looking for a Jeep stroker expert in Los Angeles

[vwtipeii]

Hi everyone,

I have a 94 YJ with a 4.7 or 4.8L stroker I purchased from 505 performance. Long story short after 3 years I can't get her to run cool under load. We have done everything possible as far as cooling and engine electrical to the Jeep. I mean everything! We are thinking it's either fuel and or timing. However witht he stock ECU timing can't really be adjusted and either can fuel pressure. yes, we have cut off the tooth in the distributer and tried to turn it to get better timing but the ecu keeps changing timing to 12 degrees not matter what. I have the 24lb injectors too. Bottom line I need to get the engine out and on a dyno on a stand to see if the issue is in my ECU or not. Any references for a Los Angeles based Jeep stroker expert is highly appreciated.

Thanks,
B

[jsawduste]

What is your cooling system ? Tire size, transmission and gearing ? What fuel pressure ? Engine set up ?

Many us run the SBEC OBD1 ECM`s with no problem. No it is not optimum but it does work.

There are several folks I can rattle off but won`t waste there time till the basics are covered.

[Cheromaniac]

yes, we have cut off the tooth in the distributer and tried to turn it to get better timing but the ecu keeps changing timing to 12 degrees not matter what.

The ignition timing is fixed in the ECU and you can only advance/retard it either by slotting the CPS bolt holes and moving the sensor, or by reprogramming the ECU.
Rotating the distributor merely changes the synchronization of the injector pulse with the valve timing events.
I don't think your problem is with the timing but is more likely to be with the engine running lean.
I suggest you install a wideband O2 sensor to find out what's going on with the A:F ratios and work from there.

[vwtipeii]

I have had 3 mechanics go through everything so I don't want to list everything again... I am at the point where we need to pull the engine and put it on a stand to see if it's my ecu or not.

What's been done:
New griffin all aluminum radiator
new fan shroud
double checked to ensure fan is mounted the right way (pulling air)
New electric pusher mounted to the front of the AC condenser in front of radiator
new high flow water pump
new hoses
new high flow Hesco water pump housing
new 180 degree thermostat
new heater core
new distributor, cap and rotor (tooth has been cut from the distributor to allow for manual adjustment of timing however computer always moves timing back to 12 degrees)
new coil
new autometer gauges
new sending units
new stand alone engine wiring harness (hand made as hesco was back ordered)
new injectors 24lb I think
I think we are replacing the fan clutch again just to double triple check.

drive train: 4.88 gears. ax-15 manual. 37" MTR's

Jeep runs great around town...any time i climb a hill she gets hot. We have done compression tests, leak down tests. Rings are good, compression is good.

i just need the name of a shop in LA where we can pull the motor and run it on a dyno to isolate the problem.
Thanks,
B

[nicpaige]

I'm wondering why you think running it on a dyno is going to tell you anything you cant troubleshoot in the vehicle?

[jsawduste]

The griffin is not doing you any favors. The electric fan pusher is not needed. The 185 is meaningless.

The engineers at Mopar spent millions of dollars designing a cooling system that will work in the heat of the desert and the colds of the Artic. There is little we mere mortals can do to improve it. Using typical auto parts store stuff is not factory.

Double check the fan pitch as the 4.2 v belt was a CW rotation whereas the serp belt is CCW. The blades are pitched to reflect the direction.

My strokers are set up with a factory fan, factory clutch, factory shroud, factory radiator, ..or a CSF 2578....factory thermostat, cap and factory coolant. All spun with a factory waterpump. They never overheat even the height of summer lugging between the trees or blasting up the dunes. To add even more heat the crank sensor is normally modded to add timing and the IAT relocated which does the same thing.

If I gave you the contacts your looking for in the LA area the first thing they would do is dump the crap your currently running and revert back to the factory parts.

If the problem still persists then a check of AFR would be in order followed by a compression test.

[6TIME]

How hot is it getting? High on the temp gauge or is it boiling over?

[vwtipeii]

I'm wondering why you think running it on a dyno is going to tell you anything you cant troubleshoot in the vehicle?

running it on a bench with its own cooling will help determine if the problem is with my cooling system.

[jsawduste]

No it wont unless you can simulate vehicle dynamics. Be curious to see if that aluminum radiator is filled with electrolysis blockages from poor grounding. Put a stock OEM radiator in it. Not a parts store made in China unit but one
that is made of copper and brass with an OEM part number

[SilverXJ]

I agree. I don't think running it on a dyno will prove anything. Too may variables involved and not just the cooling system itself.

Have you always had high flow water pumps with the over heating issue?

[nicpaige]

I would hook a wideband up and save a few datalogs to at least rule out a/f ratio problems.

[vwtipeii]

How hot is it getting? High on the temp gauge or is it boiling over?

It has boiled over when wheeling on steep climbs. on the highway I try to keep it on the bottom of the red line or I pull over. I hate it.

[nicpaige]

Think of it this way. If you put it on an engine dyno and they hook it up to there 700 dollar high efficiency radiator and all of a sudden it doesnt overheat what did you learn? That radiator wont fit in your jeep. That radiator isnt covered up by a firewall, fenders core support, a hood and grill. It wont tell you anything about your ECU either. I would really concentrate on verifying the temp gage with a known good mechanical gage. Also as I said before a/f ratio and if possible EGT and all these can be checked without yanking the engine and paying someone to put it on a dyno. What temps does it run just cruising around, stop and go traffic? Does it exhibit these same problems in cool or hot outside temps? I understand your frustrated but I have no idea why any mechanic would recommend putting it on a dyno other than to lighten your wallet.

[SilverXJ]

Have you always had high flow water pumps with the over heating issue?

[Cheromaniac]

I would hook a wideband up and save a few datalogs to at least rule out a/f ratio problems.

x3