Question about Jeep Cherokee

1 Answer

Ecu not giving signal to injectors?

Ecu not putting signal out to injectors vechile cranks but doesn't start,it does have puls from crank sensor but no feed or signal from ecu?

Posted by on

Ad

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • Jeep Master
  • 2,122 Answers

Hi Daw, As you've already checked the crankshaft sensor, sounds to me as if the problem may be from the camshaft pickup sensor. If that one also proves fine you'll need to have the anti theft system re-coded. The anti theft unit cuts the injection. Regards John

Posted on Jan 13, 2013

Ad

6 Suggested Answers

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Ad
emissionwiz
  • 76164 Answers

SOURCE: 2000 jeep cherokee starts then stalls in approx 3 sec 4.0 has new crank sensor

I am going to assume that it will not run even if you push on the accelerator pedal?
Can you install or attach an old timing light to the spark plug wires, turn it one and try to start it. The light should flash with the engine running, but if it shuts off at time of engine die, and the engine is still spinning, you are losing spark, My suggestion is the cranks shaft sensor on bell housing.
Second, install a pressure gage on the test port on the fuel rail and watch it as you start the engine, fuel pressure should not drop as the engine dies, if it does, the pump is not working correctly. There are two modes of power to that pump, one to start and timed, for only a few seconds to prime the system, and one to run continuously. Find the wires going to the pump at the tank. Connect test light to those wires and watch what happens during crank and at stall, You should not have the pump shut off and the engine dies.
If you have spark, and fuel pump working, when did you last change the filter,,but I put that LAST.
It has to be one or the other of these.
Good Luck

Posted on Aug 04, 2008

  • 1 Answer

SOURCE: 2000 chevy blazer, truck cranks

Does your battery go dead?

Posted on Dec 18, 2008

  • 1201 Answers

SOURCE: car has no spark or injector pulse(new ecm,crank sensor)

Check the fuse for the injectors, some vehicles have the injectors and coil running on the same circut, at the same time check the fuse for the ignition.

Posted on Jan 30, 2009

  • 16 Answers

SOURCE: 2002 Hyundai Elantra not starting

check fuel pump

Posted on Mar 14, 2009

  • 40 Answers

SOURCE: 1999 Altima will not start, no power to Crank Position Sensor

The crank sensor is only a reference and shouldn't cause it not to start. I would look elsewere for your problem ie camshaft position sensor which is built into the distributor. This is amore likely cause of your no start condition.

Posted on Aug 06, 2009

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Do the crank sensor operate the fuel injectors?


Not directly no. The crank position sensor tells the cars computer, ECU, where the engine rotation is, and the ECU pulses the injectors at the right time, then fires the spark plugs at the right time.

The crank position sensor is mounted in various locations by different manufacturers. In my Camry it is on the distributor shaft ! In your car it could be on the crankshaft nose or in some other place.
.

Jan 02, 2017 | Cars & Trucks

1 Answer

How do i fix to get signal from ECU to feed 6 injectors, permanent 12v are their.


You'll need a repair-shop manual to troubleshoot the engine computer and components.
The computer takes input from the crank and cam sensors (if equipped) and grounds the injectors when needed.

Mar 27, 2015 | Cars & Trucks

2 Answers

Hi I just fitted 1997 mpi engine to my daughters 1995 single point injection car and it won't start turns over good spark and fuel is pumping to rail if I put a drop of fuel I thrott body it...


Sounds like the injectors are not opening up to supply the fuel. I would verify the crank position sensor is working. That's what the ECU uses to know when to dump fuel. Did you change ECUs???

Dec 28, 2014 | Cars & Trucks

1 Answer

Jaguar xj sport 3.2 no spark or injector pulse


If ECU has crank signal and engine turns over, ECU should give injectors a pulse and trigger the ignition. If not ECU might be bad. You should check power and grounds going to ECU. There are usually multiple power and grounds going into ECU

Jan 06, 2014 | Cars & Trucks

1 Answer

1999 volkswagon jetta v6 cranks but wont start


I'm having a similar issue with my '97 Golf K2 with a 2.0 I checked the resistance to the crank sensor and it was almost 900ohms with the replacement one being 500 ohms. Changed it, didn't work.


Mine was running fine driving 70MPH on the highway and just shut off. Now it cranks, fuel pump runs and it seems to be getting fuel but still no spark. I have a coil/module on order and will try it tomorrow.


UPDATE

Replaced the coil. Coil sparks once when you first turn the key on, that's it. crank sensor has already been replaced yesterday.
Injectors seem to fire (I smell fuel if I crank it a while) but still no spark.
I have 12V to the coil and 12V when cranking.

I see tons of posts with this issue but no resolutions. Come on somebody has to have been here before....

UPDATE #2

I do NOT have an injector pulse or a pulsed signal to the coil. When I crank the car the oil pressure light blinks on and off (just noticed this not sure if it is relevant)

I do get a check engine light when I turn the key on and when cranking, thought this meant ECU was good?

Any other way to test the ECU?

Could the pick up in the distributor be bad? Doesn't the pick up signal the ECU to fire the coil and injectors, I thought the crank sensor was just a TDC reference point?

------------------------------------------------------------------------

Launch X431 Master

Mar 15, 2013 | Cars & Trucks

1 Answer

No injector pulse,new battry,fuel pump,crank sensor,check all grounds still no start on 1988 pontiac grand prix 2.8l do u think computer bad


my first thought based on what I could see in your description (you cannot see the entire post until you click on it) was the ECU-you have done a check of the fuel pressure, and checked the regulator for leaks, correct? I would try a junkyard ECU (25 to 50 dollars in most places) or on ebay. Also carefully examine the crank sensor connector, and the harness itself for damage-no crank sensor signal, no pulse. ECU's do not normally go bad, but it does happen.

Jun 28, 2011 | 1988 Pontiac Grand Prix

1 Answer

I have an Audi A4 2.5 V6 TDI. starts lovely when cold but when warm it doesn't start so easy. So far I've changed the cranking sensor, Glow plugs & ECT sensor . . . Any suggestions?


can be injectors leaking when parts is warm and expanded or temp sender not sending correct signals to ecu,so get injectors tested and replace temp sender.hope u succeed.

May 27, 2011 | Audi A4 Cars & Trucks

1 Answer

I need a honda car code , i can't turn on my radio


service manual.
Code Description Possible Cause
0 ECU / ECU signal No signal to ECU
1 Oxygen sensor circuit Oxygen sensor or circuit, ECU
2 Oxygen sensor circuit Oxygen sensor or circuit, ECU
3 MAP sensor circuit Map sensor circuit
4 CKP sensor / engine speed (RPM) Crank angle sensor or circuit, ECU
sensor
5 MAP sensor circuit MAP sensor or circuit, mechanical
problem
6 ECT sensor circuit ECT sensor or circuit, automatic
transaxle control unit
7 TPS / Angle Sensor TPS sensor or circuit, automatic
transaxle control unit
8 CKP sensor / engine speed (RPM) Crank angle sensor or circuit, ECU
sensor
9 CMP sensor CMP sensor or circuit
10 IAT sensor IAT sensor or circuit
11 Idle Mixture Adjuster Sensor Idle mixture adjuster sensor or
circuit
12 EGR system fault No EGR action, faulty EGR valve
13 BARO sensor circuit BARO sensor or circuit
14 Idle Air Control valve circuit / ECU Open or shorted out ignition signal
circuit / No signal to ECU
15 Ignition Output signal Open or shorted ignition output
signal circuit
16 Fuel Injector Circuit Open or shorted fuel injector
circuit
17 VSS circuit VSS sensor or circuit
18 Ignition Timing Adjuster Open or shorted signal circuit
19 A/T Lock-up control solenoid Open or shorted signal circuit,
Lock-up control solenoid lock-up solenoid
20 Electrical Load Detector / Sensor Electrical load detector or circuit
Honda/Acura
Fault Code Definitions (21 - 59)
Chapter 3 22
Code Description Possible Cause
21 Spool Solenoid Valve Open or shorted signal circuit,
spool solenoid valve
22 Valve Timing Electronic Oil Open or shorted signal circuit,
pressure switch valve timing oil pressure switch
23 Knock sensor circuit Knock sensor or circuit
30 AT / ECU communication signal A AT control unit, ECU
31 AT / ECU communication signal B AT control unit, ECU
35 Traction control / ECU / signal Traction control module, ECU
36 Traction control / ECU / signal Traction control module, ECU
41 Oxygen sensor heater - left side Oxygen sensor / heater or circuit
42 Oxygen sensor heater - right side Oxygen sensor / heater or circuit
43 Fuel Supply system - left side Oxygen sensor or circuit, fuel
system
44 Fuel Supply system - right side Oxygen sensor or circuit, fuel
system
45 Fuel metering - left side Injector control circuit, incorrect
fuel metering
46 Fuel metering - right side Injector control circuit, incorrect
fuel metering
48 Heated oxygen sensor Oxygen sensor or circuit
53 Right Knock Sensor Right knock sensor or circuit
54 CKP sensor 2 CKP sensor 2 or circuit
59 CMP sensor 2 CMP sensor 2 or circuit

Dec 28, 2010 | 1994 Honda Accord

2 Answers

R reg Megane Scenic non start


Hi

Well, no noid signal and no spark says to me that the crank sensor is at fault.

Does the check engine light come on when you turn on the igntion? If not then the ECU is not waking up.

Regards

Geordie

Jun 11, 2008 | Renault 181 Cars & Trucks

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

70 people viewed this question

Ask a Question

Usually answered in minutes!

Top Jeep Experts

yadayada
yadayada

Level 3 Expert

76164 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22156 Answers

Kevin Daniels

Level 3 Expert

1455 Answers

Are you a Jeep Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...