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Author Topic: Engine hesitation  (Read 473 times)

Offline deucekazoo

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Engine hesitation
« on: 12:40:24 PM / 30-Aug-16 »
Just want to see if anyone has had this same situation. But before I ask the question here is a little on the car. Its the CA18ET engine and the turbo does not work. I have a new one waiting to put on but have not had the time. So the original turbo is seized up and does not move at all. I think that might be causing my issue but not sure.

So the car runs good for the first 15 to 20 minutes. After that I have power loss at 2K and then at 3K rpms. So trying to take off it hits 2K and then just bogs down, hardly any power and starts to sputter. Once I get past that it is fine until it hits 3K and does the same thing. Just major loss of power. Before this the car runs find and pulls hard, well ask hard as it can on 70 horse power (no turbo). But it runs fine and no hesitation. But once it has been running for a certain time it starts the loss of power. I am thinking it might be the turbo in line, once it gets hot is swells and stops or restricts the flow. But why would it only be at 2K and 3K rpms?
What do you guys think, what else should I look at. The car has new plugs, new vacuum lines and new fuel filter. The cap and rotor looked new but not sure about the wires. I do want to get new ones.
So has anyone had this issue or close to this issue? Let me know what you guys think might be causing this.
Thanks,
John

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Online kelso840

Re: Engine hesitation
« Reply #1 on: 01:11:27 PM / 30-Aug-16 »
Sounds a lot like the power loss I was experiencing right around 3k rpm that got cleared up with two new ignition coils (~$30 for both).

One thing you can try without spending any money is disconnecting one coil at a time while the car is running and seeing if there's any change. Your car should be able to run at idle on either the ignition or exhaust coil alone. That magic 3k point is where (I believe) the spark stops being delivered to the exhaust bank, so if your ignition coil can't handle the load at idle, no way it's up to the task at increased RPMs.

If you pull the plug wire off of one coil and the car dies or starts to stumble/sputter, that means the coil that is still connected is weak and not sending a strong enough spark through the wires.

As always, I could be very wrong. Good luck.
Infrequently driving an s12.

Offline deucekazoo

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Re: Engine hesitation
« Reply #2 on: 01:55:19 PM / 30-Aug-16 »
Sweet I will give that a try and see what happens. Thanks.
Post Merge
So last night I tried running each coil separately. No change, the car idled good either way. But I do have future plans to replace the coils with some MSD coils and wires.
« Last Edit: 07:52:49 AM / 31-Aug-16 by deucekazoo »

Offline deucekazoo

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Re: Engine hesitation
« Reply #3 on: 09:33:16 AM / 09-Sep-16 »
Well last night it broke down on me on the way home from work. It did the slight hesitation again but then started to sputter. Kind of sounded like a diesel so I though I broke the timing belt or jumped a tooth. I took the cover off on the side of the road and the belt is in one piece. Does not look pretty (its old and cracked) but is in one piece. Over the weekend I installed a fuel pressure gauge so it shows 32+ psi when cranking so fuel pump should be good. So I am thinking it could be spark or a sensor or the computer. I hope it's not the computer.

So any ideas guys, it cranks fine, has fuel pressure and timing belt is in one piece.

Thanks,
John

Online kelso840

Re: Engine hesitation
« Reply #4 on: 12:34:49 PM / 09-Sep-16 »
I would pull the distributor, set the motor to TDC by hand, then re-install distributor and give it a go. Also make sure your throttle position sensor/switch on the back of your intake isn't loose, busted up, or has a wire fraying. If nothing at all works I'd seriously consider buying one new coil and swapping out the primary. They're pretty cheap for a potential magic bullet.

Mystery quits are the worst part of CA ownership. Far too frequent and I never know exactly what fixes stuff.
Infrequently driving an s12.

Offline Redneck

Re: Engine hesitation
« Reply #5 on: 10:17:23 PM / 09-Sep-16 »
Considering your turbo is frozen further diagnosis seems somewhat irrelevant. That is a huge x factor. Personally tho I think 30 year old ca18et's are just one huge x factor. You spend time and money fixing one thing only for some other random problem to often pop up a couple weeks later. I did this for years until I finally ditched the ca18 for the ka24, problem solved. In the long run swapping to a more reliable engine is a much more realistic solution if you plan to daily it. If your looking for a stock s12 to daily the ca20 and vg30 seemed to be much more reliable in general compared to the ca18.
FIrst my rims are horrible, than there ok when painted black , now my cars horrible, now my fenders are to much after i was told i couldnt do it.... Lol club s12 ftw.....  Only here have Ive been told they look like shit..... SOrry its not bone stock with crown vic rims running the stock vg making 130whp and looks generic like every other one. My car looks dope ive been told this a billion times on local forums....


Online kelso840

Re: Engine hesitation
« Reply #6 on: 07:03:40 AM / 10-Sep-16 »
Redneck is right but I also understand that swapping isn't a practical or financially viable option for everyone for various reasons. Nickel and diming a CA along can work if your goal is to be driving an s12, you just may not be driving it as often.

I forgot your turbo is done, but if you had it running before you should expect to be able to get to it run at least that well again.
Infrequently driving an s12.

Offline deucekazoo

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Re: Engine hesitation
« Reply #7 on: 09:38:17 AM / 12-Sep-16 »
I know what you guys are saying but I don't want to give up on the CA18 yet. I think they are good motors but just need a little TLC.
My turbo that I picked up a while back is finally done. My buddy finally put it back together. The issue was, I thought it was a basic GT28 turbo, but it turned out to be a GT28R which is a bearing turbo. The rebuild kit was a lot more expensive but its finally back together. Now I just need to put it on the car.

So back to my car dying. It was a simple fix but this never happened to me before with any of my cars.

The bolt that holds the rotor inside the cap vibrated loose and fell out. The rotor is pretty tight on the shaft so it still worked and then did not work. So my hesitation issue I think was that. It was retarding timing or out of timing when it was slipping. I don't know when the bolt fell out. When it died I wonder if the bolt just wedged itself between the rotor and cap and stopped it from moving or that is when it fell out.
The rotor looked new so I think the previous owner replaced the rotor and cap and might not have tightened the bolt down enough. So I put a little blue thread lock on it so this does not happen again.
All is well now and car runs good again.

Offline rednucleus

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Re: Engine hesitation
« Reply #8 on: 10:40:04 AM / 12-Sep-16 »
Good find - not the 1st time I have heard this story with our cars

Offline deucekazoo

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Re: Engine hesitation
« Reply #9 on: 08:56:34 AM / 08-May-17 »
Well my issue is back!!!

Now I am really thinking it is wiring related. So the last thing I put on the car is a wide band O2. I put the gauge inside and run a narrow band signal into the car ECM. This is a PLX unit and I like it. So once I installed it, the issue slowly came back. I was moving and pushing wires out of the way to install the wires for the new gauge to make it look nice. But now I see what the car is doing when it looses power an starts to hesitate. It is running lean. Too lean, all the way in the red at 18+ on the gauge. But if I give it more gas and a few seconds it gets out of it and pulls like crazy and the gauge drops to 10.8-12.5 where it is supposed to be, and then back to hesitating. I was thinking it could be the fuel pump going out but I need to get a pressure gauge on the inside to see the pressure when this lean condition happens. But the car runs OK when it is cool/in the morning and only does this lean condition when it gets warm or sits in the hot sun. The only other reason I thing it is the wiring is I just put a new speed sensor on the car because the old one did not work. This new one worked perfect for a week and then when this lean condition happened again the gauge now shows 0 or shows me going 19 when I am doing 65 on the highway. So my plan of attach is to find all the main connections and clean them. I hope this fixes the problem.
But anyway did anyone run into this issue and what else can cause the car to run lean like that? Thanks for any ideas.

Online kelso840

Re: Engine hesitation
« Reply #10 on: 09:53:45 AM / 08-May-17 »
Could a malfunctioning TPS be the reason it isn't sending enough fuel?

Also, is the hesitation occurring at a certain RPM or is it more conditional, like when you mash on the throttle from idle?
Infrequently driving an s12.

Offline deucekazoo

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Re: Engine hesitation
« Reply #11 on: 10:00:57 AM / 08-May-17 »
I was thinking that also about the TPS. I need to look in the book on how to diagnose it. The problem happens when I start to take off from a light. It takes off fine but then I would say 10 seconds into it, it goes lean. Then it hesitates, bucks, then sometime I shift and it takes off again or I just step on it more, give it a few seconds and it then takes off. So like you mentioned it could be the TPS. I will check that first.

Online kelso840

Re: Engine hesitation
« Reply #12 on: 07:29:19 AM / 09-May-17 »
Try disconnecting that bad boy and see what happens. If it runs the same you know it wasn't doing much.
Infrequently driving an s12.

Offline deucekazoo

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Re: Engine hesitation
« Reply #13 on: 08:08:16 AM / 17-May-17 »
Fixed the hesitation over the weekend. I pulled all the plugs apart on the engine harness and cleaned them. I think my issue was 3 of the 4 intake plugs were loose again. I tightened them down, cleaned all the connector pins, and made some new MSD plug wires. One of those fixed my issue. It runs nice and strong now.
This is the third time I had to tighten the plugs. If they loosen up again, not sure what to do but I hope this time tightening them down will be the charm.
I am guessing there was carbon buildup on the threads not letting the plugs get seated. I will run the car and check them in a month to see if they loosened up again.