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88 W100 5.2 TBI troublshooting help
Posted By: dodgedart67
88 W100 5.2 TBI troublshooting help - 09/26/13 10:14 PM
I have a 88 W100 4x4 with a TBI 318, it just quit running and now will not start, I can jump the ASD relay out and make the fuel pump run and get 12 volts at my injectors but under normal ignition switch operation trying it with a noid light plugged in it doesn't flash, when the switch is first turned on I do hear the fuel pump run for about a second or so but it doesn't ever start...I am not very familiar with this set up I am more of a carb guy, any help grwatly appreciated.
Posted By: 340SHORTY
Re: 88 W100 5.2 TBI troublshooting help - 09/26/13 10:34 PM
replace the Hall Effect Sensor...
Posted By: dodgedart67
Re: 88 W100 5.2 TBI troublshooting help - 09/27/13 01:17 PM
I'll try that and let you know.
Thanks!!
Posted By: herkamer
Re: 88 W100 5.2 TBI troublshooting help - 09/27/13 06:32 PM
Same thing happened to my Ramcharger. Ran one day, wouldn't start the next. Replaced hall effect and been running fine since.
Posted By: dodgedart67
Re: 88 W100 5.2 TBI troublshooting help - 09/28/13 01:40 AM
Well I replaced the hall effect and it still will not start, it sounds like it's going to hit but never does
Posted By: jerseybud
Re: 88 W100 5.2 TBI troublshooting help - 09/28/13 02:51 AM
Usually the hall sensor is the culprit but I've been burned on a double whammy on my 88 with a map and hall effect at same time
Check for codes
Check the fuel pressure- should be 14.5 +/- 1
Check for spark
get back to us
Posted By: hp383
Re: 88 W100 5.2 TBI troublshooting help - 09/28/13 03:35 AM
Are you getting spark from the coil?
Power on both sides of the ballast in the run position?
Posted By: dodgedart67
Re: 88 W100 5.2 TBI troublshooting help - 09/28/13 04:47 AM
Don't have a ballast
Posted By: 340SHORTY
Re: 88 W100 5.2 TBI troublshooting help - 09/28/13 05:42 AM
have you checked for codes ?? is your timing off ??
Posted By: dodgedart67
Re: 88 W100 5.2 TBI troublshooting help - 09/28/13 03:29 PM
I havent checked codes, it turns over like it always did, it just quit going down the road
Posted By: dodgedart67
Re: 88 W100 5.2 TBI troublshooting help - 09/28/13 09:49 PM
I have nothing at the coil
Posted By: 340SHORTY
Re: 88 W100 5.2 TBI troublshooting help - 09/29/13 06:10 AM
oh oh
its really broke...
Posted By: 340SHORTY
Re: 88 W100 5.2 TBI troublshooting help - 09/29/13 07:37 AM
I think I have a computer that you can have, just pay the freight.. I will look tomorrow..
Posted By: dodgedart67
Re: 88 W100 5.2 TBI troublshooting help - 09/29/13 05:18 PM
I would be willing to pay you something more than freight
Thanks
Posted By: dodgedart67
Re: 88 W100 5.2 TBI troublshooting help - 10/04/13 12:51 AM
I guess no computer
Posted By: 340SHORTY
Re: 88 W100 5.2 TBI troublshooting help - 10/04/13 01:37 AM
Been looking but it wont jump up and say here I am..
Posted By: dodgedart67
Re: 88 W100 5.2 TBI troublshooting help - 10/04/13 03:10 AM
I understand that
let me look in the majic shed..I may have a 88 5.2 pcm you can have also. I let you know.
Posted By: dodgedart67
Re: 88 W100 5.2 TBI troublshooting help - 10/05/13 03:05 AM
Thanks
Posted By: hp383
Re: 88 W100 5.2 TBI troublshooting help - 10/05/13 03:36 AM
Have you tried swapping in a known working coil? Might still be an easy fix.
yes,i have the one from my 88 truck on the shelf. shoot me your addy and i will send it, you cover the ride for it.
yours does have the 2 plugs correct? look like this?
Posted By: dodgedart67
Re: 88 W100 5.2 TBI troublshooting help - 10/07/13 02:45 AM
I have not tried another coil, I sent you an email scratchnfotraction
got it
i will get it on the way for you.
i have a good used coil from the 88 also, I will toss it in there with it.
Posted By: dodgedart67
Re: 88 W100 5.2 TBI troublshooting help - 10/11/13 05:49 PM
Well so far I have replaced the hall effect, ASD relay, coil and computer and it still won't start
Posted By: herkamer
Re: 88 W100 5.2 TBI troublshooting help - 10/11/13 06:39 PM
Start with the basics:
Do you have spark?
Do you have fuel pressure?
Are the injectors firing? You may need to use a timing light to see that.
All connections solid?
Any codes on the computer?
That's where we will be able to get into diagnosing what the problem is.
Posted By: dodgedart67
Re: 88 W100 5.2 TBI troublshooting help - 10/11/13 07:07 PM
fuel pressure is ok, I made it run to check, I have no power at the coil, so the first thing I changed was the ASD relay because mine was busted, then the hall effect, then coil, computer, re did all fuseable links as well
Posted By: therocks
Re: 88 W100 5.2 TBI troublshooting help - 10/11/13 07:38 PM
Check the ignition switch itself.Its down on the column.Not the key switch.Also check the fuses.My Ram burned up the switch and no start.I had to take the connector apart and redo some ends when I replaced it.Rocky
Posted By: herkamer
Re: 88 W100 5.2 TBI troublshooting help - 10/11/13 09:44 PM
Send me a PM with your email. I have some troubleshooting pages out of a service manual.
Posted By: dodgedart67
Re: 88 W100 5.2 TBI troublshooting help - 10/11/13 11:51 PM
pm sent
Posted By: superwrench
Re: 88 W100 5.2 TBI troublshooting help - 10/12/13 06:58 AM
Quote:
Well so far I have replaced the hall effect, ASD relay, coil and computer and it still won't start
.....Then I'm going to say that you have an open (corroded) wire in the main harness to the computer. It's not uncommon for battery residue to contaminate the harness...which causes havoc on wiring splices within. I'm willing to bet that there is a 12V feed wire to the computer that is rotten.... 
(White and red wire)
Start opening the harness near the battery and continue along till you're positive that all is OK. 
Posted By: dodgedart67
Re: 88 W100 5.2 TBI troublshooting help - 10/12/13 03:18 PM
I have checked some but not all, I did redo all the fuseable links to make sure they were good I know they cause trouble too
Posted By: superwrench
Re: 88 W100 5.2 TBI troublshooting help - 10/12/13 05:02 PM
Just start peeling back all the tape on the harness....it may be tedious, but at this point you've obviously wasted a lot of time and still gotten nowhere.
You should get a wiring schematic for that model.....You'll see what are the 12V feeds and grounds very quickly. At this point you have obviously lost power, or a major ground.
Posted By: therocks
Re: 88 W100 5.2 TBI troublshooting help - 10/12/13 07:46 PM
superwrench is right on the harness.I had a 2.2 at work that was no start etc.Lost a major ground and would not start or spark the coil.It would crank all day.Ive fixed a lot of splices at work in the last 30 years.Rocky
Posted By: superwrench
Re: 88 W100 5.2 TBI troublshooting help - 10/13/13 01:50 AM
Yep....I think I fixed a harness problem in the 91 to 96 Dakotas about every week!!! Same scenario with a rotten splice.....good money maker especially when you were working at the "Electrical" rate...!!! LOL
Posted By: therocks
Re: 88 W100 5.2 TBI troublshooting help - 10/13/13 01:49 PM
SW GMs were famous for the headlight grounds.I dont know how many Cavalars and Sunfires I fixed.Ford was also known for corrosion in their plugs.Here in the rust,salt belt it was common.The green death took its toll on a lot of wiring.Rocky
Posted By: RUNCHARGER
Re: 88 W100 5.2 TBI troublshooting help - 10/13/13 04:41 PM
Good info guys. My son just brought home a $150 no-start 88 V6 Dakota. We'll try try to figure it out today.
Sheldon
Posted By: dodgedart67
Re: 88 W100 5.2 TBI troublshooting help - 10/14/13 02:01 AM
So far I have found one fuseable link that I missed that pulled apart and a couple splices that someone has already soldered but still havent found the problem.
Posted By: RUNCHARGER
Re: 88 W100 5.2 TBI troublshooting help - 10/14/13 07:54 PM
We got lucky on ours. The fuel pump ran but would shut off right away, no spark but the computer threw a few unrelated codes (like battery recently disconnected). We figured it had to be the hall effect sensor and it was. He's got a good rustfree V6 Dakota 4X4 for total investment of $155. Hope you get yours figured out.
Sheldon
Posted By: dodgedart67
Re: 88 W100 5.2 TBI troublshooting help - 10/19/13 08:05 PM
Well I have ran down the entire wiring harness and repaired a few questionable spots, everything that can be ohmed has been and is ok now, I have never had this much trouble finding a problem, think I will either sell it, put it in the back building for a while(tired of looking at it for now) or change it over to carb with regular ignition, no computer, I have most everything I need I think, even have a gas tank from an older truck without in tank pump, I appreciate all the input from everyone.
Thanks!!
Posted By: superwrench
Re: 88 W100 5.2 TBI troublshooting help - 10/19/13 09:20 PM
One thing you said way back in this post was that it "tried" to "catch".....Any chance that the timing chain has jumped or broken??? Have you checked to see if the rotor is in fact turning??? Or that it is not in phase (i.e. the chain has jumped)??
I'm not dead positive but I think the Hall effect gives the signal to the computer to turn on the power to the ASD/coil+ when cranking. If the distributor is not turning.....
The ASD will always power the pump and coil up for a second when the key is first turned on. From there the computer needs to see a cranking reference (Hall signal) to start.