hello everyone i recently replaced my lb9 with an l98, replaced all sensors from knock to esc, replaced timing gear/chain, got a tune from tuned performance. im running open header with hooker 2460's
the engine doesn't sound right to me, i was hopping someone here could give me there 2 cent? i was thinking it might just need a valve adjustment but im not sure. also oil pressure reads way past my stock 60 psi gauge, im not sure if that due to the new pressure sensor being faulty or if the l98 i installed had a high pressure pump on it. engine is throwing a code 43 and a code 15. im also unaware if the installed icm is correct, it came with a distributor i picked up and looked identical to the old one aside form the color, i didnt take it off because i couldnt find any thermal paste.

 

Actually sounds OK to me. I just finished swapping a LB9 for an L98 and they are identical in every way.

If you put in a different oil pressure sensor it could be the wrong one. You need to use the one correct for your year of car, not the one that comes on the engine you put in. I installed a 1988 L98 sender in my 89 car and my oil pressure gauge went past maximum until I put in the correct, 1989 sender unit. The 89 is a three wire, the 88 was a two wire.

Your ICM is probably fine- they usually work or they don't- but I think the knock sensor and ESC need to be compatible.

Where did you get this engine? Used? New rebuild?

Also, did you get a custom tune from Brian? That is worth every penny and your engine will love you when you get finished.

Also, what MAF are you using? Bosch?


43 is the ESC
15 is Coolant Temp Sensor for the ECM it's under the driver's side exhaust manifold. Without this working right, the engine will not run well.

 

These will help:

 

thanks for your input!

The oil sensor is for an 87 350. My car is an 87. Maybe switching to a new 305 sensor will fix that?

I bought the engine used. I heard a video of it running right before it was pulled and it sounded good. I didn’t rebuild it but I did remove the heads and timing chain/gear. I installed new gaskets and timing gear/chain

because I’m running the 350 with a T5 I got the custom tune from tuned performance, who I believe is Brian.

maf is Bosch I believe

if I’m not mistaken my coolant temp sensor is a one wire sensor that slides over a lip on the driver side towards the front of the engine.

also esc is a brand new 350 one for an 87 camaro

 

Not sure about the 1987 harness. I think the oil pressure senders were up on top behind the intake manifold (two wires) on those and the fuel pump switch was down below by the oil filter (two wires). In 89 they combined them into one unit with three wires down by the oil filter. The units look similar and plug in.

By custom tune I mean you collect a data log for Brian, driving around for several minutes, e-mail it to him and he sends you a revised EEPROM based on that data and then you do it again until everything comes in perfect. I'm not sure he does it that way but if he does that's the best. He can see what's happening from the data log.

Yep, that's the coolant senor for the ECM. That's the one that code is talking about.

 

address the code 15 first . That will really effect running should be real rich because of it.

 

after doing a bit more research i think i know what the code 15 issues is. my original motor had the coolant temp sensor for ecu in front of the intake manifold, i still have the wiring for this, a 2 wire connector. the gauge sensor has the single wire that goes in between cylinders 1 and 3. the motor have in it now does not have that front sensor, doesn't even have a spot for it.

can i run that 2 wire connector to a new 2 wire sensor put between cylinders 1 and 3 and splice in the 3rd wire for the temp guage?

 

Post a picture of the intake. Should have provisions for cts . Slp never made a base except the t ram.
edelbrock, tpis, Accel stock base all have provisions for the cts.

 

Maybe its the other way around? I can't recall. 2-wire gauge sensor is off the front of the intake manifold. ECM single wire temp sensor is under exhaust manifold. I dunno. I could never keep it straight. Too lazy to look it up right now.

 

Your intake should look like this. The image on the left is incorrect the cts goes under the coolant hose nipple. There were two connectors on 86-88 one the outer hole. For ninth injector timer switch which you do not need.

 

So the GAUGE sensor is the single wire under the exhaust manifold. The ECM's sensor is the two-wire at the front of the intake manifold. You are correct. Get that one working and get rid of that Code 15 before the other code.

 

i went to look at the car today and found that the sensor was relocated like the second lower manifold in your picture. I hooked it up and started the car no codes came on. I can’t believe I missed that sensor I have no idea how I missed it! Thank you everyone!

But how does the temp sensor not being plugged in cause the knock sensor to read wrong

 

The knock sensor might be incorrect. You can ohm at the at esc module unplug and measure from d to e.
if correct knock sensor should be 100k.

 

hello sorry it took so long for a response, after I hooked up the coolant temp sensor both codes went away. I have now learned that I did not install the second oil pressure sensor behind the distributor and this is why my oil pressure is well above the max all the time. Thank you all for the help