remove tho lol.

And I have checked the connections on the tester. There is no fuel leaking, nor can I hear any air leaking out of them.

And I used my remote start to start it cold the other day, and it took probably around 4 to 5 seconds before it started and ran.

https://imgur.com/a/1c8HYnc

Thats a link to a video I took of it starting using my remote start)


That is the problem Ive been having. Due to suggestions, I took plugs out. Every single one looked fine (see pic) and there was NO gas smell on any of them. What I did notice was a gas smell near the rear of the engine closer to the PS pump
20190831_154302.jpg


Another issue ive been having for a while and I finally figured out what the cause of it is, is the bucking shortly after starting sometimes. (See videos)

I found this issue to be something with the brakes. If I start it cold and pump the brake pedal, the engine starts doing it. I also got it to do it without messing with the brakes, and just playing with the throttle.

https://imgur.com/a/Ryza1oi There are the links of the bucking.

Any help or tips would be appreciated! I thank you all for trying to help me haha



User avatar
heavywoody
Global Moderator
Posts: 1960
Joined: Sun Nov 03, 2002 4:10 pm
Location: Concord, NC
Has thanked: 8 times
Been thanked: 21 times
Contact:

Re: Hard to start after fuel injector replacement and other running issues

Postby heavywoody » Wed Sep 04, 2019 8:30 am

If you have a gas smell near the PS pump, my first place to check would be the schrader valve on the end of the fuel rail. Could be leaking past the o-ring.

Also, when the car is running, take the vacuum line off the fuel pressure regulator. It will stumble but shouldn't stall out - if there is gas coming out of the port in the top of the pressure regulator, the diaphragm inside is broken, so the regulator would need to be replaced.

Have you tried spraying intake cleaner/starting fluid around the vacuum line that runs to the brake booster from the intake manifold? Sounds like a vacuum issue on the bucking.


Geoff
95 Z26 Turbo 3400 5spd - R&D Project
Beretta Preservation Society - Director of Acquisitions
Image

Cam2363
Registered User
Posts: 261
Joined: Sun May 20, 2018 5:35 pm
Has thanked: 3 times
Been thanked: 1 time

Re: Hard to start after fuel injector replacement and other running issues

Postby Cam2363 » Wed Sep 04, 2019 3:48 pm

heavywoody wrote:If you have a gas smell near the PS pump, my first place to check would be the schrader valve on the end of the fuel rail. Could be leaking past the o-ring.

Also, when the car is running, take the vacuum line off the fuel pressure regulator. It will stumble but shouldn't stall out - if there is gas coming out of the port in the top of the pressure regulator, the diaphragm inside is broken, so the regulator would need to be replaced.

Have you tried spraying intake cleaner/starting fluid around the vacuum line that runs to the brake booster from the intake manifold? Sounds like a vacuum issue on the bucking.


How would I be able to tell if the O Ring is leaking. This might actually explain a lot because I might have damaged it when releasing pressure. I will try the strarting fluid trick then and also the FPR



Cam2363
Registered User
Posts: 261
Joined: Sun May 20, 2018 5:35 pm
Has thanked: 3 times
Been thanked: 1 time

Re: RE: Re: Hard to start after fuel injector replacement and other running issues

Postby Cam2363 » Wed Sep 04, 2019 4:07 pm

heavywoody wrote:If you have a gas smell near the PS pump, my first place to check would be the schrader valve on the end of the fuel rail. Could be leaking past the o-ring.

Also, when the car is running, take the vacuum line off the fuel pressure regulator. It will stumble but shouldn't stall out - if there is gas coming out of the port in the top of the pressure regulator, the diaphragm inside is broken, so the regulator would need to be replaced.

Have you tried spraying intake cleaner/starting fluid around the vacuum line that runs to the brake booster from the intake manifold? Sounds like a vacuum issue on the bucking.


Ok. So I did those checks. Fuel smell most definetly coming from the Schrader valve. Most likely my issue. Thanks!!

Fpr was fine. No gas leaking, and the engine didnt even stumble. I tried with my finger on and off the regulator.

Also, I tried the vaccum trick and nothing. I actually really havent had this problem since I took my plugs out, which involved me taking off the brake vaccum hose, and maybe i put it back on a different way allowing it to seal? Just a guess but it hasnt happened since then so that seems fixed


Sent from my SM-G975U using Tapatalk



Cam2363
Registered User
Posts: 261
Joined: Sun May 20, 2018 5:35 pm
Has thanked: 3 times
Been thanked: 1 time

Re: Hard to start after fuel injector replacement and other running issues

Postby Cam2363 » Fri Sep 06, 2019 8:30 am

Heavywoody, THANK YOU! I replaced the valve yesterday with one from another fuel rail that I had. And its started up pretty much normally since then. I did notice the little stem was bent slightly, so that might have been the issue.

I'll keep an update on how it goes then

Sent from my SM-G975U using Tapatalk



Cam2363
Registered User
Posts: 261
Joined: Sun May 20, 2018 5:35 pm
Has thanked: 3 times
Been thanked: 1 time

Re: Hard to start after fuel injector replacement and other running issues

Postby Cam2363 » Sat Sep 07, 2019 3:39 pm

Spoke too soon, still had trouble. But I dont think its fuel-related now. I was driving home from work and my service light came on and then it started doing the bucking. Sure enough, it was a misfire code. I managed to limp it home, but there is definitely a problem with the coils and not the injectors. So at least thats solved! I hope replacing them with another set I have will help fix this annoying issue.



User avatar
heavywoody
Global Moderator
Posts: 1960
Joined: Sun Nov 03, 2002 4:10 pm
Location: Concord, NC
Has thanked: 8 times
Been thanked: 21 times
Contact:

Re: Hard to start after fuel injector replacement and other running issues

Postby heavywoody » Sat Sep 07, 2019 10:29 pm

What code came up?


Geoff
95 Z26 Turbo 3400 5spd - R&D Project
Beretta Preservation Society - Director of Acquisitions
Image

Cam2363
Registered User
Posts: 261
Joined: Sun May 20, 2018 5:35 pm
Has thanked: 3 times
Been thanked: 1 time

Re: Hard to start after fuel injector replacement and other running issues

Postby Cam2363 » Sat Sep 07, 2019 11:16 pm

P0300

But its worse than that. I got back from work, went to start it and it would crank like for a second and then would stop and the starter would buzz. It was locked up. I found out that cylinder 5 had a lot of fuel in it, and I thought that because the coil for 5 was damaged a bit, it was missing, filled with fuel and was the issue. So I cleaned it out, put it back together and now it won't start. It fires up for a second and then dies. The fuel pump is also louder than it used to be. I did add a bit more fuel, but Ive had the needle on the gauge lower and still had a gallon left. So im not really sure what's going on at this point. I'm going to try starter fluid in the intake tomorrow and see where that gets me.



User avatar
Rettax3
Registered User
Posts: 1508
Joined: Mon Oct 22, 2012 3:34 pm
Been thanked: 6 times

Re: Hard to start after fuel injector replacement and other running issues

Postby Rettax3 » Sun Sep 08, 2019 1:30 am

P0300 is 'random misfire', meaning either that the misfire really is jumping all over (not going to be caused by a single bad coil, maybe a failing ICM or CKPS though), or the PCM has NO CLUE which hole the misfire is coming from. A major injector failure is just about as likely to cause a P0300 as a coil issue -the computer reads an improper fuel mixture caused by one cylinder and over-reacts by trimming fuel too far on ALL cylinders, which certainly can cause multiple-cylinder misfires. GM's coding is not bad on this, I could share some fun stories about the horrendously mal-adaptive programming that VW's have, where a relatively minor vacuum leak in the PCV system can cause dramatic fuel-trims and wild ignition timing fluctuations exceeding 40 degrees, even firing 20-30 degrees ATDC, so severe that it will backfire into the intake and eventually damage the engine, but really, GM isn't THAT bad, not in this era at least. It looks like your new #5 injector, maybe others too, is leaking badly enough to screw everything else up. Hoping at this point that hydro-locking the engine didn't break something mechanical, like a connecting-rod, for instance...


1989 SuperCharged 3800 Srs-II (First)Six-Speed GTU
1990 Turbo 3.4 5-Speed T-Type
1990 4.0L 4-Cam 32-Valve V-8 5-Speed Indy GTi (Project)
1990 Stock(!) 3.1 MPFI Auto Indy
1995 LA1/L82 4T60E Z-26
1995 3.4 DOHC Turbo 5-Speed Z-26

Cam2363
Registered User
Posts: 261
Joined: Sun May 20, 2018 5:35 pm
Has thanked: 3 times
Been thanked: 1 time

Re: RE: Re: Hard to start after fuel injector replacement and other running issues

Postby Cam2363 » Sun Sep 08, 2019 1:39 am

Rettax3 wrote:P0300 is 'random misfire', meaning either that the misfire really is jumping all over (not going to be caused by a single bad coil, maybe a failing ICM or CKPS though), or the PCM has NO CLUE which hole the misfire is coming from. A major injector failure is just about as likely to cause a P0300 as a coil issue -the computer reads an improper fuel mixture caused by one cylinder and over-reacts by trimming fuel too far on ALL cylinders, which certainly can cause multiple-cylinder misfires. GM's coding is not bad on this, I could share some fun stories about the horrendously mal-adaptive programming that VW's have, where a relatively minor vacuum leak in the PCV system can cause dramatic fuel-trims and wild ignition timing fluctuations exceeding 40 degrees, even firing 20-30 degrees ATDC, so severe that it will backfire into the intake and eventually damage the engine, but really, GM isn't THAT bad, not in this era at least. It looks like your new #5 injector, maybe others too, is leaking badly enough to screw everything else up. Hoping at this point that hydro-locking the engine didn't break something mechanical, like a connecting-rod, for instance...
Hope so too. Plan is to clean the old injectors and then put then back in after putting new Oring on. Do you have any suggestions on cleaning them?

And I hope not. The car would start and run, but only for a second and then die. So my guess is theres a fuel or ignition issue. I'm going to replace my injectors and see what the guy I got them from can do for me. Hopefully I can just return them, but I doubt it because they were already used

Sent from my SM-G975U using Tapatalk



Cam2363
Registered User
Posts: 261
Joined: Sun May 20, 2018 5:35 pm
Has thanked: 3 times
Been thanked: 1 time

Re: Hard to start after fuel injector replacement and other running issues

Postby Cam2363 » Sun Sep 08, 2019 3:10 pm

Went out again today, tried to crank. Cranked a few times and then made a sound like it got stuck and then would do it again. There is definitely a fuel smell and some other smell that is unfamiliar to me


Sent from my SM-G975U using Tapatalk



Cam2363
Registered User
Posts: 261
Joined: Sun May 20, 2018 5:35 pm
Has thanked: 3 times
Been thanked: 1 time

Re: Hard to start after fuel injector replacement and other running issues

Postby Cam2363 » Sun Sep 08, 2019 9:43 pm

Fighter out the issue. When I took injector 5 out, I hooked it up to my test apparatus, and before putting any pressure or power, it was leaking everything right out. So that's my issue right there.

As for the smell by the PS pump, I also saw that I had put the clip for holding in injector 1 on the tube that connects both halves. How I did that? I couldn't tell you, but I think that was my issue. And number 5 was probably leaking a bit making it hard to start, and then it just got stuck open and was pouring fuel in. When i released the rail pressure, there was none, and there was no fuel that came out of the lines when I removed them, so it was just all leaking in my engine lol

Sent from my SM-G975U using Tapatalk



User avatar
ifixalot
Registered User
Posts: 613
Joined: Tue Dec 26, 2006 10:56 am
Location: Deerfield Illinois
Been thanked: 15 times

Re: Hard to start after fuel injector replacement and other running issues

Postby ifixalot » Mon Sep 09, 2019 10:52 am

Gosh, you are having so much trouble with that car. I hope you get it sorted out. But you are learning stuff that may be useful
your whole life.
As far as cleaning injectors. They don't come apart. I think the only way to clean them is a machine which would pump some chemicals through to remove deposits. I took some early injectors apart and they were clean inside so I doubt they really need cleaning. It would have been best to read your spark plugs before changing the injectors to see if you had a bad one. At this point, I'd check the coil resistance to make sure they are about 11 ohms with none being way off. If OK, I'd out em back in and maybe run double strength of injector cleaner if you think they need cleaning. Good luck.



Cam2363
Registered User
Posts: 261
Joined: Sun May 20, 2018 5:35 pm
Has thanked: 3 times
Been thanked: 1 time

Re: RE: Re: Hard to start after fuel injector replacement and other running issues

Postby Cam2363 » Mon Sep 09, 2019 12:39 pm

ifixalot wrote:Gosh, you are having so much trouble with that car. I hope you get it sorted out. But you are learning stuff that may be useful
your whole life.
As far as cleaning injectors. They don't come apart. I think the only way to clean them is a machine which would pump some chemicals through to remove deposits. I took some early injectors apart and they were clean inside so I doubt they really need cleaning. It would have been best to read your spark plugs before changing the injectors to see if you had a bad one. At this point, I'd check the coil resistance to make sure they are about 11 ohms with none being way off. If OK, I'd out em back in and maybe run double strength of injector cleaner if you think they need cleaning. Good luck.
Thanks. For the cleaning I was using some carb cleaner in a syringe which I used to pressurize it and then pulse the injector to run it through.

Turns out tho only one needs replacing so like I'm gonna replace that one and see where it gets me. I also did my plugs only 6 months ago and have had no problems since the injector install. I will definetly test the coils though. I planned to do it anyway, just kept forgetting haha.

I also replaced my 2/5 coil because it had a crack in the 5 post, which I thought was part of the cause of the missing, but it wasnt, but atleast it's fixed now.

Sent from my SM-G975U using Tapatalk



User avatar
Rettax3
Registered User
Posts: 1508
Joined: Mon Oct 22, 2012 3:34 pm
Been thanked: 6 times

Re: Hard to start after fuel injector replacement and other running issues

Postby Rettax3 » Thu Sep 12, 2019 3:23 am

I have found an injector 'cleaner' kit/tool that uses the carb cleaner aerosol can and a 12V source to fire the injector, thereby 'cleaning' it, they are cheap but not sure how well they really work, and you need to be CAREFUL with that kind of thing -you are pushing that injector to 100% duty cycle, they can fry if pushed much past 80% for long at all. Soaking might be better... And the filter-screens on the inlet side are replaceable. That is about all you can really service on those things.


1989 SuperCharged 3800 Srs-II (First)Six-Speed GTU
1990 Turbo 3.4 5-Speed T-Type
1990 4.0L 4-Cam 32-Valve V-8 5-Speed Indy GTi (Project)
1990 Stock(!) 3.1 MPFI Auto Indy
1995 LA1/L82 4T60E Z-26
1995 3.4 DOHC Turbo 5-Speed Z-26


Return to “Diagnostic Help”

Who is online

Users browsing this forum: No registered users and 1 guest