2G Crank but no start

[alexis4g63t]

i am currently trying to figure out what's causing a crank and no start i have recently replaced the MPI, Fuel Pump, PTU, Coil Pack connector, and i had a local shop put in a new water pump and oil pump I redid the rod bearings, resealed the oil pan etc etc. when i replaced both the MPI and Fuel Pump the car started but immediately died off and would just crank i am no longer hearing the fuel pump hum so something is just cutting the signal to the fuel pump or something. i am currently thinking its the ECU but if anyone has an idea of what could be happening let me know

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[pauleyman]

Your profile says no mods?
What did you diagnose? Putting a new part on is not diagnosis. What did you test? Fuel? Spark? Compression? Mechanical timing?

Does CEL light come on with key on?

Try this link.

How To Diagnose A No-Start

Diagnosing a No-StartI've been seeing a lot of No-Start related threads popping up lately, and I figured a basic Tech Article for diagnosing a few of the most common No-Start problems might be in order. Any images posted are courtesy of my 1990 GSX your setup may differ slightly; refer to...

www.dsmtuners.com

 

[alexis4g63t]

It's mostly stock, just some feel better mods. Fuel is not coming out of the fuel rail as well I am not hearing the fuel pump hum at all. Compression is fine, I've redone the timing at least 6 times and I'm not sure what the ECU light would look like. Spark would be present but I think something is just shutting it out.

The car was running and driving fine before it just suddenly would not stay on. I tried cranking it back on but nothing. Could it be even low radiator fluid or the sensor being unplugged causing a no start?

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[pauleyman]

its mostly stock just some feel better mods, fuel is not coming out of the fuel rail as well i am not hearing the fuel pump hum at all, compression is fine, ive redone the timing at least 6 times , and im not sure what the ecu light would look like, spark would be present but i think something is just shutting it out. but the car was running and driving fine before it just suddenly would not stay on i tried cranking it back on but nothing. could it be even low radiator fluid or the sensor being unplugged causing a no start?

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Check engine light. Should come on and go off in 5 sec.

Was it running before the shop took posession?

 

[99dsmer4g63]

The coolant sensor being unplugged would cause a no start. You mentioned the plug being unplugged.

Use the fuel pump check connector and see if the pump turns on. Says you have a 95 so you should have one in the firewall.

-Daniel

 

[alexis4g63t]

Check engine light. Should come on and go off in 5 sec.

Was it running before the shop took posession?

check engine light does go off after 5 seconds and yes it was running before i took it to the shop

The coolant sensor being unplugged would cause a no start. You mentioned the plug being unplugged.

Use the fuel pump check connector and see if the pump turns on. Says you have a 95 so you should have one in the firewall.

-Daniel

just ordered a new temp sensor connector as the one on the car r literal wires just loosely hanging around, got no idea how this thing ran multiple times but im glad i got the heat cycle in for the new rod bearings in time . i will update this post when i fix the coolant temp sensor hopefully that is what is causing the crank but no start issue.

 

[pauleyman]

just ordered a new temp sensor connector as the one on the car r literal wires just loosely hanging around, got no idea how this thing ran multiple times but im glad i got the heat cycle in for the new rod bearings in time . i will update this post when i fix the coolant temp sensor hopefully that is what is causing the crank but no start issue.

Do you have any way to datalog? Cheap 25$ setup would show you some sensor values etc.

 

[alexis4g63t]

i got some cheap innova 3011rs that supposed to have live data but its just not showing me it for some reason? idk could be that they don't support older cars or sum. and unfortunately, the new coolant temp sensor did not work

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[alexis4g63t]

UPDATE, so I got evoscan and a USB to OBD 2 port, changed some settings for a 2g. And it is indeed a fuel related issue.

I'm seeing crank, TPS, CTP, MAS, O2 and injector pulse width. I'm certain its something to do with the fuel pump wiring tho, when I pulled it out it seemed fine but I guess it's something in there that's messed up.

And yes I sprayed starter fluid and it did try to start. I'm also gunna replace the fuel filter just while I'm in there.

 

[pauleyman]

UPDATE, so I got evoscan and a USB to OBD 2 port, changed some settings for a 2g. And it is indeed a fuel related issue.

I'm seeing crank, TPS, CTP, MAS, O2 and injector pulse width. I'm certain its something to do with the fuel pump wiring tho, when I pulled it out it seemed fine but I guess it's something in there that's messed up.

And yes I sprayed starter fluid and it did try to start. I'm also gunna replace the fuel filter just while I'm in there.

You can manually jump the fuel pump at the check connector on the firewall and rule out most of the circuit without the car even running. Allows you to check the relay, wiring, pump etc by just listening and a voltmeter. You can also physically check fuel flow through the rail.

Nice and safe without a running car.

 

[alexis4g63t]

Ok, I ended up doing what legitstreetcars did with his fuel pump because the connectors at the actual fuel pump itself were bad, so I made a hole on the pump assembly ran the wires through put ground and power from my ignition switch. The new problem is keeping the car on, it'll start but won't stay on. It will sputter then die out, what do I do now?

Could be MAF or can it be low voltage after it starts?

 

[luv2rallye]

Have you ever checked fuel rail fuel pressure? If not sufficient it will do exactly as you describe. Example: A leaky fuel pressure regulator (on drivers side of fuel rail) could be leaking all the pressure back to the tank giving these symptoms. Also normal fuel pressure should remain for days after engine is turned off.

 

[alexis4g63t]

Have you ever checked fuel rail fuel pressure? If not sufficient it will do exactly as you describe. Example: A leaky fuel pressure regulator (on drivers side of fuel rail) could be leaking all the pressure back to the tank giving these symptoms. Also normal fuel pressure should remain for days after engine is turned off.

no i didnt check but i did use a scanner and it gave me a P0100 code the MAF sensor is bad, im getting a new one from PR i will update this again when i come back with the new maf

 

[luv2rallye]

If the new MAF doesn't fix it check the fuel pressure as it won't give you a CEL code.

 

[pauleyman]

no i didnt check but i did use a scanner and it gave me a P0100 code the MAF sensor is bad, im getting a new one from PR i will update this again when i come back with the new maf

Just for reference getting a code doesnt mean a part is bad. It just means there is a problem with that circuit. Its up to you to go look at the components, wiring, connectors etc. I say this because in 30 years ive never had one go bad.

 

[luv2rallye]

Ya I've never had a MAF go bad either and new ones are very pricey.

 

[alexis4g63t]

Just for reference getting a code doesnt mean a part is bad. It just means there is a problem with that circuit. Its up to you to go look at the components, wiring, connectors etc. I say this because in 30 years ive never had one go bad.

could be possible since it was just working fine but a buddy of mine had the same issue so it's not totally out of the question, when i get the new maf and its still doing the same thing ill dig deeper into the connectors etc etc. and yea new ones are pricey but this is from his old setup and he isn't going to be running it anymore so he's just tossing it in for me free of charge

 

[alexis4g63t]

UPDATE, Hey just got back from PR yesterday put in the new MAF and the code went away but the car still didn't stay on.

Well, this morning I was checking to see if I was using the correct ignition wire and it turns out I wasn't. It was indeed the black with white stripe wire, and the car started right up no issues. I was using a black wire with red stripe thus causing the start but not fully staying on.

I want to thank everyone for giving me pointers and genuine advice it truly did help me out you got no idea! I still got more work to do but at least I can drive the car now :3