Jeep Strokers

Hi all,

This is my first post and I hope that you guys well be able to help me with your great knowledge. 
I'm not really a technical guy, so bear with me if I sounded stupid ! 


Few months ago, I bought a brand new Golen 4.6L stroker engine. I used the engine for my 1998 Jeep Wrangler TJ Project.

Along with the engine, I also bought the following items:
* Roller Rocker Upgrade (it came preinstalled on the engine)
* Accel 62mm throttle body
* Accel 24lb Fuel injectors
* High Flow Water Pump
* 180 Thermostat

Other details:
- I'm running on 91 octane
- brand new but stock radiator and cooling components.
- 3" custom exhaust system all the way.
- I live in a hot tempreture region

The engine installation went fine thanks to the detailed installation instruction manual.

Problem description:
- once warm, the engine knock starts from as low as 1,500RPM.
- the knock happens only when the engine is underload. There is no knock when idle/cruising.

Things that were done so far:
1) After some investigation. We disocvered that the truck is running a PCM that does not support oxygine sensors. We replaced the PCM and installed two new oxygine sensors. This slightly affected the issue. The knock now starts from 1800-2000RPM

2) we installed AEM FIC 8 controller and sent the car for tuning. I was told by the tuner that the truck runs rich while idle and lean while on load. They tried to adjust this. They also adjusted the timing to 3 degree retard. This is the end results:
-the knock starts at 3000 rpm.
- the engine tempreture is much better.
- the engine have some hard time to start.
- when putting load on the engine, there is a brief moment where the rpm drops and the engine seems to get choked.

I stopped at this point unable to take decision on what to do next. So your advice is highly appreciated.

how does the engine fells like ?? is it strong or sluggish?
maybe the distributor is out of sync, that can cause engine knock(detonation)!

The engine feels strong. I like it more when I don't have the AEM plugged.
We tried to play With the distributor but it didn't help ..

Will adding a fuel regulator and a larger fuel pump help me with this issue ??

ossme wrote:Will adding a fuel regulator and a larger fuel pump help me with this issue ??

No. Your stock fuel pump is already man enough for the job, and the stock 49psi regulator is integrated with the fuel pump & gauge sending unit so it can't be changed. With 24lb Accel injectors and a 49psi regulator, the injectors will flow 25.5lb/hr so your engine shouldn't be running lean.
The base ignition timing should be 10*BTDC with maximum advance at 34*BTDC. Sounds like your timing and fuel curves are off. How does the engine perform with the stock PCM tune?

Knocking under load sounds to me like detonation. Moving your distributor won't change ignition timing, it will change fuel injector timing. try running high octane fuel and see if that helps.

dwg86 wrote:Knocking under load sounds to me like detonation. Moving your distributor won't change ignition timing, it will change fuel injector timing. try running high octane fuel and see if that helps.

I'm tried running 98 Ron ( 94 AKI) fuel. It helps, but the knock is still there. I can't seems to find octane booster but I would like to try that as well.

Running such a high octane is a pain because most (if not all) of the gas stations near offroad spots do not sell them ..

Cheromaniac wrote:

ossme wrote:Will adding a fuel regulator and a larger fuel pump help me with this issue ??

No. Your stock fuel pump is already man enough for the job, and the stock 49psi regulator is integrated with the fuel pump & gauge sending unit so it can't be changed. With 24lb Accel injectors and a 49psi regulator, the injectors will flow 25.5lb/hr so your engine shouldn't be running lean.
The base ignition timing should be 10*BTDC with maximum advance at 34*BTDC. Sounds like your timing and fuel curves are off. How does the engine perform with the stock PCM tune?

I'm Planning to buy a Fuel pressure gauge to check the if the pump is working properly. It is 15 years old pump and that is why I sometimes suspect that it might be defective.

Apart from the knock, My PCM runs much better with stock tuning. The engine feels more powerful and does not get chocked at low rpm.

I will try to connect a laptop to the AEM and extract the current tuning. I will hopefully post it tonight.

Ok, I'm supposed to post the AEM tuning details few days ago. But their software only works on Windows laptops. I own a mac ..

I will try to barrow a windows based laptop. Hopefully, I will be able to download the information today.

dang man, i feel your pain on the program only running on windows. i have an innovate wideband and logger and it only runs on windows too.

i can't help on your knock problem but i hope you get it figured out

superj wrote:dang man, i feel your pain on the program only running on windows. i have an innovate wideband and logger and it only runs on windows too.

i can't help on your knock problem but i hope you get it figured out

Yeah, I still wasn't able to source a windows based computer. I might end up buying a windows license to install it on my macbook just because of this ..

OK, I removed the AEM today and plugged my OBD II tool and Torque software.

I wasn't able to do many tests today. But here is what I found so far:

Fault Codes:

P0138 - Power Train / O2 sensor Circuit High Voltage (bank 1 Sensor 2)

Note: my Rear is disconnected.

Vehicle Test Results:

TID: $11 CID: $01
Max = 64
Current = 51
OK

TID: $13 CID: $01
max=53
Current = 255
Not OK

Other data:

C02 in g/km = 131.56g/km

Throttle Position:
12.55% @ idle
74% @ WOT

Timing Advance:
17 degree @ Idle
44 degree @ 3000rpm.

I received my Fuel gauge today. Hopefully, I will be able to test the fuel pressure within this week.

I still didn't get any Windows based laptop. So I purchased a copy of windows 7 and I'm planning to install it on my mac..

with the AEM installed. I have no knock issues. The engine runs fine until 3000rpm. But It struggles to reach the speed limiter after that. The engine basically don't like to run under load.

I'm ready to provide any type of data you guys need to diagnose my issue. So Please guys help !

Oh, and I also have an overheating issue. Here is the summary of what have been done so far to solve it.

ossme post 1 wrote:
So I replaced my stock radiator and fan with Griffin 3" Aluminum Core and Fix a Lite electrical fan.

Guess what ? I didn't gain any extra cooling! Not even 1 degree !

Actually, I think that I lost some. But I believe that is more to do with my "high flow water Bump".

Anyway, since my overheating problem doesn't seems to be from the radiator. I'm turning my attention to the thermostat and it's housing. Do you guys think that they can be restrictive enough to cause a an overheating issue ?

The truck currently idles at 106c (222.8F) and it raises under load. I want my tempreture to max at 105c (221F) under heavy load, a/c on, and with hot climate. Something that seemed to be achievable With my 13 yo engine and cooling system.


What I'm planning to do now?

1- Run without a thermostat to see if this solves anything.
2- try and change the heater core hoses as they might be plugged. ( I already deleted the heater core).

ossme Post 2 wrote:OK, here what I have done so far:

1. I removed the thermostat. No such a thing obstructing the coolant now..
2. I opened and cleaned all the pipes. I found some corrosion on the Heater ones. But not enough to cause overheating issues.

... and here are My Current Observations.

• At idle, and when the A/C is OFF, the truck idles at 89c (192.2F)
• At idle, and when the A/C is ON, the truck idles at 96c (204.8F)
• The top end temperature was not affected. I have not tried to drive with the A/C on yet.
• I had the courage to drive the car without the A/C and the temperature is lower across the RPM range. The max I got was 102c(215.6F) Driving 120 km/h (75mph) at 2900RPM. Pressing the engine will also push the temperature up.
• At low speed traffic, the temperature drops! the lowest I have seen so far is 86c (186.8F). Again, this is with the A/C off. The temperature also drops in the underground parking, which is cooler than the outside temperature.
• Without the thermostat, the temperature drops rapidly once the Jeep comes to a stop. It can go from 99c(210.2F) to 89c(192.2F) in matter of minutes!

This raised few questions in my mind:

Engine issue ?

• Is my engine producing an excessive amount of heat ?
• Do I need to change the oil type/brand ? I'm currently running 10w40 and for less than 1000 miles.
• Maybe the engine got plugged with corrosion ? should I flush it just in case?
• Maybe the fuel mixture is not good ? the engine is running lean at higher RPMs ? The engine does feel nice until about 2700rpm.

Water pump issues ?
I got this High flow water pump unit from Golen based on their recommendation. But I noticed before (with the stock cooling setup) that the temperature raises higher when at load when using the aftermarket water pump as apposed to stock unit. Should I go back to the stock unit and test ?

A/C Compressor issue ?
The difference between running with the A/C on or off is huge in my opinion. Some may argue that it is normal, but my old engine never had this problem. Running the A/C would of raised the temperature by 2~4c at max.

Aerodynamic issues?
Maybe my Winch is blocking the airflow at high speeds? I really doubt this as the heat issue started way before the winch. Also lots of people are running with larger winches without overheating issues.


So, What I'm planning to do now:

Do more testing. I will test it today with the A/C on. I will also try to push the engine and see the maximum temperature I get.

1. Engine tuning:
   • Change the oil to a Mobile 1. But Should I change the type as well?
   • Check the fuel pressure. (to make sure that the truck is not running lean).
   • Re-tune the AEM FI/C 8 using a better dyno shop. (provided that the fuel pressure is ok).
2. Swap the factory water pump back in.
3. Install a secondary Fan on the front of the Radiator that gets activated once the A/C is turned on.