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jdsgallops
11-07-2013, 02:15 PM
About a year and a half ago I was trying to merge onto the interstate when my 90sc just died. No attempt at a restart would work. Towed it home and let it sit while I dealt with my divorce. Over the last 6 months or so I have been chasing the problem. Shift light stayed on so in went a new cranki sensor. No luck. Found the harmonic balancer wobble and replaced with a SFI BHJ. No luck. Pulled the engine and much to my surprise found a 2 piece crank. After procuring an entire new motor and using the best parts between the two I finally have the car back together and am trying to start it. Starter turns over but no fire. I have verified fuel at the rail. Cam sensor was installed with #1 piston at TDC and shaft aligned with mark. My next step is to verify this along with testing for spark. Shift light goes off when cranking. With the DIS system firing 2 cylinders at a time I would expect to hear a cough once in a while though if timing was just off. Which leads me to believe I have no spark, which I will verify when I have time. If I do indeed have no spark would I start to look at the DIS module. I have a spare here, assumably good from the 2nd engine I purchased. All wiring has been double checked from engine reinstall and all is connected.

KMT
11-07-2013, 02:26 PM
Have you pulled the codes, yet?

David Neibert
11-07-2013, 03:48 PM
Cam sensor was installed with #1 piston at TDC and shaft aligned with mark.

It's supposed to be installed with #1 cylinder (compression stroke) 26 degrees after top dead center. If you unplug the sensor the computer will guess at the correct sequence (1 in 3 chance).

David

archerman0531
11-07-2013, 04:39 PM
I would also check to make sure you have injector pulse. That is if you don't smell gas from the cranking of the engine.

S_Mazza
11-07-2013, 05:34 PM
Sure that the EEC ground next to the battery is fully connected?

Does the radiator fan come on when the key is turned to "On"?

Did you check the actual pressure at the fuel rail test port, before and during crank?

aroot1
11-07-2013, 07:41 PM
Sure that the EEC ground next to the battery is fully connected?

Does the radiator fan come on when the key is turned to "On"?

Did you check the actual pressure at the fuel rail test port, before and during crank?

X2.

That ground burned me for 2 days of trouble shooting and swapping known good parts on the last one I restorected from the dead. Had fuel at the rail, but no pressure, fuel pump was not cycling, fan on w/key, and no inj pulse.

Adam

jdsgallops
11-08-2013, 01:14 AM
Dave all the info I found stated to install at top dead center and then set to mark, assuming mark was made prior to disassembly. Since the mark on the shaft was there prior to my ownership I am assuming that is what the mark is for. With it set to the mark it is pointed in the correct direction. This is why I need to reverify.

As far as ground goes I am pretty sure that I have all of them reconnected. The one by the battery should not have been disconnected to get the engine out. As it stands now the battery is grounded to the drivers side motor mount and there is a grounding strap from the passenger motor mount to the frame rail under the coolant overflow tank. I am going to agree with you guys though as I do not smell fuel after cranking, I seem to have no spark, and my tweecer is not able to talk to the computer. All familiar as I needed to add another ground strap from the engine to firewall on my Mustang.

I should have added in my original post the ignition switch seems to be bad. Car will crank fine for 2 or 3 revolutions and then "kicks back". Using the remote starter on the solenoid the car turns over fine. Looks like I need to replace it and verify my grounds before I go any further. Thanks for the suggestions!

archerman0531
11-08-2013, 01:18 AM
Smell of no fuel could mean injectors aren't firing. EEC controls injectors. Not being able to access the computer sounds like a computer or reader problem.

But just with those two it sounds as tho your EEC isn't working.

90tbird4.7l
11-08-2013, 05:30 AM
89 and 90 SC's dont have an EEC test connection, they are blackbox only (unless you have a Quarterhorse or some other similar chip). Here is the test procedure for the 89-90 SC DIS. http://mnharms.com/tutorials/disnostart/

archerman0531
11-08-2013, 09:57 AM
89 and 90 SC's dont have an EEC test connection, they are blackbox only (unless you have a Quarterhorse or some other similar chip). Here is the test procedure for the 89-90 SC DIS. http://mnharms.com/tutorials/disnostart/


I have a 90 cougar XR7. There is a port in the engine bay that is labeled "EEC test connector". You plug in the code reader there. You do the KOEO and KOER test thru there

Not being able to retrieve codes indicates that either 1) you have faulty wiring. 2) loss of power to the EEC. 3) bad EEC ground. 4) bad EEC.

BirdofPrey97
11-08-2013, 10:08 AM
The local parts store can test a DIS.

S_Mazza
11-08-2013, 12:16 PM
As it stands now the battery is grounded to the drivers side motor mount and there is a grounding strap from the passenger motor mount to the frame rail under the coolant overflow tank.

The negative battery cable (at least on all all the years I am familiar with) also has a small gauge wire (10 or 12) that connects to a ground lug on the radiator support. Is that installed? From there, it goes down, through a barrel connector, and then across the car and to the EEC. That is the critical ground connection for the EEC. I would trace that or get long multimeter leads and test continuity from the EEC harness connector to that barrel connector.

David Neibert
11-08-2013, 12:28 PM
Dave all the info I found stated to install at top dead center and then set to mark, assuming mark was made prior to disassembly. Since the mark on the shaft was there prior to my ownership I am assuming that is what the mark is for. With it set to the mark it is pointed in the correct direction. This is why I need to reverify.

I'm not sure if you are talking about a mark on the sensor stalk or on the balancer. Doesn't matter because if you are setting it up to top dead center and then installing the stalk it's not going to work. Follow the instructions in this post for properly installing the cam sensor stalk.

http://www.sccoa.com/forums/showpost.php?p=365956&postcount=2

David

jdsgallops
11-08-2013, 12:52 PM
The negative battery cable (at least on all all the years I am familiar with) also has a small gauge wire (10 or 12) that connects to a ground lug on the radiator support. Is that installed? From there, it goes down, through a barrel connector, and then across the car and to the EEC. That is the critical ground connection for the EEC. I would trace that or get long multimeter leads and test continuity from the EEC harness connector to that barrel connector.

A quick look when I got home from work last night. The ground you are talking about has double wires coming out of it. One is the wire going across the engine bay towards the EEC. The other is missing. I have two ground leads unused on the battery cable. Sounds like I need to run a ground wire here. Simple fix hopefully.

David thanks for the link. Once the other issues are resolved I will address this issue as it has been my biggest concern in getting the car running again.

S_Mazza
11-08-2013, 01:08 PM
A quick look when I got home from work last night. The ground you are talking about has double wires coming out of it. One is the wire going across the engine bay towards the EEC. The other is missing. I have two ground leads unused on the battery cable. Sounds like I need to run a ground wire here. Simple fix hopefully.

David thanks for the link. Once the other issues are resolved I will address this issue as it has been my biggest concern in getting the car running again.

I think you will be pleasantly surprised once you add a ground there. :)

By the way, if the cam sensor is out of position, you can unplug it and run without it temporarily, though starting will probably take a few tries.

90tbird4.7l
11-09-2013, 08:10 AM
I have a 90 cougar XR7. There is a port in the engine bay that is labeled "EEC test connector".

My 90 SC doesnt have a test connector for the EEC, just the ABS and ARC

KMT
11-09-2013, 10:15 AM
I've never seen an SC that didn't have an EEC/VIP Self-Test connector - for a 1990: engine bay, passenger side, back against the firewall where the fender turns down. Grey connector and pigtail.

See location 2-C, Figure 2, on the first page (218) in the Component Locator. (http://www.sccoa.com/forums/attachment.php?attachmentid=12628&d=1114666159)

This image shows how to set up to manually check codes/count flashes instead of just plugging in a reader.

http://www.thorssell.net/hbook/images/4hup96.gif

90tbird4.7l
11-09-2013, 07:25 PM
Sorry to highjack this thread.
Here is a pic of the connectors i have, neither have the self test input
pigtail.

S_Mazza
11-10-2013, 12:29 AM
Sorry to highjack this thread.
Here is a pic of the connectors i have, neither have the self test input
pigtail.

The EEC plug should have a cover just like the ARC cover, only colored black. The pigtail is supposed to tuck into that cover, but it is a separate wire. The self test input pigtail could have been accidentally severed somehow. I would take a hard look behind the wheel well.

jdsgallops
11-10-2013, 01:07 AM
Put a quick ground from the radiator support to the battery. I can hear the fuel pump cycling now but still no start. Turning over very hard. I have the trickle charger on the battery and it showed full charge. After 3 tries I checked the battery with the large charger it it was under 50%. The ignition switch seems to be robbing power and not letting it turn over well. Until it is replaced I am at a stand still it seems. I still can not get the Tweecer to communicate with the computer. I am hoping that I do not have the same issue I did on my mustang and because of the lack of ground for the computer, the computer became the ground blowing it out. Unfortunately the bolt that holds the wiring harness to the computer seems to be stripped out. Gotta love these cars. Every time you think you got it it throws another curve ball to keep you guessing.................

90tbird4.7l
11-11-2013, 08:20 AM
The EEC plug should have a cover just like the ARC cover, only colored black. The pigtail is supposed to tuck into that cover, but it is a separate wire. The self test input pigtail could have been accidentally severed somehow. I would take a hard look behind the wheel well.

I looked all over these are the only 2 test connections on the car. The ABS connector had a black clover but I misplaced it when i was trying to figure out why the ABS wasnt working. Turned out the fuse was blown.

David Neibert
11-11-2013, 12:36 PM
Put a quick ground from the radiator support to the battery. I can hear the fuel pump cycling now but still no start. Turning over very hard. I have the trickle charger on the battery and it showed full charge. After 3 tries I checked the battery with the large charger it it was under 50%. The ignition switch seems to be robbing power and not letting it turn over well. Until it is replaced I am at a stand still it seems. I still can not get the Tweecer to communicate with the computer. I am hoping that I do not have the same issue I did on my mustang and because of the lack of ground for the computer, the computer became the ground blowing it out. Unfortunately the bolt that holds the wiring harness to the computer seems to be stripped out. Gotta love these cars. Every time you think you got it it throws another curve ball to keep you guessing.................

Did you re-install the cam sensor stalk using the directions I provided ? Asking because it's very likely, that could be what is keeping it from starting.

David

S_Mazza
11-11-2013, 12:55 PM
Put a quick ground from the radiator support to the battery. I can hear the fuel pump cycling now but still no start. Turning over very hard. I have the trickle charger on the battery and it showed full charge. After 3 tries I checked the battery with the large charger it it was under 50%. The ignition switch seems to be robbing power and not letting it turn over well. Until it is replaced I am at a stand still it seems. I still can not get the Tweecer to communicate with the computer. I am hoping that I do not have the same issue I did on my mustang and because of the lack of ground for the computer, the computer became the ground blowing it out. Unfortunately the bolt that holds the wiring harness to the computer seems to be stripped out. Gotta love these cars. Every time you think you got it it throws another curve ball to keep you guessing.................

Well, that's progress.

As for the ignition switch, if it's bad, it will generally show when you open up the column covers. The plastic part of the switch will be separating from the metal part, and will be wobbly. Be careful because it's always hot with large gauge wires.

Another thing to check is the connections at the starter relay and at the starter itself. They can very easily get corrosion that makes the electrical system work too hard to run the starter.

Have you re-checked for spark after adding the ground? I wouldn't be surprised if the bad harmonic damper crashed into the crank sensor and ruined it.

jdsgallops
11-12-2013, 10:46 AM
David I have not had time to get that deep into diagnosing. A 50 hour work week and being a single father with 50% custody of a 2 year old doesn't leave much time to work on the car. I will address that issue when I am satisfied that it is not a grounding/power to the computer, time and weather allow. Knowing it is going to be 60 in a couple days doesn't give me much motivation to stand in the garage when it is only 40 out with 30mph wind gusts!

S. Mazza the engine was just reinstalled so I can rule the starter connection out. It looked perfect. I need to double check but am pretty sure the shift light was off during cranking which would indicate a signal from the crank sensor if I understand it correctly. I have 4 crank sensors here I know at least one of them is good. Next step is to check to igintion switch for the signs you indicated. There were signs that it was an issue before the car died and this project started so I will drop the column and pull the covers to verify it's condition. The cars spins over freely with the remote starter but cranks very slowly with the key to the point of acting like it has a drained battery. Something is soaking up battery power while cranking. Ignition switch from what I have read seems like a good place to start in looking for the culprit.

Thanks again everyone for being a "fresh set of eyes".in helping me solve this issue.

David Neibert
11-12-2013, 01:15 PM
David I have not had time to get that deep into diagnosing. A 50 hour work week and being a single father with 50% custody of a 2 year old doesn't leave much time to work on the car. I will address that issue when I am satisfied that it is not a grounding/power to the computer, time and weather allow. Knowing it is going to be 60 in a couple days doesn't give me much motivation to stand in the garage when it is only 40 out with 30mph wind gusts!

Just hate to see you wasting time checking a bunch of other stuff, when you have already identified something that was done wrong when reassembling the motor.

Here is an easy test...unplug the sensor and let the computer guess at the correct injector firing sequence. It has a 1 in 3 chance of getting it right, so the most it will take is 3 tries (10 seconds of cranking each time) to start the motor, with sensor unplugged.

David

S_Mazza
11-12-2013, 03:27 PM
David I have not had time to get that deep into diagnosing. A 50 hour work week and being a single father with 50% custody of a 2 year old doesn't leave much time to work on the car.

Hard to believe, but hanging out with a toddler is much more rewarding than fixing a greasy old car. Sure is a lot more work, though! :rolleyes:


Next step is to check to igintion switch for the signs you indicated. There were signs that it was an issue before the car died and this project started so I will drop the column and pull the covers to verify it's condition.

You don't even need to drop the column to remove the black plastic covers. Just 3 screws from the bottom, as far as I know. Then tilt the wheel as needed to remove each piece.

jdsgallops
11-12-2013, 07:09 PM
O


Here is an easy test...unplug the sensor and let the computer guess at the correct injector firing sequence. It has a 1 in 3 chance of getting it right, so the most it will take is 3 tries (10 seconds of cranking each time) to start the motor, with sensor unplugged.

David

I wasn't thinking of it this way but thanks for making that point. My intention was to just reset it using the link you provided. I can run this test tomorrow while the daughter is at day care. What I am really trying to accomplish at this point though is getting the tweecer to communicate with the computer. I have upgraded to 36lb injectors. Which means I should be smelling fuel somewhere along the line when cranking and I do not. To me this still indicates a ground or power supply problem. And as I learned on my Mustang, when you don't have the correct grounds the computer can become the ground. Which in turn took out my computer, Tweecer, and digital 6+ box all in one swoop. $1000 lesson learned.

jdsgallops
11-13-2013, 03:00 PM
Thank you David. Unplugged the cam sensor and tried cranking more than 3 times. Almost started once and popped through the exhaust once. I now know where the problem lies.

Unfortunately it is still turning over with the key very slowly (which is why it took more than 3 tries) on a fully charged battery. Still going to look at the ignition switch but the battery is dated Jul 09. Will get a full charge on it and then test it.

jdsgallops
11-14-2013, 01:14 PM
Ignition switch appears to be fine. No separation as described by S. Mazza.

Battery held a steady charge overnight even with below freezing temps. Was 12.59 las tI checked yesterday was 12.55 this morning. So it also appears to be good.

Which brings me back to what has always been an issue with this car. The alarm. It appears an aftermarket alarm was installed. At least it has an aftermarket remote. Any time the battery is disconnected then reconnected the lights flash and it seems to go into a no start mode. Cranking brings lots of buzzes and flashing lights. I have seen no actual black box for the alarm. Ideas/suggestions.

One other thought, I did have the dash pulled back for heater core install. May have forgotten to hook something back up?

Thanks again for any insight!

jdsgallops
11-20-2013, 01:48 PM
Ok guys got the cam sensor in correctly, well at least as close as I am able to, and still no start. Definitely smell fuel so it is a spark issue. Having lunch then going to check for spark and double check all wire connections again. Any other thoughts?