# 89 Hardbody questions



## mazdaverx7 (Dec 20, 2005)

i just picked up an 89 Hardbody from a friend tonight. it has the 3.0, 5spd and is 4wd. i'm having some problems with the truck and i'm wondering where to start. my buddy was off roading in the truck and submerged it in water just past the bottom of the doors. he gave me the truck because it wont start. the engine is not hydrolocked. when you turn the key you can hear a single "click" at the starter. the battery voltage is good, the cables are tight, and the starter relay on the passenger side fenderwell clicks once when the key is turned. my friend tried tow starting it and the engine would turn but not start. i know i will need to check the connections at the starter and possibly the starter itself. is there anything else i should be checking for or are there any common problems associated with this condition? 

also, if someone could post a link to the fsm for this particular truck i'd really appreciate it.


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## SPEEDO (Jun 9, 2003)

there should be a blue relay (2 separate plug ins) on the right side of the engine bay.
have someone tap on it while you turn the key to the start position, if its (relay) not totaly fried, it should turn the engine over, I think the relay runs about $10-$15.


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## 88pathoffroad (Jun 6, 2004)

If he sank it deep enough, the ECU is likely fried. It's under your passenger side seat. There's no such thing as an electronic copy of the FSM for 87-93, sorry.


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## mazdaverx7 (Dec 20, 2005)

thats possible because there was water on the floor in the passenger compartment. how primitive is this fuel injection system and ecu? 

the starter not turning is the only problem i am experiencing at this current time. all other gauges other than the tach work(however, i tried flat towing it and letting the clutch out in 2nd gear with the key in the accesory position, engine would turn but not run through all five gears).


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## mazdaverx7 (Dec 20, 2005)

also, what are some symptoms of ecu failure in the HB?


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## mazdaverx7 (Dec 20, 2005)

finally, before i forget, where are the fusible links located?


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## smj999smj (Jan 1, 2006)

The fusible links are at the positive battery cable connection to the battery. Try cranking the engine by using a remote starter to the starter solenoid. If it doesn't crank, you probably need a new starter. If it does, check the 10AMP starter fuse in the fuse block in the driver's compartment. If that's good, go to the "interlock relay" located at the right side engine bay close to the battery (as stated in another post, it looks like a blue relay with two harness connectors). Each connector should have a B/Y wire with battery voltage supplied from the ignition switch when the ignition switch is in the "START" position. If no power, check the fusible link (need power to the W/B wire out of the link, which goes to the ignition switch). If the link is good and power is geting to the W/B wire, check for power to the W/B wire at the ignition switch and the ignition switch, itself. Once you have power to the two wires at the interlock relay when ignition switch is turned to "START," move to the next test:

Find the connector of the interlock relay that has a B/Y and B/P wire. Jumping those wires should cause the starter to crank (make sure you're in neutral!). If not, you need to repair that circuit of the B/P wire to the starter solenoid. If it cranks, move to the next test:

Go to the clutch interlock switch at the clutch pedal. Jump it and see if it starts. If it starts jumped but not with the switch connected, there is a problem with the switch. If it doesn't start jumped:

Clutch switch should have a LG and a B wire. Black wire should have good continuity to ground. The LG wire goes back to the interlock relay. When the key is turned to "START," power at the interlock relay B/Y wire will go through the solenoid of the interlock relay and exits to the LG wire, providing power to the clutch switch. So, if there's no power to the L/G wire at the clutch switch, either the solenoid is "open" in the interlock relay (meaning you need a new relay) or the L/G wire is open or shorted between the interlock relay and the clutch switch; repair the circuit.

As mentioned earlier, you may want to try tapping on the interlock relay first as they do have a tendancy to stick. It may save you some diagnostic time. Since you say you have a "click" sound at the starter, it sounds like the problem area is probably at the starter itself.

As far as your question regarding how "primitive" the fuel injection system is, I guess that depends on what you consider "primitive." It's a typical Bosch style, TBI system: 2 injectors get fed constant battery power and the ECM pulses the ground circuit causing the injectors to fire. ECM gets its referance from the crank position sensor inside the distributor. ECM has 5 mode diagnostic capabilities using a mode selector and a green and red LED. When it came out in 86, it was "state of the art." Since you know the ECM may have been exposed to water, I would remove the passenger seat to access it and remove it from the vehicle. You can remove the Philips head screws to open up the ECM and inspect the circuitboard for signs of corrosion or melting; if either exists, replace the ECM. ECM failure can result in many differant symptoms.


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## mazdaverx7 (Dec 20, 2005)

thank you for the detailed reply!! i will start checking the starter circuit tomorrow and verify my problem areas. as a note, there does not seem to be a clutch start switch or it has already been jumped/bypassed as i can turn the key to start teh engine with my foot on the clutch and with my foot off of the clutch and the results are teh same mechanical click at the starter. as for the fuel injection system, i think after looking at it today and after reading your post, i think its a well designed system. i'm just looking forward to getting this truck on the road and driving it. the previous owners abused it and did not maintain it very well and i'm looking to change that. i keep all 9 of my other cars in excellent working order and this truck will be no different. 
i looked under the passenger portion of the bench seat to see if i could locate the ecu and i saw what appeared to be a black plastic cover over it. it did not look as if water had made it up that far. if you want i can take some pics tomorrow morning when i get off of work and post them up for everyone to see.


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## smj999smj (Jan 1, 2006)

Yes, the ECU came with the plastic cover to protect it.

Sounds like the clutch switch was bypassed. Kind of unnecessary due to the interlock switch on the dash, used to override the switch.


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## mazdaverx7 (Dec 20, 2005)

i thought the same thing. the interlock switch on the dash is a neat feature!!! i'll just have to get into this thing after i wake up this afternoon. we've had nothing but rain for the past few day, making it hard to work on the truck. my 10th Anniversary RX-7 is hogging the garage, lol. i'll just suck it up and go out there tomorrow and get my hands dirty.


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## mazdaverx7 (Dec 20, 2005)

the starter realy is working properly. any tips on how to remove the starter? it looks a little tricky to do and someone with experience i'm hoping will share some tips on how to remove the beast ....


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## smj999smj (Jan 1, 2006)

Yeah, it's a pain....especially if it's all covered in sludge as it gets soaked in oil at every oil filter change! You need to drop the steering linkage out of the way and pull it through to the front. It's easier on a stick because an AT model has metal cooler lines that you have to fight with to get it out!


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