fuel no spark

[nomad327]

I've been looking all over the net and getting some insight to my problem. I will sum up what I have seen, and discussed elsewhere. This is not an emergency, the car is home and I have a spare vehicle.

I have an 89 MTX, well maintained. We bought the car new and it is unmodified and has always been perfect. It got a new Cam sensor about 9,000 miles ago, and about three thousand miles ago it had a new timing belt water pump crank position sensor and all the cam and crank oil seals, all Genuine Ford parts. It's Now about 101,000 miles. My wife drove it about two miles the other day, and shut it off and it would not restart. The car was towed to my house. I checked it over the fuel pump runs and there is fuel pressure at the Schrader valve. The camshafts are turning and it cranks strongly and seems to have good compression. There is no spark at any cylinder using an inductive timing light to check for spark. I had an autozone test of the DIS module as it is the only part not replaced recently and it passed five times. The tachometer needle moves a bit during cranking, about a needle width and the check engine light is on in the run position and while cranking. I tried jumping the starter solenoid with the key in run to reduce the likelihood it was the ignition switch, and it spun well, but did not make a spark with the key in run. The ground cables and battery cables seem to be sound, and the related connectors all seem tight. There is no indication of water pump leakage. I did the KOEO test and the relays and pumps cycled and I appeared to get several 11’s in a row, and then two 67’s which appear to be unrelated. I also checked the MAF and cam sensor connectors and alternately tried starting it with each disconnected, no change. Has anybody seen anything like this? I have been told the CPS is probably the culprit, but it is just barely broken in and was installed properly. I will replace it again if that seems like the problem. Thanks in advance, Ed.

 

[projectSHO89]

Ed, Welcome!

Several things come to mind:

1) Loss of power feed via fuse link "B". It supplies switch battery power to the voil, DIS module, CPS, CID sensor, and the IRCM. RED/LT GRN wire in all cases. Check it first.

2) Possible DIS module failure.

3) Possible CPS failure. Another forum member, rangerj, posted some pretty good diagnostic tests for the DIS and CPS. Perform an Advanced SEARCH using his username and SEARCH keywords "DIS Test" or "CPS Test" and see if you can dig them up.

Steve

 

[darylP]

fuse link B

Where would I find that link so I can check it on my car sence it sounds like it might be my problem also.

 

[projectSHO89]

Where would I find that link so I can check it on my car sence it sounds like it might be my problem also.

Did you check the indicated wire at the indiciated points to see if battery power was present or was missing?

Most (threeor so) of the fuse links are bolted to the battery terminal of the starter relay above the driver's side inner fenderwell. There is one link that runs directly off the battery positive post and is located within the first 12 inches of the wire connection from the battery.

Memory does not serve to separate their identities at this time.

Steve

 

[jedhead]

I replaced a working CPS when I did my 60K as preventative maintenance. 4 months later I had the same symtoms that you are experiencing. Murphy struck and my new CPS had failed.

Bob

 

[nomad327]

Thanks for your CPS failure insight jedhead. I have been using the advice in this and other threads and the great graphics of the wiring found here as well. I have the 89 factory manual, and the special 89 troubleshooting book, and I have gotten more help and insight from this site so far. I've been a while getting back to you, as it's slow work checking these things and the weather and early sunset have not been helping a lot either. I have a strong ground contact to the system, and have the fused power present at all components as well. I have started checking out the CPS and have been getting good readings with the exception of not getting any voltage to pin 33, the PIP PCM line. according to the Key On engine off table, I should see within a few volts of full battery voltage there and I'm not seeing any volts at all. I'm not out of things to check, ran out of daylight again. I'm just updating so you know it's all appreciated.

 

[nomad327]

I have finished going over my wiring and checking the remaining joints and I find the connections and wire pin to pin continuity is perfect. The computer ground is solid and the sixty pin connector on the eec does not look like it is a year old, let alone 16 years. No pins are pushed back in plugs and none are broken off. My fault is that there is no voltage provided from the computer at the 56 (PIP) pin to the crank position sensor 33 pin (I am told the Dark Blue wire should show near 12 volts with the connectors all made up and the key on). The test of the crank position sensor does not yield the hoped for volt spikes when cranking, but with no input voltage, that is not a surprise.

It looks to me as though the computer itself has to be bad. It must be able to do a good self test and give eleven codes and not know it is failing to provide PIP power. I am now going to locate another computer and try that unless someone sees an obvious point I might be missing? As before, thanks for the help and insight from this site.

 

[nomad327]

I submitted this and it disappeared after a bit, I am reposting so excuse any double post that may show up later.
I have finished going over my wiring and checking the remaining joints and I find the connections and wire pin to pin continuity is perfect. The computer ground is solid and the sixty pin connector on the eec does not look like it is a year old, let alone 16 years. No pins are pushed back in plugs and none are broken off. My fault is that there is no voltage provided from the computer at the 56 (PIP) pin to the crank position sensor 33 pin (I am told the Dark Blue wire should show near 12 volts with the connectors all made up and the key on). The test of the crank position sensor does not yield the hoped for volt spikes when cranking, but with no input voltage, that is not a surprise.

It looks to me as though the computer itself has to be bad. It must be able to do a good self test and give eleven codes and not know it is failing to provide PIP power. I am now going to locate another computer and try that unless someone sees an obvious point I might be missing? As before, thanks for the help and insight from this site.

 

[nomad327]

I have finished going over my wiring and checking the remaining joints and I find the connections and wire pin to pin continuity is perfect. The computer ground is solid and the sixty pin connector on the eec does not look like it is a year old, let alone 16 years. No pins are pushed back in plugs and none are broken off. My fault is that there is no voltage provided from the computer at the 56 (PIP) pin to the crank position sensor 33 pin (I am told the Dark Blue wire should show near 12 volts with the connectors all made up and the key on). The test of the crank position sensor does not yield the hoped for volt spikes when cranking, but with no input voltage, that is not a surprise.

It looks to me as though the computer itself has to be bad. It must be able to do a good self test and give eleven codes and not know it is failing to provide PIP power. I am now going to locate another computer and try that unless someone sees an obvious point I might be missing? As before, thanks for the help and insight from this site.

 

[projectSHO89]

The EEC does not provide any power to the CPS, that is provided via the R/LG wire.

The CPS has four wires:

1.) R/LG - Switched Vehicle power

2.) GY - PIP to DIS

3.) DB - PIP to EEC

3.) BK/O - IGN GND

The GY and DB wires should have the same signal on it at all times.

The "33" designator refers to the circuit number, not a specific connector pin.

I'm of the opinion that you have one of three possible faults:

1.) Defective CPS

2.) PIP input circuit in EEC internally shorted to ground

3.) Wiring harness fault, either open circuit between EEC pin 56 and the CPS DB wire or that signal line is shorted to chassis ground.

See post #20 in this thread rangerj's CPS Test if youhaven't found it already.

Steve

 

[nomad327]

Thanks,for such a thoughtful post. I know from other forums I frequent, where I am the expert on other model vehicles that it gets tiresome going over the same stuff over and over every few days for the latest newbie. I have a book going on an inch thick of different posts from various sources, mostly from here though. It includes the post you reference and It sort of got lost in the stack earlier on when I was looking at other components in the system. It is very timely now, and I appreciate you taking the time to look it up and reference it for me here. My conclusions are the same as yours with the exception I thought I was to see 12 V at the crank sensor through the blue wire. I have tested the pip wire and have continuity with no ground, I have another computer in hand from my parts car, but will recheck the items you mention first.

 

[nomad327]

I wanted to close the thread, It was the crank position sensor. It started right up with a new sensor. I just hated the idea of it being the sensor, because I just took out a good one for preventative maintenance and barely got a year out of the replacement. I lost near a month checking out everything else, but was satisfied at the end with it being the sensor. I also know the ignition system a lot better now as a result. As the genuine Ford part failed so quick, I bought one aftermarket this time, figure it can't do any worse. I really appreciate all the input guys, maybe this will help someone else out in the future.

 

[somedude_001]

is there not a 1 year parts warranty on that?

 

[nomad327]

I believe there is a one year warranty, but I bought the old one a month or so before I did the timing belt service, and I did the work myself. It's unlikely ford will pick it up at that rate, but it was a nice thought.