View Full Version : No injector pulse, Help please!


K_Hairston
03/21/09, 09:46 AM
Ok, I have spark, 41# fuel pressure and no injector pulse. I am running a RJM 95 351 with bc adaptor and mustang 5.0 upper. The first attemp to fire the engine. It will run on supplied fuel throught the intake. I thought the same signal from the distributor that went to the computer to fire the coil also sent the signal to the ecm to fire ground to the individual injector. I have batt voltage at one side of the injector and m not getting the ground pulse from the ECM. Where do I start?

bax
03/21/09, 10:06 AM
Sounds like you ecm is not getting the engine RPM signal. No signal no injector fire. Check your dist wiring harness again.

K_Hairston
03/21/09, 10:55 AM
I have a breakout box, but don't know what I am supposed to see comong on PIP 56? Also, I have batt voltage on one side of all injectors with key on, should this be 5V???

Viperwolf1
03/21/09, 12:08 PM
I have a breakout box, but don't know what I am supposed to see comong on PIP 56? Also, I have batt voltage on one side of all injectors with key on, should this be 5V???

This page shows what the PIP signal looks like. http://fordfuelinjection.com/?p=25 You could attach a tachometer to this wire to test the PIP signal coming from the distributor. You probably wouldn't see a good steady rpm during cranking but should see the pulses. An analog voltmeter would work great too.

The injectors operate on 12v.

K_Hairston
03/21/09, 08:41 PM
I have some small movement on the tach. Almost none. Is there a better way to know whether or not the PIP is doing its job?

Viperwolf1
03/21/09, 08:48 PM
I have some small movement on the tach. Almost none. Is there a better way to know whether or not the PIP is doing its job?

An oscilloscope would work. You could also measure the PIP coil resistance but you'd need to pull the TFI module off first. 600-1300 ohms is good.

Edit: Nevermind the coil resistance test. This is for older non-Hall effect TFI distributors.

K_Hairston
03/22/09, 06:48 AM
I pulled the distributor back out and removed theTFI. I am driving across town to another AZ to get a new distributor as soon as AZ opens.
1) Is there a wat to test the distributor off the engine at the parts store?

2) If not I can ohm it out but what two points do I connect my multimeter to?

3) Third pin on the right of the stator is the PIP out signal, and where else?

Viperwolf1
03/22/09, 12:21 PM
I pulled the distributor back out and removed theTFI. I am driving across town to another AZ to get a new distributor as soon as AZ opens.
1) Is there a wat to test the distributor off the engine at the parts store?

2) If not I can ohm it out but what two points do I connect my multimeter to?

3) Third pin on the right of the stator is the PIP out signal, and where else?

Here are some module tests.

K_Hairston
03/22/09, 02:32 PM
In the last 12 hours:
(1) NEW ECM
(2) new TFI Modules, (1) wells, (1) BWD
(3) Reman distributors

Still No injector pulse. All the powers and grounds listed on FordFuelInjection.com are evident, only the codes that are to be expected were revealed with the KOEO test, Fuel Pressure is 40#, 12V on one side of each injector no ground pulse to any injector. I do not have a good grasp of what voltages should be at the TFI during KO or when starting although I have seen some info on this.

Could anyone clarify what you are supposed to have at the TFI, while connected to the harness during KO and start. Thanks.
Keith

Viperwolf1
03/22/09, 03:27 PM
There is one instance when the ECM would kill injector pulses. That is when the engine is flooded and you have your foot all the way down on the accelerator. I imagine you don't have your foot down but it's the TPS's job to measure this. Check the TPS output voltage.

K_Hairston
03/22/09, 03:50 PM
What should the TPS output voltage be? It uses 5V ref, right? Also, should I disconnect the TPS to try it?

bax
03/22/09, 04:24 PM
It should still run with the TPS disconnected. Give it a try.

Viperwolf1
03/22/09, 04:50 PM
What should the TPS output voltage be? It uses 5V ref, right? Also, should I disconnect the TPS to try it?

Yes 5v ref. At idle it should be just under 1v output. You would have to leave it connected to check voltage but Bax is correct, it should run with it disconnected.

K_Hairston
03/22/09, 05:02 PM
I checked the three wires at TPS:
Blk: grd
Grn: .961V
Org: 5V

Unplugged and tested for injector pulse---Nothing.

Viperwolf1
03/22/09, 05:09 PM
I hate to say it but it sounds like either a harness wiring problem or a bad ECM. If you have spark the PIP is working. Sorry I didn't catch that earlier.

K_Hairston
03/22/09, 05:14 PM
I thought so too so I got a BRAND new Motorcraft ECM out of a New motorcraft box and tried it, no change. I checked continuity between the PIP harness at the distributor and at the ecm- good- 3.9ohms

It runs with starting fluid, but doesn't even begin to rty and start without it. I pulled the No.1 spark plug and it is dry, but smells of Ether from my starting fluid.

I am out of ideas.....

Viperwolf1
03/22/09, 05:18 PM
look at the ECM connector #47. This is where the TPS return voltage goes. It may have been mis-pinned with a Vref wire.

K_Hairston
03/22/09, 05:24 PM
I thought ECM as well, so I tried a brand new ECM out of a Motorcraft box- no change. My original thoughts were that if the ECM is reading the PIP and not sending out the injector pulses. But that would be an ECM issue, not a hraness. If it were the harness I would expect to get some cylinders firing, but maybe not all. So I checked continuity between the PIP coming out of the TFI and the connector at the ECM-2.9ohms.

If there is a problem with the harness, how can I check it? I am out of ideas.

K_Hairston
03/22/09, 05:27 PM
Does RJM offer any support?

bronco-billy-66
03/22/09, 08:29 PM
Bump TTT... Any updates

Viperwolf1
03/22/09, 08:48 PM
Does RJM offer any support?

You could try to PM/email/call Ryan. Before you do make sure to go through his install directions again to make sure you didn't miss anything.

bax
03/22/09, 09:27 PM
Do you have power to the ECM? I know it sounds stupid but worth a check

K_Hairston
03/23/09, 02:08 PM
To review, I installed a 95 351W 5.8L engine in my 74 Bronco , NP435. I purchased a RJM Harness for the 89-93 Mustang 5.0L in October and installed it in December. The engine is a 38,000 mile used engine from a rolled f-250. I also added a 3G alternator and used the 3G Harness that was ordered with the RJM main engine harness.

I followed the directions in the installation instructions and found this to be a simple process and was impressed with the lengths being so clean, etc. The IAC plug was too short and had to be lengthened to accommodate for the BC Throttle cable and 1” BC adapter between the upper and lower intake manifolds, no fault there. The only thing left to do is the HEGO sensor bungs being welded into the exhaust pipes. I plugged the sensors in to the harness and have them tied up to the firewall.

Upon initial start-up I set the distributor at 10’ BTDC and left the spout connector hooked up to try and start. Turned key on and off until the fuel system was primed (4) times. Fuel pressure was 85# pre regulator and 41# after regulator. Engine spun over when in start position, but would not start (or even try to start). I connected and inline spark tester and had spark. I checked fuel pressure again, 40#, no significant bleed down after 60 sec. Now we tested for injector pulse while engine spinning over- Nothing. I removed the number one cylinder pigtail from the injector and measured batt. voltage with key on (the red wire). The other wire was tan and I connected it to my test light with the alligator clip on Batt +, while attempting to start the engine. No flash, although there is a very very faint glow.

This is where I connect my break-out box. I test for batt + and grounds where appropriate using the Fordfuelinjection.com website link. This is with key on. I then ran a KOEO test for codes and got exactly what was described at Fordfuelinjection.com.

I posted to CB.com and someone said, “There is one instance when the ECM would kill injector pulses. That is when the engine is flooded and you have your foot all the way down on the accelerator. I imagine you don't have your foot down but it's the TPS's job to measure this. Check the TPS output voltage.” So I did I checked the three wires at TPS:
Blk: grd
Grn: .961V
Org: 5V
Also, unplugged and tested for injector pulse---Nothing.

Viperwolf on CB thought it might be a bad ECM (A9). The ECM was used and not off a running vehicle so I tried a brand new ECM out of a Motorcraft box- no change. My original thoughts were that if the ECM is reading the PIP and not sending out the injector pulses. But that would be an ECM issue, not a harness. If it were the harness I would expect to get some cylinders firing, but maybe not all. So I checked continuity between the PIP coming out of the TFI and the connector at the ECM- 2.9ohms. I took two TFIs to oreilly to test and both were ok. At a loss on Sunday, I installed another Reman Cardone Distributor for a 90 F-250 5.8L with the dist mounted TFI, also installed a new TFI. No change. Now that I have replaced all my junkyard parts with new I am back to diagnostics.
I gave it a squirt of staring fluid and it starts right up and dies as soon as the supplied fuel runs out. PLEASE HELP! (832)282-8299 Keith
Questions:
1) I do not have a good grasp of what voltages should be at the TFI during KO or when starting although I have seen some info on this. Could anyone clarify what you are supposed to have at the TFI, with KO and start.
2) I am suspect of the PIP signal (56) from the stator through the TFI because I do not know how to measure it, even with the breakout box.
3) I have access to an Oscilloscope, but have never used on and don‘t know what to test. Is this necessary?
4) If there is a problem with the harness, how can I check it? I am out of ideas.

K_Hairston
03/28/09, 08:00 AM
:cry: ALL,
I have spent all morning checking grounds and resistance. I am almost convinced that this is my problem.
Grounds:
1) I have a ground strap from the primary battery to the engine. 10.8 ohms from the engine to neg batt post, ok???
2) and from the engine to the body.
3) The ECM ground is connecter to a bolt on the back side of the lower intake. 10.8 ohms from the ecm ground wire at the back of intake to neg
batt post
4) the resistance from the ECM at the main haness connector to neg batt post is 41 ohms
5) the resistance from the relays(all 4) to the neg batt post is 68 ohms.

This is BAD, right????

Pedestrian
03/28/09, 09:23 AM
I'm no expert, but those readings sound way off. I would expect less than 4 ohms on any ground.
I'm still running carb so I can't really check for you.
Hope you figure it out, I have been watching this thread with great interest.

Viperwolf1
03/28/09, 09:29 AM
:cry: ALL,
I have spent all morning checking grounds and resistance. I am almost convinced that this is my problem.
Grounds:
1) I have a ground strap from the primary battery to the engine. 10.8 ohms from the engine to neg batt post, ok???
2) and from the engine to the body.
3) The ECM ground is connecter to a bolt on the back side of the lower intake. 10.8 ohms from the ecm ground wire at the back of intake to neg
batt post
4) the resistance from the ECM at the main haness connector to neg batt post is 41 ohms
5) the resistance from the relays(all 4) to the neg batt post is 68 ohms.

This is BAD, right????

Yes. Way too much resistance. Make sure battery is grounded to the engine block well and you have a good ground to the body. A good frame ground is also needed if you have fuel pumps grounded there.

wpaeb
03/28/09, 10:22 AM
On your relay grounds. The ECM switches the grounds to activate them. 10.8 is higher than I'd expect but should not stop it. With a voltage meter check from the main ecm connector ground pins to the neg post. This should be less than 1 volt. If there is spark the TFI is working. Some one else suggested testing the TPS pin at the ecm. At idle it should read .96. If it where the 5v ref the ecm would run the flooded strategy.

I do not under stand your 80psi before reg and 40 after. Before the reg should be 40 and after almost 0. In stock form.

Viperwolf1
03/28/09, 10:33 AM
10.8 ohms from engine to battery is about 10.5 ohms too much. The injectors only have 15 ohms of resistance so you'd be losing 40% of the voltage right off the bat.

K_Hairston
03/28/09, 09:32 PM
Added a ground to the body and improved other grounds, corrected fuel problem and got it going. Thanks to all!

Pedestrian
03/29/09, 12:34 AM
Thanks for the update, great to see another one up and running.

fortzav
08/16/09, 10:45 PM
I'm having the same problem, how many grounds are we talking about? One by the A9L, ORANGE for the O2 sensors, and the main ground to the engine. Are there more?