map adjuster questions

Performance mods and Advanced Stroker discussion.
LeviPittman
Noob
Noob
Posts: 14
Joined: December 14th, 2011, 4:06 pm
Stroker Displacement: 278CI
Vehicle Year: 1990
Vehicle Make: jeep
Vehicle Model: comanchee

map adjuster questions

Post by LeviPittman »

finally got our 1990 4.6 mj running after sending it to the shop, now im having an entirely new problem.

im running 24lb venom injectors but seems like its running lean between 1900 and 2500rpm

i built the map adjuster from dino salva and ive got it hooked to the purple and white wire going into the map sensor and the adjuster has a toggle to switch between stock and adjusted volts but when i toggle the voltage to the adjusted voltage the engine will only sputter ... whats going on here? has anyone else had this problem?

is there a better map adjuster?

the circuitry in mine SEEMS to be fine because when i turn the potentiometer up and down the voltage follows

have i got it hooked up right? ive got 12v going into the box the ground grounded to the body and the feed voltage going into the switch

im running the stock renix system if that matters

id also like some help hooking up an AFR guadge too

thanks
levi and luke
User avatar
Cheromaniac
I live here
I live here
Posts: 3180
Joined: March 8th, 2008, 12:58 pm
Stroker Displacement: 4563cc
Vehicle Year: 1992
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: Cyprus
Contact:

Re: map adjuster questions

Post by Cheromaniac »

Something's not right. Did you check the voltage going into the MAP sensor from the MAP adjuster? You might want to check your wiring against the schematic that I put up on this page:

http://www.angelfire.com/my/fan/MAP_adjuster.html

My own MAP adjuster has been working flawlessly for more than 8 years.
1992 XJ 4.6 I6 - 5MT - Stroker build-up, Stroker "recipes" Sold
1995 Mustang GT - 4AT - Modded Sold
2006 Mustang GT - 5MT - Modded Midlife Crisis Car :mrgreen:
LeviPittman
Noob
Noob
Posts: 14
Joined: December 14th, 2011, 4:06 pm
Stroker Displacement: 278CI
Vehicle Year: 1990
Vehicle Make: jeep
Vehicle Model: comanchee

Re: map adjuster questions

Post by LeviPittman »

yeah the voltage adjusts as i turn the potentiometer (that's schematic i used to built it) so that part i know is working .... it only sputters though when i flip the switch over to the adjuster...
i even went so far as to check the stock voltage going into the map sensor and to set the adjuster to that voltage and it still only sputters BUT when i throw the switch itll fire up in less than two revolutions of the starter:(

this problem sux cause this is the only trouble im having and i know theres more power in this engine but i cant tap it until i get to where i can adjust the fuel curve

im gonna take the thing off tomorrow and make sure im getting a good connection

one question about the stock voltage i read somewhere that it goes up and down is that true or does it remain static at 5v?
thanks
Levi and Luke
User avatar
Cheromaniac
I live here
I live here
Posts: 3180
Joined: March 8th, 2008, 12:58 pm
Stroker Displacement: 4563cc
Vehicle Year: 1992
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: Cyprus
Contact:

Re: map adjuster questions

Post by Cheromaniac »

The input reference voltage remains static at 5v but the output voltage from the MAP sensor (middle wire) varies according to absolute pressure inside the intake manifold.
It does sound like you have a faulty connection somewhere.
1992 XJ 4.6 I6 - 5MT - Stroker build-up, Stroker "recipes" Sold
1995 Mustang GT - 4AT - Modded Sold
2006 Mustang GT - 5MT - Modded Midlife Crisis Car :mrgreen:
User avatar
cruiser54
Donator
Donator
Posts: 204
Joined: November 3rd, 2009, 4:38 pm
Stroker Displacement: 4.6
Vehicle Year: 1990
Vehicle Make: Jeep
Vehicle Model: Comanche
Contact:

Re: map adjuster questions

Post by cruiser54 »

I've used this guy's throttle bodies before with great results. Check out his MAP adjuster.

http://www.strokedjeep.com/regulator.html
Cruiser's Mostly Renix Tips can be found here :
www.cruiser54.com
Wanna view my technical photos? WARNING: Renix heavy!!
http://www.cherokeeforum.com/g/album/1725214
LeviPittman
Noob
Noob
Posts: 14
Joined: December 14th, 2011, 4:06 pm
Stroker Displacement: 278CI
Vehicle Year: 1990
Vehicle Make: jeep
Vehicle Model: comanchee

Re: map adjuster questions

Post by LeviPittman »

i just read on that link that it changes the pulse width at WOT if this is true then it wont help me ??
im only having trouble at about 1/4-1/2 throttle and then only below 2800rpms and above 1800

ill check the connections again tomorrow though
User avatar
SilverXJ
Global Moderator
Global Moderator
Posts: 5789
Joined: February 14th, 2008, 7:14 am
Stroker Displacement: 4.6L
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: Radford, Va

Re: map adjuster questions

Post by SilverXJ »

That is correct. The MAP adjuster only works at WOT. However I think you have another issue someplace
User avatar
Cheromaniac
I live here
I live here
Posts: 3180
Joined: March 8th, 2008, 12:58 pm
Stroker Displacement: 4563cc
Vehicle Year: 1992
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: Cyprus
Contact:

Re: map adjuster questions

Post by Cheromaniac »

LeviPittman wrote:i just read on that link that it changes the pulse width at WOT if this is true then it wont help me ??
The MAP adjuster will only change the injector pulse width (and AFR) when the engine computer is in open loop mode (>70% throttle, warm-up, and deceleration) and not using the O2 sensor output voltage as feedback. Since your problem is occurring at smaller throttle openings, you may have a problem with either the O2 sensor or the TPS.
1992 XJ 4.6 I6 - 5MT - Stroker build-up, Stroker "recipes" Sold
1995 Mustang GT - 4AT - Modded Sold
2006 Mustang GT - 5MT - Modded Midlife Crisis Car :mrgreen:
LeviPittman
Noob
Noob
Posts: 14
Joined: December 14th, 2011, 4:06 pm
Stroker Displacement: 278CI
Vehicle Year: 1990
Vehicle Make: jeep
Vehicle Model: comanchee

Re: map adjuster questions

Post by LeviPittman »

ok well i didnt replace either of those when i swapped out the engine .... do you have a ohm value for the tps and a way to check the O2 sensor?

also do they make a wide band O2 for the renix system and would that make a difference ?
User avatar
SilverXJ
Global Moderator
Global Moderator
Posts: 5789
Joined: February 14th, 2008, 7:14 am
Stroker Displacement: 4.6L
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: Radford, Va

Re: map adjuster questions

Post by SilverXJ »

LeviPittman wrote:ok well i didnt replace either of those when i swapped out the engine .... do you have a ohm value for the tps and a way to check the O2 sensor?
If its for the renix check here: http://www.lunghd.com/Tech_Articles/Eng ... ostics.htm
also do they make a wide band O2 for the renix system and would that make a difference ?
A wideband is not tied into the factory PCM, nor does it replace the stock O2 sensor.
LeviPittman
Noob
Noob
Posts: 14
Joined: December 14th, 2011, 4:06 pm
Stroker Displacement: 278CI
Vehicle Year: 1990
Vehicle Make: jeep
Vehicle Model: comanchee

Re: map adjuster questions

Post by LeviPittman »

ok so i figured out what was going on with the map adjuster on the 1990 comanchee the 5v feed is the red wire with the white stripe i had it hooked to a solid purple wire which was the output to the injectors ....
HOWEVER after setting the voltage to 5.2v it still sputters and in the exact same place now what should i try??
User avatar
cruiser54
Donator
Donator
Posts: 204
Joined: November 3rd, 2009, 4:38 pm
Stroker Displacement: 4.6
Vehicle Year: 1990
Vehicle Make: Jeep
Vehicle Model: Comanche
Contact:

Re: map adjuster questions

Post by cruiser54 »

LeviPittman wrote:ok so i figured out what was going on with the map adjuster on the 1990 comanchee the 5v feed is the red wire with the white stripe i had it hooked to a solid purple wire which was the output to the injectors ....
HOWEVER after setting the voltage to 5.2v it still sputters and in the exact same place now what should i try??
I would replace the O2 sensor just cuz. I'm also suspicious of the TPS as they had a high failure rate. Here are some simple instructions on how to adjust/tst the TPS. Be sure to do the sensor ground test in the beginning.

RENIX TPS ADJUSTMENT

Before attempting to adjust your TPS be sure the throttle body has been recently cleaned.
It's especially important that the edges of the throttle butterfly are free of any carbon build-up.

IMPORTANT NOTE: Using the positive (red) lead of your ohmmeter, probe the B terminal of the flat 3 wire connector
of the TPS . The letters are embossed on the connector itself.
Touch the black lead of your meter to the negative battery post.
If you see more than 1 ohm of resistance some modifications to the sensor ground harness will be
necessary. The harness repair must be performed before proceeding.
I can provide an instruction sheet for that if needed.

MANUAL TRANSMISSION:

RENIX manual transmission equipped XJs have a three-wire TPS mounted on the throttle body.
This manual transmission vehicle TPS provides data input to the ECU. The manual transmission
TPS has three wires in the connector and they're clearly embossed with the letters A,B, and C.

Wire "A" is positive.
Wire "B" is ground.

Key ON, measure voltage from "A" positive to "B" ground by back-probing the connectors..
Note the voltage reading--this is your REFERENCE voltage.

Key ON, back-probe the connector at wires "B" and "C". Measure the voltage. This is your
OUTPUT voltage.
Your OUTPUT voltage needs to be seventeen percent of your REFERENCE voltage. For
example: 4.82 volts X .17=.82 volts. Adjust the TPS until you have achieved this percentage. If
you can't achieve the correct output voltage replace the TPS and start over.

AUTOMATIC TRANSMISSION:

RENIX automatic transmission equipped XJs have a TPS with two connectors. There is a flat three-
wire connector, same as the manual transmission vehicles have, and it is tested the same as the
manual transmission equipped vehicles--FOR ENGINE MANAGEMENT RELATED ISSUES.

However, the automatic TPS also has a square four-wire connector clearly embossed with the letters
A,B,C, and D. It only uses three wires and provides information to the Transmission Control Module.

Key ON, measure voltage between "A" positive and "D" ground. Note the voltage. This is your
REFERENCE voltage.

Back-probe the connector at wires "B" and "D". Measure the voltage. This is your OUTPUT
voltage. Your OUTPUT voltage needs to be eighty-three percent of your REFERENCE voltage.
For example 4.8 volts X .83=3.98 volts. Adjust the TPS until you have achieved this percentage.
If you can't, replace the TPS and start over.

So, if you have an automatic equipped XJ your TPS has two sides--one side feeds the ECU, and
the other side feeds the TCU. If you have TRANSMISSION issues check the four-wire
connector side of the TPS. If you have ENGINE issues check the three-wire connector side of
the TPS.

For those with a MANUAL TRANSMISSION--the TPS for the manual transmission XJs is
stupid expensive. You can substitute the automatic transmission TPS which is reasonably priced.

Revised 11-28-2011


And since you've got a Renix Jeep, this is a proven way to improve the poorly designed grounding system which affects the sensor signals to the ECU and the ECU grounds, too.
Renix Ground Refreshing

The Renix era XJs and MJs were built with an under-engineered grounding system for the engine/transmission electronics. One problem in particular involves the multiple ground connection at the engine dipstick tube stud. A poor ground here can cause a multitude of driveabililty issues, wasted time, and wasted money replacing unnecessary components.

The components grounding at the dipstick tube stud are:

Distributor Sync Sensor, TCU main ground, TCU “Shift Point Logic”, Ignition control Module, Injectors, ECU main ground which other engine sensors ground through, Oxygen sensor, Knock Sensor, Cruise Control, and Transmission Sync signal. All extremely important stuff.

The factory was aware of the issues with this ground point and addressed it by suggesting the following:

Remove the nut holding the wire terminals to the stud. Verify that the stud is indeed tightened securely into the block. Scrape any and all paint from the stud’s mounting surface where the wires will attach. Must be clean, shiny and free of any oil, grease, or paint.

Inspect the wire terminals. Check to see that none of the terminals are crimped over wire insulation instead of bare wire. Be sure the crimps are tight. It wouldn’t hurt to re-crimp them just as a matter of course. Sand and polish the wire terminals until clean and shiny on both sides. Reinstall all the wires to the stud and tighten the nut down securely.

While you’re in that general area, locate the battery negative cable which is fastened to the engine block just forward of the dipstick stud. Remove the bolt, scrape the block to bare metal, clean and polish the cable terminal, and reattach securely.

Another area where the grounding system on Renix era Jeeps was lacking is the engine to chassis ground. There is a braided cable from the back of the cylinder head that also attaches to the driver’s side of the firewall. This cable is undersized for it’s intended use and subject to corrosion and poor connections at each end.

First off, remove the cable end from the firewall using a 15mm wrench or socket. Scrape the paint off down to bare metal and clean the wire terminal. Reattach securely.
Remove the other end of the cable from the rear of the head using a 3’4” socket. Clean all the oil, paint and crud from the stud. Clean the wire terminal of the cable and reattach securely.

A suggestion regarding the braided cable:
I prefer to add a #4 Gauge cable from the firewall to a bolt on the rear of the intake manifold, either to a heat shield bolt or fuel rail bolt. A cable about 18” long with a 3/8” lug on each end works great and you can get one at any parts store already made up. Napa has them as part number 781116.

A further improvement to the grounding system can be made using a #4 cable, about 10” long with 3/8” terminals at each end. Attach one end of this cable to the negative battery bolt and the other end under the closest 10mm headed bolt on the radiator support just forward of the battery. Napa part number 781115.



If you want to upgrade your grounds and battery cables in general, contact Jon at www.kelleyswip.com. He makes an incredible cable upgrade for a very reasonable price.


Revised 11-28-2011
Cruiser's Mostly Renix Tips can be found here :
www.cruiser54.com
Wanna view my technical photos? WARNING: Renix heavy!!
http://www.cherokeeforum.com/g/album/1725214
LeviPittman
Noob
Noob
Posts: 14
Joined: December 14th, 2011, 4:06 pm
Stroker Displacement: 278CI
Vehicle Year: 1990
Vehicle Make: jeep
Vehicle Model: comanchee

Re: map adjuster questions

Post by LeviPittman »

ok buddy thanks ill try that tomorrow all that grounding stuff has already been done but the tps thing hasnt
NelsonATC
Donator
Donator
Posts: 33
Joined: May 6th, 2012, 6:54 pm
Stroker Displacement: 4.6
Vehicle Year: 1980
Vehicle Make: Jeep
Vehicle Model: CJ7

Re: map adjuster questions

Post by NelsonATC »

LeviPittman wrote:yeah the voltage adjusts as i turn the potentiometer (that's schematic i used to built it) so that part i know is working .... it only sputters though when i flip the switch over to the adjuster...
i even went so far as to check the stock voltage going into the map sensor and to set the adjuster to that voltage and it still only sputters BUT when i throw the switch itll fire up in less than two revolutions of the starter:(

this problem sux cause this is the only trouble im having and i know theres more power in this engine but i cant tap it until i get to where i can adjust the fuel curve

im gonna take the thing off tomorrow and make sure im getting a good connection

one question about the stock voltage i read somewhere that it goes up and down is that true or does it remain static at 5v?
thanks
Levi and Luke

Did anyone find a viable solution to this? I am having the exact same issue, OBD1
NelsonATC
Donator
Donator
Posts: 33
Joined: May 6th, 2012, 6:54 pm
Stroker Displacement: 4.6
Vehicle Year: 1980
Vehicle Make: Jeep
Vehicle Model: CJ7

Re: map adjuster questions

Post by NelsonATC »

cruiser54 wrote:I've used this guy's throttle bodies before with great results. Check out his MAP adjuster.

http://www.strokedjeep.com/regulator.html
And this is the MAP adjuster I am using
Post Reply

Who is online

Users browsing this forum: Amazon [Bot], Google [Bot] and 11 guests