Page 1 of 3 1 2 3 >
Topic Options
#2427988 - 01/02/18 06:46 PM '84 Chrysler 5th Avenue conversion from computer to ecu
dfixer Offline
member

Registered: 01/02/18
Posts: 24
Loc: Texas
My 84 Chrysler 5th Avenue would not start - it would turn over fine but would not fire. I decided it was time to switch from computer the ecu. Bought a conversion kit from Jegs. Put it in and it worked first crank, just set timing and adjusted idle and it ran better than ever. That was November 29th and on December 22nd back to the same problem - turns over fine but will not start. Jegs tells me the kit was not designed for my lean burn. But if that is true, why did it wait for almost a month to decide it was not right for my car? Kind of wonder if the module has gone bad. I get battery on both post of the coil when the module harness is disconnected but when I connect the harness I get about 8 volts on the negative post and almost 4 volts on the positive post. Double checked all my connections and they look fine. What am I missing?

Top
#2428085 - 01/02/18 09:46 PM Re: '84 Chrysler 5th Avenue conversion from computer to ecu [Re: dfixer]
RapidRobert Offline
Circle Track

Registered: 11/20/03
Posts: 34405
Loc: Lincoln Nebraska
Welcome aboard. pull the yellow wire off of the starter relay to disable the starter & have a helper hold the key to "start" & see if the coil positive primary terminal/blue/yellow ECU terminal are hot (& near batt voltage) then have him release the key to "run" & see if they are still hot. seperate/reconnect the ECU pentastar connector/dist pickup zigzag connector & firewall bulkhead. Ohm the dist pickup for ohm amount/continuity. the coil positive primary should have more voltage than the coil negative primary terminal. How did you wire it up? this'll get us started. EDIT with a bit more thinking, you might be wired right ex the coil is backwards & it was OK when warmer but not when it got real cold OR the ECU mighta failed (it wouldn't be orange in color would it!). Ohm the ballast too but for that potential that would be a "run" side issue with maybe a hint of starting on the "crank" side till you let off the key & it goes back to the run "ballast" side.


Edited by RapidRobert (01/02/18 10:21 PM)
Edit Reason: bored
_________________________
live every 24 hour block of time like it's your last day on earth

Top
#2428172 - 01/03/18 02:26 AM Re: '84 Chrysler 5th Avenue conversion from computer to ecu [Re: RapidRobert]
dfixer Offline
member

Registered: 01/02/18
Posts: 24
Loc: Texas
Thanks for your quick response. I just got back to my computer, so I am afraid some of what you ask will have to wait till tomorrow when it is daylight and hopefully a little warmer. My helper is a she (wife) who likes milder temperatures. But I will answer/ask questions where I can this evening to help move things along. You say "separate/reconnect the ECU pentastar connector/dist pickup zigzag connector and firewall bulkhead." I guess this is what Jegs' kit instructions call the harness and by separate/reconnect do you want me to ohm the pickup first with it disconnected from the ECU and then with it connected to the ECU? As far as wiring: from the ECU harness the black with a yellow trace (#2 pin on ECU) went to the negative post on the ignition coil, the blue w/yellow trace (#1 pin on ECU) went to one side of the ballast resistor, from this same side of the ballast resistor I ran a new 14 gauge wire and spliced into the main ignition feed wire coming off pin 37 of the Master Disconnect Connector on the bulkhead/firewall, next I cut the wire coming out of the starter relay going to the "BAL" connection (taped up the non-connector side) and spliced a new 14 gauge wire to the "BAL" connected wire which I then ran to the other end of the ballast resistor, then from that same end I ran another new 14 gauge wire to the positive post of the ignition coil and pins #4 and #5 go to the zigzag plug of the dist. pickup coil. Yes, the ECU that came in the Jegs' kit is orange. There is no ". . .hint of starting on the crank". It just turns over fine but not even a hint of starting. Hope that answers your questions. I will try to fill in the rest of the blanks tomorrow. Thanks again for the help.

Top
#2428337 - 01/03/18 12:44 PM Re: '84 Chrysler 5th Avenue conversion from computer to ecu [Re: dfixer]
dfixer Offline
member

Registered: 01/02/18
Posts: 24
Loc: Texas
Yesterday the response I got from Jegs to my plea for help was that the kit I purchased was not compatible with the factory lean burn system. Today they sent me this message,"Thanks for your response. The lean burn systems have a separate ignition unit that should be removed; these kits such as the one you purchased are designed to replace the lean burn ignition. If the unit is defective, send it back and we will be happy to replace it." I guess they could mean it is not compatible if I just drop their kit in and leave the lean burn system intact. But the lean burn used a two pick up coil dist. and the dist. with their kit uses only one, so it should be obvious I did not leave the lean burn intact. That seems a bit confusing, but nice to know they are ready to stand behind their product. Things are warming up here so I should be able to run the test you asked for in a bit.

Top
#2428416 - 01/03/18 03:31 PM Re: '84 Chrysler 5th Avenue conversion from computer to ecu [Re: dfixer]
5thAve Offline
master

Registered: 01/19/03
Posts: 2785
Loc: Posts: 4034 - Register...
Im not sure what Jegs means by not being compatible. You are completely disconnecting the fuel control computer and replacing it with the ECU and new distributor. THe only un compatibility is you also need to get rid of the feedback carb but that shouldn't affect your sudden non running issue.

You can't start mixing things up and use a vacuum distributor with the original computer like you seem to be implying in your last post.

Top
#2428470 - 01/03/18 05:56 PM Re: '84 Chrysler 5th Avenue conversion from computer to ecu [Re: dfixer]
DarrenS Offline


Registered: 05/06/04
Posts: 571
Loc: Courtenay, B.C.
If you follow Roberts advice, you will be able to trace where in your wiring your problem lies.

If you had an intermittent non start it could be a loose wire. I had that happen in my Diplomat and it was the ignition switch on the way out...

It is likely not related to the lean burn (not that it is a terrible idea to replace it)

Top
#2428506 - 01/03/18 06:37 PM Re: '84 Chrysler 5th Avenue conversion from computer to ecu [Re: RapidRobert]
dfixer Offline
member

Registered: 01/02/18
Posts: 24
Loc: Texas
To the best of my ability and understanding, here are the answers to the questions Rapid Robert asked me to check on:
1. With the pentastar connected key in start, on positive post I read 7.56
2. With the pentastar connected key in start, on negative post I read 3.65
3. With the pentastar disconnected key in start, on positive post I read 11.35
4. With the pentastar disconnected key in start, on negative post I read 11.35
5. With the pentastar connected key in run, on positive post I read 7.46
6. With the pentastar connected key in run, on negative post I read 3.92
7. With the pentastar disconnected key in run, on positive post I read 11.39
8. With the pentastar disconnected key in run, on negative post I read 11.39
9. The dist. pickup does have continuity and reads 250 ohms
10. Yes the ECU is "Halloween pumpkin" orange
11. The ballast resistor reads 1.3 ohms
Just as reference, the battery voltage reads 12.10
Something I didn't mention yesterday is that I put in new plugs and wires the month before I did the conversion and I put in a new ignition coil at the same time as I did the conversion.
Thanks again

Top
#2428539 - 01/03/18 07:35 PM Re: '84 Chrysler 5th Avenue conversion from computer to ecu [Re: dfixer]
RapidRobert Offline
Circle Track

Registered: 11/20/03
Posts: 34405
Loc: Lincoln Nebraska
Check the reluctor gap (takes 5 seconds) . seperate the dist pickup zigzag connector & drag the male (bare) tip of the body harness half of that connector across the intake surface (ground) as you hold the end of the large coil to dist coil wire 1/4" from the intake (ground) with key "on" & key to "crank" with starter relay unplugged (yellow "ign" wire) see if the coil wire sparks. I dont think it will as I think the box has died but it is an easy check. Take all the wires off of the coil negative primary terminal (might just be one) & with a jumper wire with alligator clips on each end, connect one end to the coil neg terminal and tap tap the other alligator clip end to the intake & see if it makes the coil wire spark (in run & in crank, same deal there). I'm assuming the blue/yellow (ECU main feed) is hot also (I mighta missed that). It sounds like the infamous orange box has died. though I dont suggest shotgunning parts for diagnosing, I think I would get a cheap parts house 4 pin replacement & if it turns out that that ain't it, with the newer orange boxes' rep I would highly suggest a spare 4 pin ECU in the glove box.
_________________________
live every 24 hour block of time like it's your last day on earth

Top
#2428646 - 01/03/18 10:10 PM Re: '84 Chrysler 5th Avenue conversion from computer to ecu [Re: RapidRobert]
dfixer Offline
member

Registered: 01/02/18
Posts: 24
Loc: Texas
It sure seems to me that it is pointing to a defective ECU. However, once again night has overtaken me and we are headed back down into the 20's, so I will get the answers to your questions tomorrow. Following the instructions that came with the conversion kit, I did check the reluctor gap when I took the new distributor out of the box. It was no where near where it was suppose to be and with a brass feeler gauge I set it to .008 of an inch, as instructed. Of course it could have moved, so I will check it again tomorrow. Following my Chrysler service manual, I did try to get a spark out of the coil wire by momentary taps with a test lead on the negative post to ground with the coil wire 1/4 inch from ground, but it didn't call for me to remove the black/yellow wire from the negative post (the only wire on the negative post) and it only had me try it with the switch in the run position; nor did it have me try it with the zigzag connector. In every instance, with and without the harness connected, I never got a spark. Just to be sure, I will try everything you ask tomorrow. My question now is about the, as you said, ". . .infamous orange box." I am guessing the use of "infamous" in this instance is not a good thing. I know about carrying a spare part in the glove box. I also drive a '67 Corvair and never leave home without a spare belt and clutch cable. But I also know, with my luck, I will have just cut my hand off on the table saw and need to rush myself to the ER when the 5th Ave. will give me another no start. So are there better, more reliable boxes? I don't have to tear this conversion apart to send it in just to have them send me another orange box? Thanks

Top
#2428793 - 01/04/18 09:15 AM Re: '84 Chrysler 5th Avenue conversion from computer to ecu [Re: dfixer]
RapidRobert Offline
Circle Track

Registered: 11/20/03
Posts: 34405
Loc: Lincoln Nebraska
Actually if you pull the pentastar connector off of the ECU yes you dont have to take off the black/yellow wire from the coil neg primary post, just pull the coil wire out of the dist cap terminal & make/break jumping the coil neg primary terminal to ground with a jumper & see if the coil wire held 1/4 from ground makes sparks & I would do it in run and in crank. if it sparks then that tells you all is good ex for either the ECU, the dist, their respective wiring. then plug everything back in & drag the pickup body half male metal tip across the intake metal surface & same deal, see if the coil wire sparks in run and in crank & in fact I would do that first & if it sparks then the dist pickup is the issue but with you showing continuity on it I don't think it is the pickup but it is an easy first test (& yes this ain't a "factory" procedure) but it is safe/effective. The newer orange boxes do have a higher failure rate than the old ones did but we are the fixit dept so we (mostly) do get bad news here & it did run so it is wired right so K.I.S.S. (keep it simple sam) does point to the ECU as the culprit. & make sure the ECU is grounded well.
_________________________
live every 24 hour block of time like it's your last day on earth

Top
#2428801 - 01/04/18 09:28 AM Re: '84 Chrysler 5th Avenue conversion from computer to ecu [Re: RapidRobert]
moparx Offline
Dreaming of implants

Registered: 09/03/03
Posts: 9713
Loc: north of coder
where was the 12.10 battery voltage reading taken from ? if it was from the battery posts, that battery needs charged before continuing. if from somewhere else, you are losing voltage due to resistance. providing the battery is 12.6 or above at the posts.
beer

Top
#2429181 - 01/04/18 06:35 PM Re: '84 Chrysler 5th Avenue conversion from computer to ecu [Re: RapidRobert]
dfixer Offline
member

Registered: 01/02/18
Posts: 24
Loc: Texas
You gave me a list of things to try last night in you post at 7:35 PM, and of course, as I said, I would try them today in the daylight. This morning at 9:15 AM, you gave me pretty much the same list but letting me know with the pentastar connector off I did not have to pull the negative lead off the coil. I made a copy of those things to try and went down to the car. With the pentastar connector already off I tried the first set of questions. With the jumper on the coil negative post and first key in run then start position I got no spark from the coil wire dist connector at 1/4 inch from ground. Hooked everything up, pulled the zigzag connector apart, key in run then start and there was my spark at the coil wire end and your post said,". . .if it sparks then the dist pickup is the issue but with you showing continuity on it I don't think it is the pickup. . ." I thought WOW! I was so sure everything was pointing to the ECU. But then I thought back to the opening sentence on your post from last night, "Check the reluctor gap (takes 5 seconds)." For me, crawling back there takes more than 5 seconds, but sure enough, the gap was just about as bad as when I took the dist out of the box. I set it back to .008, put the cap on, plugged everything back together and it is running great again! I know when I tightened that screw the first time I did so till it felt like I might cam out the head and I did the same thing today. As I said earlier, I have a Corvair, actually two, so I have had lots of time under a dist cap and don't recall having a plate move out like that. Maybe I just didn't get it tight enough; it may happen again. But it is running once again (I did charge the battery up) and I sure appreciate everyone's help. I do have one small question. It looks like the pentastar connector and its mating jack are designed to have a screw down through the center to keep them from separating. I know there wasn't one in the hardware package in the kit, just wondered if it is suppose to have one.
Thanks again

Top
#2429185 - 01/04/18 06:53 PM Re: '84 Chrysler 5th Avenue conversion from computer to ecu [Re: dfixer]
RapidRobert Offline
Circle Track

Registered: 11/20/03
Posts: 34405
Loc: Lincoln Nebraska
Quote:
"Check the reluctor gap (takes 5 seconds)." For me, crawling back there takes more than 5 seconds. On the screw down thru the center I know there wasn't one in the hardware package in the kit, just wondered if it is suppose to have one. Thanks again
When you get up in your 60's you will be able to slide in & out of there like a ninja in 5 seconds (or less). That screw is a preventative piece but I cannot say I have ever seen one come off of there. it is a weird thread count (iirc) but I'm sure your hardware store could fix you up. EDIT The coil would have to have sparked with you making/breaking jumping the neg primary post to ground. definitely check the plate lockdown screw cuz if it loosened once likely it will do it again cuz you tightened it up good both times. You might have to tap a new hole or possibly jam a slightly larger screw in there till it gets secure.


Edited by RapidRobert (01/04/18 06:59 PM)
_________________________
live every 24 hour block of time like it's your last day on earth

Top
#2429343 - 01/05/18 02:59 AM Re: '84 Chrysler 5th Avenue conversion from computer to ecu [Re: RapidRobert]
dfixer Offline
member

Registered: 01/02/18
Posts: 24
Loc: Texas
"When you get up in your 60's. . ." Are you kidding me? I am so far past those years, I can't remember whether they were fun or not. I am still puzzled by not getting a spark when using that negative post troubleshooting. I had run that test so many times with the same result, I was almost happy to see it spark when using the zigzag connector method. As much as I wanted it to spark, tried to get it to spark and all those times not once did I see a spark; but the first time with the zigzag, there it was. It just concerns me that somehow I might still have something not quite right. I am equally worried about that screw holding the pickup coil in adjustment. Both times I feel like I tightened it down as far as I could go without making the head of the screw look like one of those security screws used on urinal petitions in guys' restrooms. Like you, I am thinking I may have to change that screw out for something more substantial. But for now I will concentrate on getting it all put back together, re-dressing all the wires, order a spare ECU for the glovebox but most of all, enjoy driving my 5th Avenue that has been given a new lease on life(that I hope will last longer than a month this time). Again, thanks all of you for your help, especially your patience Rapid Robert. . .couldn't have done it without you.

Top
#2429424 - 01/05/18 10:28 AM Re: '84 Chrysler 5th Avenue conversion from computer to ecu [Re: dfixer]
moparx Offline
Dreaming of implants

Registered: 09/03/03
Posts: 9713
Loc: north of coder
double R is a GREAT source of help, and will assist anyone. bow glad you got your 5th avenue going !
beer

Top
#2429678 - 01/05/18 08:22 PM Re: '84 Chrysler 5th Avenue conversion from computer to ecu [Re: dfixer]
RapidRobert Offline
Circle Track

Registered: 11/20/03
Posts: 34405
Loc: Lincoln Nebraska
MoparX thank you for the kind words. dfixer, Here I thought I was talking with a YOUNG man!. If it runs it is wired OK (in this case). For future (diagnosing) reference, (1) with all (can be just one like yours) wires off of the coil neg primary terminal terminal (2) key (A) on or (B) key to crank (3) tap tap the jumper wire you use, to ground (4) the coil wire end 1/4" from ground will/must spark if the coil is good & it is being fed (& it is in this case). the pickup zigzag connector you can get by with just dragging it across the intake surface to make/break contact. IIRC the screw is an 8-32, 3/16 long & if you have to redo the threads I would remove the center clip the pull the reluctor up & off the shaft WHILE pressing down on the shaft so the shaft/slotted plate does not come up off of the pins, then you can undo everything & seperate the 2 plates to drill/tap the hole in the upper plate (if needed).
_________________________
live every 24 hour block of time like it's your last day on earth

Top
#2430191 - 01/06/18 06:47 PM Re: '84 Chrysler 5th Avenue conversion from computer to ecu [Re: RapidRobert]
dfixer Offline
member

Registered: 01/02/18
Posts: 24
Loc: Texas
Not only am I not young, this 5th Ave. is about to put me in my grave. Yesterday I decided to take it to town because it was near empty on fuel. Boy it started right up and away we went - about 8 miles round trip. When I got home I started and stopped it several times; there seemed to be a slight vibration, not as smooth as it usually is at idle. This evening, while I was fiddling around out in the yard, I decided to start it up to see how it was doing and I am right back to square one; turns over but will not start. Of course I thought it was that screw again but no, the gap is fine. It's dark now, so I guess I start all over again tomorrow. Hope you'll stay close. Thanks

Top
#2430233 - 01/06/18 08:16 PM Re: '84 Chrysler 5th Avenue conversion from computer to ecu [Re: dfixer]
RapidRobert Offline
Circle Track

Registered: 11/20/03
Posts: 34405
Loc: Lincoln Nebraska
I promise, first when the time comes, lets see if it sparking at the plug wires when someone cranks it.
_________________________
live every 24 hour block of time like it's your last day on earth

Top
#2430614 - 01/07/18 02:44 PM Re: '84 Chrysler 5th Avenue conversion from computer to ecu [Re: dfixer]
dfixer Offline
member

Registered: 01/02/18
Posts: 24
Loc: Texas
There is no spark at plug wire #1. Pulled the wire off that spark plug, put in one of the old ones I just replaced (which really wasn't that worn), pushed it against the intake and my assistant cranked the engine. I moved the plug some on the intake to be sure it was making good contact but still no spark.
Just for info, I looked back over my maintenance records for this year and in addition to this conversion kit, I have changed the plugs, plug wires, cap and rotor (which were replaced with the cap and rotor in the kit), windshield wiper bushings, alternator, fuel pump, fuel filter, of course oil and filter, air filter, belts and hoses, carburetor repair kit, exhaust & emission control duct hose and fresh air intake hose. I retired in November of 2016, and wanted to get it ready to go the rest of the way with me (my sister and brother-in-law bought it new in '84 - I bought it from them in mid 1995).
What would you like for me to try next?

Top
#2430651 - 01/07/18 03:59 PM Re: '84 Chrysler 5th Avenue conversion from computer to ecu [Re: dfixer]
RapidRobert Offline
Circle Track

Registered: 11/20/03
Posts: 34405
Loc: Lincoln Nebraska
Lets go thru our std tests. disable the starter. drag the zigzag dist pickup connector on the intake & see if the coil wire sparks in run and in crank. if it does not spark then we'll jump the coil neg primary terminal to ground (tap tap tap) & see if the coil wire sparks in run & in crank (& it will clarify that test for us cuz with it running it had to have sparked). If dragging the zigzag connector does NOT spark the coil wire then we'll attack the dist. this'll get us started.
_________________________
live every 24 hour block of time like it's your last day on earth

Top
Page 1 of 3 1 2 3 >

Advertisement
Forum Stats
25,631 Registered Members
32 Forums
195,641 Topics
2,288,874 Posts

Most users ever online: 1,424 @ 06/20/18 07:18 PM
Moparts Newest Topics
1969 Plymouth Road Runner
by tomsjack
12/15/18 02:47 AM
How I keep track of my "Barn Finds"
by Devil
12/14/18 11:43 PM
361 bb stroker
by orange elephants
12/14/18 10:57 PM
charger Rallye dash cluster bulb locations
by lockjaw-express
12/14/18 10:42 PM