• Notice for iPhone users: DO NOT use the image size reduction option when uploading photos to the forum. This causes portrait images to post as landscape. We have added a warning to the image insert pop-up as well.

Another Scrambler Purchase/Road Trip - UPDATE- BODY ON FRAME AGAIN

Craner8 said:
Did you get the f.I. from Hesco? If yes does it crank for three seconds before it starts? Mine does every time. Wondered if its the nature of the system. I would have thought it would start with a bump of the key. Thoughts?
Click to expand...

If the Hesco is based on the 87-90 Renix, then yes, that's normal. The Renix ECU was designed to turn over a couple times before it would fire off. It had to "see" the CPS 3 times before lift off, IIRC.
 
Craner8 said:
Did you get the f.I. from Hesco? If yes does it crank for three seconds before it starts? Mine does every time. Wondered if its the nature of the system. I would have thought it would start with a bump of the key. Thoughts?
Click to expand...

Yes, my MPI came from Hesco. But, mine starts immediately. As soon as you turn the key it fires up. After it starts, it idles up to around 1200 RPM, then slowly idles back down in stages to around the base idle of 750. After it returns to base idle after the initial start up "flair", it idles a little rough for about 20 seconds. Then, it magically clears up and runs perfect.

I talked to the people at Hesco about this issue, they said the idle air control was probably not flowing enough air at initial cold start. Per their recommendation, I drilled a hole in the throttle plate to allow more air flow at idle. This cleared it up some. I might be able to enlarge the hole I drilled already slightly, to allow a little more air flow at cold start idle. But. I am used to it now.
 
Cincyjeeprs said:
If the Hesco is based on the 87-90 Renix, then yes, that's normal. The Renix ECU was designed to turn over a couple times before it would fire off. It had to "see" the CPS 3 times before lift off, IIRC.
Click to expand...

I am pretty sure the Hesco kit is based off of the "post" Renix system:cheers:
 
Hesco MPFI kit is based off of a 94 HO system...
 
I would think something is not right if an EFI system is cranking for 3 seconds before starting. I've also never heard of the rough idle issue like this before. If it was all that common, I figure we'd have a number of people posting to ask about it after installing their kits. :shrug:
 
bigwalton said:
I would think something is not right if an EFI system is cranking for 3 seconds before starting. I've also never heard of the rough idle issue like this before. If it was all that common, I figure we'd have a number of people posting to ask about it after installing their kits. :shrug:
Click to expand...

Well, at least mine starts right up LOL:D:cheers:

As for the "temporary slightly rough idle after initial start up flair", I have two theories:

1) I need to drill the hole in the throttle plate slightly larger to allow more airflow into the throttle body while the throttle plate is closed then what the IAC is allowing. If you slightly press the open the throttle plate during the rough idle, it instantly goes away. It could be "starving" for air:shrug:

2) Maybe the regulator on the fuel rail is leaking down slightly when the vehicle is shut off:shrug: I don;t think this is the issue, as the fuel pressure checks out OK at the rail, and it starts up very easy.

It usually only does the rough idle on a cold start. But, sometimes it will do it on a hot restart after long highway driving. But, after the 20 or so seconds of rough idle, it magically clears up, like it is possessed:crazy:

I had reported my issues on the Hesco sight, and they kind of offered some help. Now, they wont let my posts show up or answer my last question:( Last response I got was "you installed it wrong":shrug: They might have got mad at me because i commented how my "factory computer controlled BBD Carb equipped 83 Scrambler starts up better then my fuel injected one":shrug:

I have went back and double checked my entire installation, step by step per the Hesco/Mopar instruction manual, everything is correct. Intake/exhaust manifold bolts still tight, all fuel line clamps still tight, distributor installed correctly, etc, etc, etc.

The only thing I can figure is the IAC issue. That is what the Hesco people seem to think. I have hooked the diagnostic port up to three different scan tools and I have no codes:crazy:
 
Then mine must be the Renix system. It never fails to start, but always cranks and cranks and cranks then fires. And yes it idles rough initially too, then clears up after about 20 seconds.
 
When my 91 xj would crank for longer than it should, it was always the fuel pressure regulator On the fuel rail. replace it and worked like a charm.
 
A few videos of the red Scrambler trail riding from this past weekend. Nothing too hard core. Street pressure in the tires and the front sway bar hooked up:popcorn:







 
Last edited:
Best Part

This is the best part of the build. ;): cheers:

:wave:
 
I was going to send a PM about this but, since the subject came up...

the other night I sold a few of the last remaining parts from my YJ parts Jeep to another local Jeeper.. he came to the house to pick them up and was checking out my project while there.. he says "yeah, there's this guy over at Bogs and Boulders from the SMJC that has a really nice red one, and he's not afraid to wheel it"...

I said, "yeah.. I know Raymond" (my connection to someone famous ;) )
 
Bushmaster6 said:
I was going to send a PM about this but, since the subject came up...

the other night I sold a few of the last remaining parts from my YJ parts Jeep to another local Jeeper.. he came to the house to pick them up and was checking out my project while there.. he says "yeah, there's this guy over at Bogs and Boulders from the SMJC that has a really nice red one, and he's not afraid to wheel it"...

I said, "yeah.. I know Raymond" (my connection to someone famous ;) )
Click to expand...

:D Me, famous:D

The bright red Scrambler out on the trails does seem to make an impression, the driver, not so much:cheers::D
 
You must log in or register to reply here.
Back
Top