90 electrical problems

[bryantaylor]

just bought a 90, not running. it was sitting for a couple of years, ran when parked. but now the fuel pump doesnt work. if you spray starting fluid into the intake it run start for a second or two, then cuts off. it has a brand new pump, i took it out and tested it, and it does work. put in a new fuel filter too.
here is where it gets interesting. i jumped the fuel pump and ground on the test port and pump doesnt turn on, not a big deal, i was expecting that. but when i jump the test and ground to run the codes, nothing. the CEL just stays on, it doesnt flash at all. i will pole around some more on it tomorow to see if i can find anything. anyone have some suggestions on things to check?

 

[naval-avi8or]

Make sure the safety switch in the trunk hasn't been popped.
Check the ccrm/fuel pump relay circuit is recieving and sending power to the pump.

 

[bryantaylor]

the switch is still pushed down. and i have hit the ccrm like i have read about and i can hear it click like 2 seconds after you turn the key on

 

[shovermont]

yo when i bought mine i had the same issue. bad injectors. mine were clogged, all six. i could spray starting fluid in and it woud work as well, be careful with that stuff though. bad for valves. bad case but just keep that in your mind if nothing comes of it.

 

[naval-avi8or]

Can you hear the pump when you turn the key from off to run. Pump should run for 2-3 seconds. You can also short the fuel pump circuit at the EEC connector and take a fuel pressure reading. This will at least determine if its the pump or not.

 

[bryantaylor]

the pump doesnt turn on, even if you kump the test connector. and it is a new pump and it works. i took it out to test it

 

[93rev2sev]

After 2 years your elecrical system might have been chewed up by vermin.

When I bought my silver 93 after it had been sitting for only 4 months, it was infested with mouse nests.

When I bought the 95 Contour after it had been sitting for 6+ months, it was infested by mice AND bees nests.

 

[bryantaylor]

everything appears to be intact, but i will jack it up and look at the underside today

 

[naval-avi8or]

I would suggest checking the fuel pump circuit for power. it will require you to have an assistant, since it will only activate for a few seconds at key to run. Can some of the GEN I owners verify this but I thought the GEN I used a stand alone fuel pump relay. If not can somebody post the pin/wire colors for the fuel pump circuit from the CCRM to the Fuel pump.

Keep in mind the following info is from the 93 3.0L SHO EVTM thats the earliest I have. So wire colors and pin numbers may not be the same. Also fuse names and amprage may be different.
Check all the Fuses (easier than telling you exaclty which ones) there is a fuse for the 30 amp PCM Relay/Fuel pump, 10amp IGN COIL and 50amp Cooling FAN (all are power to the CCRM and the Cooling Fan is the power for the LFP which is the primary fuel pump cicuit during start and grounding via the Data link connector) located in the engine compartment. Then if CCRM's are the same pin #5 PK/BK is power to the pump this wire is spliced to after the CCRM (to the fuel pump man of the PCM, controls hi/lo fuel pump operation) and them procedes to the fuel pump via the inertia switch in the trunk, pin #12 is HFP to the CCRM, Pin # 10 is LFP to the CCRM. When you short the fuel pump at the VIP DATA link connector it grounds the low pump relay. There is a chance that the Low relay circuit in the CCRM is not functioning (and all though a smack test may work for some it is not a 100% pos troubleshooting tech nor will you find it in any troubleshooting procedure). That being said it could be the CCRM or the PCM since they both interact for the fuel pump operation. That should at least get you started in the troubleshooting process.

To bad I don't still live in JAX this would be alot easier.

 

[bryantaylor]

jacked it up. all the wiring and plugs look fine. i unplugged the safety switch in the trunk and just jumped the wires. the smaked the CCRM several times and it never helped. do the gen 1 cars have another fuse box besides the small one by the pedals? i cant find one in the engine bay. i am starting to think it is the CCRM. i will try to borrow a firends and put it in and try that first

edit: i am starting to think the computer or ccrm or both might be bad. like i said above, i cant pull codes. i will jump the test pin and the CEL just stays on, doesnt go off, flash or anything.

 

[naval-avi8or]

do the gen 1 cars have another fuse box besides the small one by the pedals? i cant find one in the engine bay

If its where the GEN II's are it will be located outboard of the large round vacuum drum of the brake master cylinder.

 

[bryantaylor]

well i took the ccrm from my friends running 93mtx and still nothing. and i tryed plugging in my code scanner to run codes, and it still isnt responding

 

[naval-avi8or]

YES you do have a fuse block under the hood somewhere they don't run the HIGH AMP fuses into the cabin and then back to the engine compartment.

Check Pins #10 BK/O wire LFP PWR (#1 BK/O wire LFC and #2 BK/Owire LFC PWR are fed from the same fuse as #10) and #12 Y wire HFP PWR (#8 Y wire Vehical PWR and Pin #1 of PCM Y wire KAPWR) for 12 VDC. Pin #13 R/LG wire of CCRM is the PCM relay pwr. As stated earlier Pin(s) 10 (1 &2) are fused thru 50amp Cooling fan fuse, Pin(s) 12 (13 & PCM 1) are fused thru 30amp PCM Relay/Fuel Pump Fuse and Pin 13 is fused thru 10amp ING Coil fuse.

All should have 12V, Pin 13 is fused thru 10amp ING Coil fuse is HOT IN START OR RUN ONLY and the others are HOT AT ALL TIMES.

Use a test meter and make sure you have 12vdc where you are supposed to. Don't just throw parts at it cause it will/may get expensive.

If you have 12vdc at above then check for 12vdc @ PIN # 5 PK/BK (this one you willl have to check thru the PK/BK wire insulation with the CCRM connected @ key to run initiation or fuel pump testing circuit grounded TN/LG wire on VIP DATA Connector).

If you have power at PK/BK wire check both sides of inertia switch PK/BK wire for 12vdc. If you have it there then last but not least check for 12vdc at pump connector.

 

[naval-avi8or]

Can any GEN I guys confrim whether the is or is not a external fuel pump relay on the GEN I. I faintly remember it being mentioned along time ago. I don't want to be giving him troubleshooting advice that doesn't apply since all I have to go by is a GEN II EVTM.

 

[bryantaylor]

i think i will try and get another computer. i think the root of the problem is coming from that for the fact that i cant pull codes at all. it have done the jumping wires and plugged in a actuall code scaner and it doesnt respond at all. and because i put in a known good CCRM and it still wouldnt let me pull codes or start the car. do the computers on these go out?

 

[naval-avi8or]

Be advised Throwing parts @ it can get EXPENSIVE and frustrating. Especially when you find that $1-2 fuse/relay thats the real problem. Remember I mentioned the PCM realy PWR fuse several times could also prevent you from running the diagnotic check on the PCM.

 

[SHO-NUF93]

All I can say is that he has no fuse box behind the driver's side strut tower(next to the brake booster) where my car does: instead there is a lone relay switch plugged into the harness, with no bracket.

I was kindof stumped. Here is my thought process on this situation: while we did wait over the minute the scanner manual said to wait for KOEO codes, we got no blinks whatsoever, not even the 11 'all clear' code. Which may lead me to believe the PCM is faulty, or unpowered/ungrounded. BUT, the car will run on starting fluid.

Bryan, I guess since you now know what wire from the CCRM powers the fuel pump(via the post 2 above mine), probe it there, at the CCRM. It is possible to have a dead wire...but I've said this already...

BTW, I was the guy who lent him their CCRM, with no luck.

And wow, 2 posts between me reading and posting this.

 

[naval-avi8or]

All I can say is that he has no fuse box behind the driver's side strut tower(next to the brake booster) where my car does: instead there is a lone relay switch plugged into the harness, with no bracket.

I know there is a fuse/relay box somewhere bad part is like you said it's not where they put it on the GEN II's. and that relay you speak of is the one I elude to as the one I think I have heard mentioned years ago possibly being the fuel pump relay. Sure would be nice to have a GEN I EVTM about now.

I guess all the GEN Iers are fast asleep on the east coast.

 

[bryantaylor]

lol, you said probe

but anywho, i have looked all over the engine bay and cant find a fuse box anywhere. i will look around some more tomorow for any loose grounds and/or anything unpluged.

the ecu is behind the glovebox, right? i will check and see how easy it is to pull that. and see if they are cheap at the u-pull-it yard. i should pull it out anyway to look at the plugs for anything off there too

 

[naval-avi8or]

OK I just found the EVTM diag on autozone.com for the 89-90 3.0L SHO. NO FUSE BLOCK, insted they are all fusable links (bitch cause they are soildered and heat shrinked into the harness). It doesn't give pin numbers only wire colors and they are all the same. PROBE (since you like that word) ,the keyed to ignition switch, R/LGreen wire for 12 vdc, then PROBE BK/O (all three of them) and Yellow for 12vdc HOT ALL THE TIME. Then check for power out to pump BK/PK for 12vdc (don't forget the key or gnd data link connector).

Heres the dia add and then scroll down to fig 20

http://www.autozone.com/az/cds/en_us/0900823d/80/0d/30/88/0900823d800d3088/repairInfoPages.htm