Question about 1996 GMC Yukon

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97 chrysler concorde 3.5 bad accel off idle , ok on high end

Replace computer
replace map
replace o2
replace wires
good fuel volume test
good pressure 43 psi
replaced intakes
no hard starts
starts just fine

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Check your air intake control switch: it is on the manifold and, is attached to a flap inside the intake; this switch's flap should be easily moved by the air from the aircleaner and, tells the engine computer that you have the right amount of air coming into the engine for fast acceleration if it fails the engine computer will not know the amount of air available to sustain rapid spark speed lastly check the installation of your air filter I have seen very dirty ones and, some inserted upsidedown there is an arrow that should point to the engine

Posted on May 10, 2009

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I have a 1990 jeep wrangler 4 banger 2.5l manual tranny She runs and starts fine but I can only drive about 1 mile before it starts losing power. It gets to the point where I'll be in first gear trying to...


do a 60k tune up first, all below assumes you did, spark parts, filters. dah?
first off the engine EFI runs a map sensor, (called speed density system)
so that means if the engine can pump air (compression tests PASS)

the MAP see that, air flow (calcs) and matches air with proper fuel.
1990 is a vary bad year, it has the horrid, Renix french pos EFI system. (owned 2, can taLK days on this ecu FROM H3LL)

but there is no CEL lamp, nor any scan tool , that will work here.
(unless you can find a working DRB tool, ) NO FLASH CODES !!!
above poster never seen RENIX, so.. .answers wrong. ITS OK.
1993 this changed (Chrysler) and started OBD1 ECU which we can scan easy. (innova 3140)

all this means is you must be smarter than the average bear.
are you>? got tools, meters. and all that? you will need it.
and a FSM book or login to alldata.com like we do.


if compression test pass, and vacuum at 19" idle and gunned throttle drops low fast and if you release throttle it goes why high fast 25inches>? and goes to 19inchs again, the engine is ok and cat not melted, all that in 5min work (vacuum tests) and vacuum not bouncing? 1 glance, no its steady vavcuum.
so I wave my magic wand, go, gee engine is ok.
i then check fuel pressure use a REAL gage.
it idle and throttle gunned. for spec pressures.

if all that pans out> whats next? well EFI is next,.
i check the MAP sensor voltage at 3 points.
key on, idle and gunned. for spec, readings. if not map is bad. or just clogged.
check all the other sensor by hand is next. and ill not attempt do post what ever mech ,knows here, "basics"
a volt meter , you can check them, ECT, IAT, etc.

my wild guess low fuel pressure. (BASE ON OK 1 MILE)
or FPR stuck wide open' (bad fuel pump reg)
or a bad wire to fuel pump, such that pump does not receive full 12vdc power.

here is map readings, ill post this because many books fail to show it.
http://www.fixkick.com/sensors/my-map.html#Jeep

if input to map is good, but output wrong, the map is DOA.

Mar 09, 2015 | 1990 Jeep Wrangler

1 Answer

96 Chrysler concorde 3.5L, I have consistantly pull the gas after start or it won't stay started. As is the pcm forgot the idle. Once its warmed up it will have a rough idle and eventualy die. What...


I have a 1996 LHS, same 3.5L engine, loved the riding and smoothness when i bought it 2 years ago..... F@#$%ng money pit, a POS scam artist of a mechanic charged me 4200 for new front end suspension a year ago which is already shot again, after that i insisted on doing everything on this car myself. As i have no professional training nor do i have a stocked garage this goes without saying is a daunting task.I recommend buying or borrowing(local library) a Chilton and/or Haynes manual. The Chrysler Concorde is the same car different body style as my LHS, a Piece of something.. I'm in the midst of learning about the idling, as i have an opposite problem with too high rpms.

So far, i've concluded that some sensors only malfunction during certain conditions, i.e. cooling temperature sensor that activates fans, also can cause rich or lean fuel/air mixtures. It sounds to me like something is inducing a rich fuel mixture(high rpms) and your PCM (LHS' under air filter compartment) is overcompensating and has stored into its memory leading to a lean running car. I know it doesn't answer your question but hopefully it'll spark an idea. when i figure it out exactly i'll let you know.
Jalael Sabri

Feb 26, 2012 | 1996 Chrysler Concorde

1 Answer

01 ford focus has poor acceleration off idle, sounds lean


Check o2 sensors they control your fuel delivery

Dec 18, 2011 | Ford Focus Cars & Trucks

1 Answer

I got a P0601 DTC on my 2001 Chrysler Voyager 2.4. I replaced the PCM and immediately got a P0172 with a rough idle. I replaced the O2 sensors but still have the same problem with same DTCs.


OK. Let's see here...with the code P0601 you had no choice but to replace the PCM. Now here is the kicker...Was it properly programmed before you started the engine up? I just have to ask because I have seen things like this happen with PCM replacements when the PCM did not get programmed properly or when people switch out used PCM's from other vehicles that are not programmed with the correct software for the vehicle it is going into.

Now, with all that said:
P0172-1/1 FUEL SYSTEM RICH
The O2 sensors are RARELY - IF EVER the cause of this code. It does not surprise me that replacing the O2 sensors did not fix it.

Either the O2 sensor signal circuit is shorted to voltage, or you have something wrong with your engine that is causing the engine to run extremely rich. Any way you look at it, your O2 sensor signal voltage is way too high. This is why O2 sensor failures do not usually cause this code. When O2 sensors fail, they do not produce voltage like they should and you will get LEAN codes, not RICH codes.

Anyway, this code is more likely to be caused by a bad engine coolant temperature sensor (ECT), a bad manifold absolute pressure sensor (MAP), a leaking fuel pressure regulator diaphragm, leaking injectors, etc. or something could be shorting out the reference voltage to the MAP sensor and the Throttle Position Sensor.

Please also review this article:

What Else Could Be Wrong?

Sep 20, 2011 | Chrysler Voyager Cars & Trucks

1 Answer

97 Chrysler 2.5L runs bad when warm stalls and knocks no MIL


It sounds like you did not change those intake manifold gaskets and they are not completely sealing the intake and causing a vacuum leak and the MAP sensor will read high in voltage and cause the bad idle.

Oct 29, 2009 | 1997 Chrysler Sebring

1 Answer

On a 1996 chrysler concorde I was told to disconnect a bad catlitic? converter to get around high prices for a young lady I am trying to help with no cash.after replaceing it with strait pipe the car idle...


By connecting the O2 sensor wires together you have created a short to ground in the O2 heater circuit blowing the related fuse that is usually on the ASD circuit. Without a converter the check engine light will come on since the O2 sensors are no longer doing their job. If she doesn't mind the light being on, disconnect the sensors leaving all the wires an open circuit and replace the affected fuse. You can't trick the computer since it looks for a ramp voltage and compares the upstream to downstream O2 sensors to determine the proper air fuel ratio for any given driving condition. I hope this helps.

Oct 19, 2009 | 1996 Chrysler Concorde

1 Answer

1999 Chrysler Cirrus Lxi 2.5l high rpm


The throttle position sensor may be misaligned. This tells the computer how much throttle is being applied, and when they go bad, or come out of alignment, the idle tends to get up there. If that's not the issue, remove your air cleaner, the housing and everything until you get to the MAP sensor. Give it a good spray with carb cleaner, let it dry and replace the air cleaner with a new one. If the MAP sensor detects minimal air flow, the computer jacks up the idle to compensate.

Nov 07, 2008 | 1999 Chrysler Cirrus

2 Answers

MISFIRE ON CYLINDER 5. I have changed plugs, wires, coil pack, fuel injector, and ECU unit. I have had two compression tests and it was put on a diagnostic machine. Everyone is scratching their heads as...


Same problem. 94 LHS 3.5L engine. Noticeable rythmic misfire at idle. Looks like cyl 5. When I pull the injector connector off of cyl 5 the idle rythm does not change. It does if i pull the inj connector off of any other cylinder. Spark OK. Injector ok using seperate 12vdc supply (clicks). Connector to injector has pulses on it verified with a test light. Inj coil resistanceis 12 ohms, exactly what it should be.

Still need to check compression and intake manifold gasket

websales@shaw.ca

Jul 21, 2008 | Chrysler Concorde Cars & Trucks

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