why would noise cap cause engine to turnover but not start

[jramirez35]

Fellas,

Getting a "engine turns over but does not start" issue on my 90 5.0. part called noise cap in Haynes chapter 12-39 is broken off at the base of the unit. it is in the same wiring loom as the coil and says that it connects to tfi ign module.

1. where do i get a replacement for this (autozone and oreilly's does not have it) and

2. i thought this was to eliminate noise on the radio when reving up. what does that have to do with ign system or am i all wrong? the wire in the loom is red/lt grn.

any assistance would be appreciated.

 

[miesk5]

yo J;

If it grounded it could have popped fusible link "S" causing your issues. Other than that no it would not affect the performance.

Also look @ the ignition suppression resistor (22k ohm resistor) it's in the negative coil wire portion and is connected to the tach pickup for the instrument cluster, and the IDM circuit w/ the 22k ohm resistor

It's a 22k ohm resistor, 1/4-Watt rated. Get a meter & measure it - has to be 22k ohms +/-5%, replace it with another resistor from Radio Shack

If it's open, there is no ground path for the coil primary and TFI; see this diagram by Dustin

http://ylobronc.users.superford.org/documents/ignition.gif

This is a typical fusible link pic by shift1313 (Matt)http://i268.photobucket.com/albums/jj39/shift1313/89%20Bronco/PB020003.jpg

 

[Elmo]

How are fuseable links rated ? Cant they be replaced with an inline fuse holder with a same amp rated fuse ?

 

[Seabronc]

How are fuseable links rated ? Cant they be replaced with an inline fuse holder with a same amp rated fuse ?

Elmo,

Please start you own thread when you have a question.

>-

 

[jramirez35]

Well no dice on the possible blown resistor and fusible link. I went ahead and replaced the ignition coil because it turned out i was also getting no spark. i was curious if the cap is used as part of a gnd ckt and if that may be why it is causing an issue. i hate to buy stuff and find it fixed it...not really troubleshooting like that. Right now i am sitting at a new coil but no spark and am getting ready to buy the ICM but it looks like a bit of bear to get off. Any suggestions would be appreciated...gonna look at the previous threads for no start conditions for some help.

 

[Seabronc]

Here is an ignition trouble shooting procedure. It is for a 92, but should work for your truck also.

Good luck,

>-

 

[jramirez35]

Seabronc,

Thanks for the quick response...i was happy to see you logged on and i felt i might get a quick reply. Ok, in back tracking what i have done, this all started out with the replacement of a battery and a starter solenoid. I am very positive that i replaced the wires (multiple ones from previous owner splicing things together) on the positive side of the solenoid. The new solenoid would continue to turn the engine over even with the key removed but i did not get it to start. I naturally put on the old solenoid and got the present indications...this baby was running that morning and i went out to move it for the neighbor when i got the click of a bad battery. Since it stood still for a couple of months i thought the click was from a bad solenoid and not the battery since it was only a year old. turns out i was wrong and even worse the replacement solenoid introduced a new issue. I am not sure if the grounds are connected properly and would like to know if i may have crossed something from the solenoid to possible the eec module (my haynes module shows a ground from the -post on the battery) but with so many different splices, i have to dig way back in the loom to verify things and even then the color codes from the haynes manual do not match what i have in my hands. Practically every schematic that is posted up to assist me has been dead on so i assume y'all have shop manuals. Any more assistance would be appreciated and i hope i am not getting to be a bother. i dont think this needs to go to a mechanic...i think i have crossed something.

 

[Seabronc]

Those diagrams are from the EVTM (Electric and Vacuum Troubleshooting Manual). They were produced primarily for dealer service departments, but are now available on eBay from guys that deal in old vehicle manuals. You can also find complete shop manuals that go into detail on the Engine, Chassis, etc. I did a search tonight and didn't get a hit on your year truck.

OK, I want to clarify the symptoms as I am getting a little confused. What I understand, IS:

1. With the existing start relay the engine turns over when you turn the key switch to START

2. You checked to see that you have a spark at the plug.

3. You followed the check procedure I gave you from the EVTM.

4. Between the initial problem and now, as far as changes are concerned, all you have done is to change the start relay.

5. All wires on the start relay are on the battery side with the exception of the one to the Starter and the red with blue stripe that is connected to the pick coil of the start relay.

>-

 

[jramirez35]

Seabronc,

i did not attempt the repair procedure yet and will get that done soon. the wires to the original starter relay are as you described with the red/blue on the coil of the relay and the 12v leads on the batt side. the starter cable is on the other side of the relay. the 12v leads that i have are splices but they splice up with fusible links to 5 different 2ga yellow wires. I do need to repair some of those splices already so that is in the plans for corrective maintenance. i do not have spark right now and i replaced the coil as the first step to solving that issue. was gonna do the icm module but saw your responses and decided to wait for advice before i take out the distributor. i will attempt the procedure you posted and see if that solves the dilemma. To clarify, this vehicle started out with replacing the battery and starter relay on the bulkhead when i noticed the radio cap lead hanging there...that is why i thought this was an issue. It started prior to all this with a jumpstart from my f150 and then all **** broke lose. thanks for the help to date and look forward to your response.

 

[jramirez35]

let me directly answer your questions before i get back to the 9to5 and get off lunch break...

OK, I want to clarify the symptoms as I am getting a little confused. What I understand, IS:

1. With the existing start relay the engine turns over when you turn the key switch to START yes it does

2. You checked to see that you have a spark at the plug. i have no spark right now. replaced the coil thinking that was the issue but no corrective results to report

3. You followed the check procedure I gave you from the EVTM.i have not attempted this yet

4. Between the initial problem and now, as far as changes are concerned, all you have done is to change the start relay.no i changed the coil and battery and reinstalled the original starter relay

5. All wires on the start relay are on the battery side with the exception of the one to the Starter and the red with blue stripe that is connected to the pick coil of the start relay.i believe all of them are correctly installed. I have 5 leads attached to this side of the relay, one to the starter, and the red/blue to the coil of the relay.

Thanks so far for all your assistance, i appreciate it.