dreski fellows

Not gonna go deep into how I acquired this 93 ex coupe with a f20b manual with a pt3 ecu supposedly his p28 was stolen the wiring on this thing looks like they tried to run it by any means necessary I'm wondering what obd1 harness could use aside from a h22a obd1 prelude si harness as they are harder to come by in my local yard

Aradin

Just find a stock Accord harness for your year and modify it to suit. You will have to extend a few wires.

dreski fellows

F20b is dohc vtec has a knock sensor and obd2 I know a chipped p28 can run those things but theres nothing closer to plug n play appreciate the help

Aradin

In situations like this, you convert the engine to OBD1 using an OBD1 distributor and modified/chipped ECU. If you are thinking you convert the vehicle to OBD2 to match the engine, this is realistically unfeasible. The easiest way is just what I said earlier, get a harness for your year vehicle and do the slight modifications required for it to work with the engine. Generally, you will not use the knock sensor. You CAN if you source an OBD1 P13 ECU, which are extremely rare nowadays. I wouldn't recommend that anyway because the fuel tables will be different and it won't run the engine 100% correctly. It'll be rich everywhere. The best solution is to use a chipped OBD1 ecu and have it tuned to suit your setup. There is no plug and play ECU for your situation that will work without tuning.

dreski fellows

Sounds like a plan while I have you for a moment 93 ex should be internal coil right this is wired for external on the pt3 intake manifold looks like a p13 injectors are spliced so I'm assuming the injectors are factory f20b injectors any other identifiers of h22a dizzy vs f20b

Aradin

You can use internal or external coil with some minor changes but it's easier to just get whatever distributor matches your harness. There are both internal and external coil OBD1 H series distributors available online. The distributors have a stamp in the casting with a TD-xx identifier so you can tell what it is.

If it's running on the PT3 ecu then they probably swapped the injectors to the Accord 240cc injectors. The OBD1 H22 345cc injectors are very rare and would result in the engine running extremely rich when paired with that ECU. Factory F20B injectors have a slimmer body than OBD1 injectors and they are high impedance so the injector resistor box would be deleted.

dreski fellows

Update never actually got it to run on the pt3. Gotta used p28 with a gsr basemap no start haven't gotten into the diag yet but facts now are

Obd1 chipped p28 gsr basemap
Unknown injectors bypassed resistor box
External coil assuming f20b dizzy will confirm
fuel pump on switch as car is stuck in accessory????

Cranks good and i have fuel cant check spark yet need a bud to come assist noticing other wiring issues.

Not expecting much outta the wrong map but I should be able to get an idle and start outta that map right



Ordering a basemap in a week or two
Impossible to find a anything honda obd1 at my local yards


Thoughts on the budget d/b harness on ebay. Thanx again man

dreski fellows

Couldn't find any td number on dizzy called salvo for some differences apparently a 97 accord would use some thing similar to what I have based on manufacturer (opened mine up has tec parts inside...tec and Hitachi were only brand listing differences to source part through them as far as usdm options cb7 nor any prelude has those options from our discussion) but good news is external coil sparks trying a cap and rotor tommarow hopefully somebody needs that dizzy info or can verify it



wiring isn't as bad as initially thought just vtec wires added and resistor bypassed maybe f20 injectors. Per my research on flow types resistor box isn't needed on f20. Love the input when I can get it folks

dreski fellows

Lastly not clear for sure on manifold top half looks like p13 from casting marks anyway to identify the bottom 3 wire map sensor on throttle stuck in accessory is an ignition switch its on the fix list lol

Aradin

I already gave you the answers to most of this stuff but let me get my spoon out again.

Those cheap harness will not work with your chassis for a multitude of reasons. Simple as that. If the car already has an engine harness then you already have what you need. You just need to extend a few connectors. It's not difficult, and it sounds like it was probably already done for you. Your only other option would be to call up Rywire or another custom harness maker and pay big $$$ for a custom engine harness to fit your chassis.

If the injectors are thin bodied, with the resistor box deleted, they are probably the stock F20B/OBD2 Prelude 290cc high impedance injectors. Accord/Prelude 240cc were low impedance and fat bodied. OBD1 H22 345cc injectors are fat bodied and were also low impedance. If you are still unsure just look at the plugs. If they are OBD2 style injector plugs then you have the OBD2 290cc injectors.

External coil OBD1 H22/F20B/etc uses TD-61U distributor. They are available NEW right here.

GSR baesmap will run the car horribly. You need something properly scaled. You can use an H22 basemap with the correct injector information but it will be rich. Most places are hesitant to sell basemaps nowadays. You will need a TUNE to get the most out of the setup and for it to operate safely and properly. Running the car WITHOUT A REAL, PROFESSIONAL DYNO TUNE can result in DESTROYING THE ENGINE in a very short time frame.