Strange DIS problems

[SHOtimer]

For the last 9 months and 10k miles I have had a starting problem, never a running problem. The car would have extended cranking times, or multiple cranks, it would backfire through the intake and bind up during cranking. I posted these problems several times and was always told it was my CID sensor. So, I have replaced that sensor 6 times in 10k miles, never made a difference. So, I bought a used DIS from another forum member and tried it, worked fabulously, no more back firing or binding, only gives me problems now when hot outside. Anyways I tried the old DIS again and it had the same symptoms so I labeled that one bad and put it in a corner. Ordered a new one from FPN, so that it could have a nice new one, put the new one on same symptoms return (intake backfire, binding). So, I put the used one I purchased back on and all the problems go away! The only difference between the two DIS modules is the used one says "Motorcraft DIS" in huge print in the middle of the module and the new one says it a lot smaller on the top left corner. I am stumpted to what is going on and why it only works with old parts not new ones. Thanx for reading this far and hope someone has an answer.
Doug

 

[projectSHO89]

Which Motorcraft DIS part number did you receive?

Steve

 

[masho95]

Did you ever check the codes? Have you ever checked the fuel pressure?

 

[SHOtimer]

The part number on the side of the box for my new DIS is "DY-958" under that it says "1U2Z-12A297-CB" I looked over the used one I bought which works and no numbers correspond. Yes, I have ran codes over and over, along with cylinder balance tests and everything comes up clear. I have a new fuel pump also and pressure is fine.
Doug

 

[projectSHO89]

DY-958 is the (edited) new part number.
w
SHO DIS Module Old Part Numbers

<small>[ July 16, 2003, 07:33 AM: Message edited by: projectSHO89 ]</small>

 

[shojuan]

Do you have a thin layer of heat sink grease between the DIS module and the intake or are you just putting them on with both surfaces absolutely clean? You need that heatsink grease there otherwise you will have problems. Also make sure the surfaces between the 4 little DIS screws and the intake are absolutely clean and if not then clean them up with some sandpaper. The next spot for grounding problems would be the two intake crossover tube bolts and after that the ground strap to intake strap (kind of hard to reach) on the passenger/firewall side of the intake.

Also some fancy heatsink grease might improve things. All heatsink greases are not created equal. You can go to Frys Electronics over to where they have the CPUs and memory and look for "Arctic Silver" brand heatsink grease. Or Arctic Silver II (maybe they even make a III now? shrug ) Can also mail order that stuff.

 

[SHOtimer]

THANK YOU I have had the DIS replaced numerous times and it has never worked...we duh they are the wrong ones. Well, I ordered this from FPNs list, so they are listing the wrong one for the SHO. Yes, I am using heat sink I bought at radio shack, all my contacts are clean and I have antiseize on the DIS screws and crossovertube bolts. THANK YOU AGAIN!
Doug

 

[shojuan]

If you run into more problems then try cleaning all the antiseize off of the DIS screws and crossover bolts. You really need to have a good electrical connection at those points and while the antiseize is good for preventing galling of the threads, it might not be the best conductor of electricity. I wonder if anybody has actually tested that stuff for its conductivity?

Anyways, leave it to Steve to solve the electronic problems! thumb beer thumb

 

[SHOtimer]

I just checked SHO-nut and it lists the DY-958 as the correct DIS along with FPN, and I entered the DY-655's part number in at FPN and it came up as an unvalid number. To make sure I have this right, FPN is wrong along with SHO nut saying that the DY-958 (1U2Z-12A297-CB) is the correct DIS for the SHO when it isn't and that the DY-655 (F1SZ-12A297-B) is the correct one?
Doug

 

[SHOtimer]

It is just a real thin coat, not thick at all, don't want anymore smoke anyways...
Doug

 

[shojuan]

SHOtimer:
It is just a real thin coat, not thick at all, don't want anymore smoke anyways...
Doug

Hey, I warned you about that smoke didn't I? I just hope you rolled the car out of the garage before starting it up for the first time! eek!

 

[shojuan]

I just found this: http://www.shoclub.com/DIS-ignition.htm

 

[projectSHO89]

shojuan:
I just found this: http://www.shoclub.com/DIS-ignition.htm

In that case, I withdraw my previous post with the "old" correct numbers. I was unaware that a new number was in existance. I will note that they are the "correct" old numbers.

Thanks for the heads-up.

Steve

 

[SHOtimer]

No, I started it in the garage then backed it out. Glad I did, might have set off the smoke detector . So, this is a *new* part number and part, is their a solution to my problem? Thanx,
Doug