89 NOT starting Replaced CPS TPS....

[serge]

againstherwill:

I am also dealing with an '89 XJ here, although it starts but will not run. Maybe I could give you a couple of pointers
1) The non-technical way of knowing if injectors are working -- take a smell test -- I definately smell fresh fuel in the engine compartment after cranking a couple of times and preventing a spark.
2) According to an '88 FSM (available on the net with some searching), besides the usual usual suspects, an open CTS Sensor will prevent the start. I've confirmed this by unplugging mine and not getting a start. Mine reads around 7K Oms across its terminals with 45 degrees outside.

 

[againstherwill]

See this is where this sh*t rget to you after three days of replacing. Anyway. I when I took the old plugs out after trying to get it to start they were black and wet with Gas. Meaning Gas getting to cylinders. FF to Today. New Plugs and New fuel pressure now gas in cylinders. So that is why I am thinking electrical. I will check the cps but it just seems weird that it would be that if I just replaced it?

 

[serge]

Power Latch AKA B+ Latch AKA ASD (Auto-ShutDown) Relay is located in the relay center on passenger side. It is the one with pink wires going to it. Testing is the same is other relays, or by swapping around. If malfunctioning, it supposedly will cutoff the fuel delivery.

Here is the test with a voltmeter:
1. A relay in the de-energized position should have continuity between terminals 30 and 87A.
2. With an ohmmeter, measure the resistance between terminals 85 and 86. The ohmmeter should indicate a resistance value of 75 +/- 5 ohms for resistor relays, and 86 +/- 5 ohms for diode relays

 

[langer1]

Langer you never replied to what a power latch relay is? What is it and where is it at can't find anywhere?

Supplies power to the injectors.

 

[serge]

Hmm, you've posted earlier that you've had spark at the plugs and just confirmed that there is fuel in the cylinders. Physics says you must have ignition going on. Unless the fuel is bad or the third (often-assumed-to-be-there) component -- air -- is missing. Did you open up the throttle body and check its cavities for deposits? Also, take out the IAC (next to TPS) and see if its pintle is clean and is in retracted position.

 

[againstherwill]

Langer thanks That is helpful. All relays checked good. you the man!

CTS shouldn't this be located on the front of the housing where the upper hose and and overfull run to? if yes I ain't got one. If no where can I look?

 

[serge]

CTS shouldn't this be located on the front of the housing where the upper hose and and overfull run to? if yes I ain't got one. If no where can I look?

CTS is located on the right side of the engine (if you are laying down underneath it legs first). Its connector is right next to the oxygen sensor's connector.

 

[8Mud]

Langer thanks That is helpful. All relays checked good. you the man!

CTS shouldn't this be located on the front of the housing where the upper hose and and overfull run to? if yes I ain't got one. If no where can I look?

Lower left of the block front, I'm guessing CTS is coolant temp sensor :laugh3:
Just so we don't get confused, in auto 101 they told me all the lefts and rights in a car are as seen while sitting in the drivers seat.

 

[serge]

Great website for you, from my archives here: has tests, pics and testing procedures for all important Renix sensors:
http://www.lunghd.com/Tech_Articles/Engine/Basic_Sensors_Diagnostics.htm

 

[langer1]

The other one that will give a no start at times is the CKP or Cam Posistion sensor.

 

[8Mud]

againstherwill:

According to an '88 FSM (available on the net with some searching), besides the usual usual suspects, an open CTS Sensor will prevent the start. I've confirmed this by unplugging mine and not getting a start. Mine reads around 7K Oms across its terminals with 45 degrees outside.

Did you figure out whether it caused no spark, no fuel or both?

 

[againstherwill]

I tested the CTS and Got appropriate 7000. So I guess that I am ordering a new Distributor. Its the only thing left other then the computer.

 

[8Mud]

Do a cam position sensor test, no big deal.
Doubtful it's the problem anyway. Buying parts on a guess, gets real expensive real fast.
I always work on the assumption the problems in the wiring, test that first, then buy a sensor. I've actually only had to buy few, in like 17-18 years.
I also usually work on the assumption the answer is probably the simplest. I work from the basic to the obscure.
Two things you have to have when troubleshooting is a plan and Patience.
Go back to the basics, plugs firing, injectors firing.
Injectors are 12 volts, back pining a injector in wire, with a volt meter and cranking it will probably tell you if they are cycling or not. I usually use a stethoscope and listen to an injector.
Obscure, had one XJ that refused to keep running, It would start and then crap out after thirty seconds or so. It had been sitting for most of a year, just on a hunch I blew air through the fuel lines, with the line disconnected from the fuel rail. A glob of scum colored snot shot out of the end. Stuff like that will drive you nuts.
The spark should be sharp and almost totally blue and make a crack sound when it fires. If it's yellow and splashes, it may or may not fire the fuel air mix. It may ignite ether, but may not ignite gas, before the ends of the plugs get fuel fouled.

 

[againstherwill]

Mud Thanx

Basics are :

Spark: after replacing the distributor cap and plugs the The spark is sharp and blue prior to replacement spark was yellow and wavish. The CPS was burned almost through. The old TPS had only 1.4 on the out. Map is good not replacing.

Fuel: The fuel rail has fuel under pressure at the check valve. Prior to fuel pump and fuel filter no pressure. Fuel pressure regulator had gas in the vacuum line when I checked it.

Air: no leaks in intake system

I will definitely try blowing out the lines. Seems only resonable that there could gunk in there.

However with all sensors replaced that were bad and the rest testing okay (unless its the lines) it seems like the last thing to check would be the Camposition senor in the distributor. so with that being the case I would rather KNOW it is good read NEW than test it and think it is. Besides it is the last thing it could be with all testing and replacement. If that ain't it then I know its a wiring issue and can start pulling wires.

Thank you all very much for the help and the suggestions everyone here has been extremely helpful. This board is the best and has the most knowledgeable help people.

 

[againstherwill]

BTT.

Update.
Blew out the gas lines. Was some gunk in there. Cam position sensor in Distributor was bad. Replaced Distributor making sure at TDC. Still no start.
Because the only thing it can be at this point is electrical. I splice the NEW CPS Wires and with the ignition to on position and the engine not running (at this point wondering if it every will) I get nothing, zero, ziltch,nada on the meter.

Anyone know how I can trace this back to the ECM? Willing to try just need to know where to look. I saw the digram on rangers post about a similar issue. Anywhere else I should check before I call the stealership to fix it?

Thanx topher

 

[old_man]

Rather than spend a ton for parts at this point, you need to check and verify a few things. First you need to make sure you really have fuel pressure. See if you can borrow/rent one. Check the local chapter if anybody has one.

Borrow/rent a set of noid lights. These go in series with the injector electrical drive. They will tell you if the injectors are being fired. In other words, if you have fuel pressure and injector drive, but no fuel, then the injectors are clogged. This by the way is my best guess.

If you haven't drained the tank, you need to do that first anyway. After putting in clean gas, disco the output from the fuel rail and run it into a bucket, kick on the fuel pump and flush the lines for about a half gallon.

Your test of shooting fuel in through the throttle body was good troubleshooting technique. It told you that the problem was a lack of fuel. Now your task is to figure out what is causing the problem. Rather than replace the injectors, I would pull them and take them to a good mechanic that has an injector cleaning system. If you do the pulling and talk to the mechanic, you should be able to get it done fairly cheap. Anyway, having them cleaned is not a bad thing to do, period. Since they are not flowing, you can't use BG44K, which I would recommend if it were simply running real crappy.

If you decide to get new injectors, if you can't find them reasonably priced over there, get in touch and I will see what I can find and can arrange to ship them to you.

 

[8Mud]

At one time you had fuel and spark or I misunderstood. There was a sharp blue spark and the plugs were wet with fuel. It should have gone pop, at least.
One thing that will cause it not to go pop, is water in the fuel. The wet plugs are partially wet with fuel and partially wet with water. The spark takes the wrong path to ground and doesn't get hot enough to fire the fuel.
You said you could get it running, with starter spray.
All of the sensors you have found bad are unusual to say the least. Test the voltage *in* for your MAP. Should be around 5 volts. This is just to make sure you don't have 12 volts in the sensor voltage supply circuit somewhere (which is very bad).
The fuel pump relay supplies voltage for the pump, when the vehicle is running (or for a few seconds when the key is first turned to run). During start the fuel pump relay feed for the fuel pump and the ballast resistor is bypassed. You really have to make sure you are getting pressure with the key in run and during start both.

Do what Old_Man suggested. If the noid lights aren't firing.

Then test the fuel injector power supply into the ECU (actually two feeds/two wires). The power leads (orange wires I think) to the ECU, go to pins C-11 and D-10 and originate at the same place, the 87 pin at the fuel pump relay. The 30 is power *in* to the fuel pump relay (should be always hot from a fusible link) and power out is 87. The power out (87 pin) from the relay goes to the fuel pump, the injector feed wires to the ECU, the purge solenoid for the charcoal canister and the power latch relay, through a *splice*. There are many possibilities for low voltage and/or resistance in this circuit. An ohm test from the C-11 pin and D-10 at the ECM connector and the 87 pin at the fuel pump relay (with the relay removed) should tell you if there is an open circuit or highly resistive wiring (bad splice).
Whenever you get done with this, you'll end up a Renix wiring expert.
The 30 pin for the fuel pump relay is power in, the 87 pin power out. The relay is closed (making contact between the 87 and 30) by the 86 and 85 pins on the relay. The 86 pin has power with the key on and the 85 pin is *grounded* through the ECU to control the fuel pump relay opening and closing. The 85 and 86 pins are actually wired backwards on some Renix XJ´s.
Taking it to the dealer may or may not be a solution, my XJ is one the dealer gave up on and was about to junk. Though I'm not knocking the dealer, it took me a looong time to find the trouble.