my son bought a 87 camaro sport original 2.8 car. previous owner put in a 91 5.0 tpi switched it to maf. and has ecu 1227165.
needless to say the wiring is a nightmare of unused sockets and spliced wires. it does run great though

oil pressure guage pegs as soon as i turn the ignition on.
the oil pressure switch is a 3 prong located by oil filter, orange, gray,tan wires.
I removed the tan wire, checked again key on peged then grounded the wire going to the guage and still pegged.
sensor reads 3meg ohm on tan wire to ground.

whats the next step, just got the car so no haynes manual yet because they had to order one and at this point alldata is out cause id have to buy like 3 subscriptions for this vehicle.

 

I don't think you need the manual, you've already got a handle on it.

Oil pressure gauge will peg high with open circuit. Sounds like you already figured out the wire is broken open somewhere. You could take circuit resistance again at the C100 connector on firewall and at least figure out whether the problem is on the interior side or engine bay side. It's hard to find a broken wire inside a wire loom. It might be easier just to lay new wire and bypass the broken section.

 

yeah a background in electronics helps, just wish they would have used the correct harness when they swapped engines, since the kids uncle that did the work owns a repair shop. the kid he bought it from didn't understand why the tach didn't work also, so i explained a v6 has a different signal then a v8.

well i guess tomorrow ill break into the connector and see which side its on.

 

Just an FYI - I'm not sure about Camaro, but the Firebird I know uses different gauge face plates for V6 and V8 , and the sender is calibrated to the faceplate. The gauge internals are the same, but the V6 faceplate goes to higher numbers than the V8 faceplate (for the same sweep).

​​​​​​V8 sender will sweep the needle further across the gauge then a V6 sender at the same pressure. So mixing a V8 sender with a V6 gauge will indicate false higher pressure.

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Regarding shop manual with wiring diagrams, you don't need it for an oil gauge because it's so simple, but you might need it if you keep running into more complex problems.

Haynes and Chilton I consider useless. A proper GM shop manual is a thousand times better and easier to understand the wiring diagrams. There's a guy that posted in the classified section who is selling a bunch of shop manuals for $50 each (which is a steal)

 

Unfortunately, he took down the listing not long after posting, which is a shame.... I was hoping to get another copy of the '92 manual, mine is getting pretty ratty. AustinThirdgen has some good PDFs of factory service manuals, but they don't have a complete collection. Still though, access to at least some of the fac service manuals for free is pretty handy!

 

yeah, i am ordering v6 sensors for the guages, ill have to order a v8 tach though.

 

so took apart the c100. 0.3 ohms from bulkhead to sensor wire. 0.3 from cowl to gauge sensor plugin. 0.6 from ground plugin behind gauge to alternator ( I plan on adding more ground straps)
put the c100 back together 0.4 ohms from sensor wire to gauge pluging.

put it back together and it seems to be working 55 cold 45 warm.

now i noticed the cooling fan isnt turning on....

 

Because the car was 'back-yard-built' there is a lot of combinations possible to get a V6 car wired for a TPI set-up. With any luck; the builder used "compatible" parts. Probably a good idea too figure out EACTLY what your working with !

Engine is from a 91 TPI
Engine is now MAF
V6-V8
Camaro not Firebird

If the engine is built with a serpentine belt system than it's 'most likely' a 88-89 TPI ECM Harness. You can check for a cold start injector to help ID things,.. but it could have been removed from a cold start harness. An 87 MPFI and an 86 or 87 TPI should be very compatible harnesses.

This is an old picture from some work I did awhile back,...... If you find THIS PLUG near the ECM ( under the dash) than the ECM harness that was used came from a 85-87 TPI car. ( Circled in GREEN ! )



This connection is called 'C221' ( circled in GREEN ! ) and it was used from 85-87 for all fuel injected cars. It's usually GREY plug on the engine harness side and BLACK plug on the dash harness side. Here is the wired pin-out for C207 ( circled in BLUE ) and C221 on 86 & 87 cars:
* 85 is similar - but a little different I think ! ( due to MAF Burn-off ? )

Once you figure out exactly what ECM harness was used - the easier it will be to trace down any lingering issues !

 

You need V8 a V8 OP sensor if you've got a V8 engine; you also need a V8 Tach if you have a V8 engine.

There is a specific oil pressure sending unit for V6 cars and V-8 cars. (V6 are 40/80) and V8 are 30/60) You can use the same oil pressure gauge and the reading will be similar due to the similar scaling of 30/60- vs 40/80. The Camaro has a problem here because many Tachometers have a built-in oil pressure gauge ---> and the Tachometer MUST match the engine or the readings will be off 25% ( or is it 33%?)

V6 distributor sends 3 pulses per rev vs the 4 pulses per rev for a V8. You can see how this will cause a conflict when connected to the wrong tachometer. ( This can be overcome with a signal converter. )

If you end up needing a tachometer I should still have a couple hanging around. ID exactly what you have before making any purchases - just to be sure you don't spend needlessly.

 

pretty sure i will need a v-8 tach and i am buying v-6 sensors for the gauges or does that not matter even if the gauges were for a v6
ecu is 1227165
867961 M622512339
16067961
blue and grey connector on it, ill look for the one you mentioned.

still had the 2.8 vap canister in it , no cold start on the fuel rail . harness has extra connectors like on each side it has a connector that looks like the injector connectors that are just laying there not used.
water pump has a top hole that is plugged and the heater core supply is out of the intake, no coolant flows thru the throttle body.temp sensor for fans comes out the front of the intake.

 

tan wire is oil pressure , dunno about the green


supposed to be the ac wiring they cut

cooling fan connectors

 

I still have my 8k rpm V6 tach with a V8. A friend used a signal generator to dial in a V8 calibration by changing a resistor in the tach. Works good, more accurate than stock.