89is wont start $50 to the person who figures it out

[GrimmSpeed]

Hey guys,

I've been trouble shooting a no start issue for a few weeks and i can't get it figure out. The car is an 85e with an 89is motor swap. I've checked fuel pressure, replaced the regulator, replaced plugs(has spark), checked grounds, replaced main/fuel relays, checked all fuses, cleaned/checked TPS, checked the CPS, tried a known working ecu. Has new IM gasket and intake boot, no intake leaks. Just did the timing belt/accessories and nothing was off.

The car suddenly died on me after adjusting the valves and replacing the intake manifold gasket. After the work it idled for a few minutes and drove with no issues until it died a few blocks down the road. It was able to start a few random times but will die as soon as gas is applied. It hasn't started for about 2 weeks now.

If anyone can lead me to the answer I would gladly send $50 to your paypal. At this point i have it narrowed down to an electrical issue but don't really know where to go. I have a multimeter and tons of tools so get me to work!

Thank you,

Mike

[slammin.e28]

So, did you use the '89 engine harness, or did you use the '85 engine harness?

[homegrone30]

Abs overvoltage protection relay. (sounds stupid right?) Drivers side dash clipped to the top what I beleive is the abs module. Its an oversized relay. Pull the cover and see if the jumper link is still good.

[jink0619]

Get a new Crank sensor

[GrimmSpeed]

I didn't do the swap so i can't say for sure which harness was used (i'm guessing it still has the 85). It has a 173 ecu and i tested a 380. I tested the crank sensor and it came back at 540 ohms, car also has good spark so i don't think thats it.

I will check the relay on lunch!

Mike

[110stx]

1) Condition of the sensor wiring that threads across the front of the engine behind the pulleys?

2) Condition of the big electrical connector beneath the intake manifold where the injector harness hooks into the main harness?

3) Fuel pump?

[GrimmSpeed]

1) Condition of the sensor wiring that threads across the front of the engine behind the pulleys?

is this the CPS? i did check this and it came back good

2) Condition of the big electrical connector beneath the intake manifold where the injector harness hooks into the main harness?

Did check this and all looked good, also cleaned with electrical parts cleaner.

3) Fuel pump?

Fuel pressure is solid at 45psi

Mike

[slammin.e28]

It was able to start a few random times but will die as soon as gas is applied.

Did you change the fuel filter and verify both pumps were working?

Sounds like when you hit the gas it leans out.

Scenario: You have an old fuel filter. Car will idle fine. You hit the gas, the shit in the fuel filter float up from the bottom of it and clogs the filter so the engine isn't receiving enough gas. You let the car sit for a bit, the shit settles back down. This will also cause the fuel pump to overheat and cut out, as it's trying to pump through a clog. Eventually the pump will quit, and not come back on. This is when you realize you should have put a new $20 filter on.

Just throwing that out there.

[slammin.e28]

Fuel pressure is solid at 45psi

Mike

Solid all the time, or just at idle?

[GrimmSpeed]

I've only been able to test the pressure while cranking since it hasn't started in a while. I've been replacing anything i can anyway so i'll grab a new filter today!

Mike

[paperplane94]

How is the cap and rotor, something tells me ignition.

[slammin.e28]

I had that happen with both my e28 and dad's e30. Figure it's worth a try.

[GrimmSpeed]

I looked at the cap and rotor when i did the timing and didn't notice anything wrong. Is there a way to test it? new fuel filter is on order and i should have it installed tonight.

Mike

[slammin.e28]

I looked at the cap and rotor when i did the timing and didn't notice anything wrong. Is there a way to test it?

Pretty much just a visual inspection. If you're getting spark, it's fine. Make sure the spark is a nice strong blue spark. I had my e28 getting spark, but it was so weak the car wouldn't start, but technically....it WAS getting spark.....

[homegrone30]

If it has spark disregard the relay.