420A 420a Crank-No start

[Zen Hakuren]

History: The engine was running rough after an aftermarket FPR was installed with an evap code P1494. Engine was pulled and timing belt, oil pan seal, oil, oil filter and valve cover seal was replaced. FPR was swapped to the end of the fuel rail and ran with two connections instead of three. Fuel lines were leak tested thoroughly after installation. Engine was put pack on and reconnected and still had rough idle. Codes P0340 and P0352 thrown for the coil pack and camshaft sensors. Coilpack, sparkplugs, and camshaft sensor replaced.

Now I have no spark after cranking. I reinstalled all of the old parts and then installed new parts one at a time to see if a new part had failed. No start still with all of the old parts installed.

So does anyone have any idea on what could be causing this? It ran before all be it not well but now it won't even start and I have confidence that it is spark as I had a buddy crank the engine with the spark plug wires and spark plugs connected outside the engine.

I don't understand why I don't have spark now....

 

[BLACK'98DSM]

It could be the crankshaft position sensor or the connector. Those are common failure points on the 420A that cause a no spark issue.

 

[Zen Hakuren]

It could be the crankshaft position sensor or the connector. Those are common failure points on the 420A that cause a no spark issue.

The issue with this theory is that the old ones were put back on and still no start. Not even a code.

 

[BLACK'98DSM]

Time to start testing wiring and components. Guess work can be a rabbit hole.

Resolved - 420a no spark

I'm getting no spark 420a. I rebuilt the head and redid the timing, it has brand new starter, alternator, crankshaft sensor, camshaft sensor, new coil pack, spark plugs and wires with new ASD relay as well.Power wire for camshaft and crankshaft wire is both 8.8v and the signal wire is around...

www.dsmtuners.com

 

[Zen Hakuren]

Time to start testing wiring and components. Guess work can be a rabbit hole.

Resolved - 420a no spark

I'm getting no spark 420a. I rebuilt the head and redid the timing, it has brand new starter, alternator, crankshaft sensor, camshaft sensor, new coil pack, spark plugs and wires with new ASD relay as well.Power wire for camshaft and crankshaft wire is both 8.8v and the signal wire is around...

www.dsmtuners.com

Damn, I was really hoping it was a simple forehead slapping obvious mistake on my end. I hate cable checking.

 

[Sirius1995]

It could be the crankshaft position sensor or the connector. Those are common failure points on the 420A that cause a no spark issue.

Crank sensor controls fuel pump, not spark, cam sensor controls ignition.

420a wiring is pretty simple, I think you might have faulty ECM, but trace ignition coil wires to ECM and see that you get continuity from end to end same for cam sensor wires, if those are good, then it's your ECM most likely

 

[BLACK'98DSM]

Crank sensor controls fuel pump, not spark, cam sensor controls ignition.

420a wiring is pretty simple, I think you might have faulty ECM, but trace ignition coil wires to ECM and see that you get continuity from end to end same for cam sensor wires, if those are good, then it's your ECM most likely

This is not correct. Read the FSM. The link I posted above has a thread where you not only agreed with my suggestion for another member to check the crankshaft position sensor for a no spark issue, but also I added pages of the ignition system reference from the FSM.

The crankshaft position sensor controls injector pulse, not fuel pump. It ALSO controls ignition trigger.

If you have a 420A handy, go unplug the crankshaft position sensor and check for spark. You will have none. Now do the same with the crankshaft position sensor, you will still have spark, just heavily retarted timing.

 

[Sirius1995]

This is not correct. Read the FSM.

You know what, I checked schematic diagrams and you're right.

 

[Zen Hakuren]

All right. I have done more testing! And still no start, I tested compression:
200 1
190 2
210 3
190 4
Note that this was done with one of those stupid rubber plug adapters and not a full fitting.

I tested continuity of both coil signals to the PCM. Both of which were present. I replaced the camshaft sensor again just to be sure. I cut my negative for my battery and redid the connection both to the battery and replaced the ground strap as well as checking continuity between the engine, body and the ground near the starter to the battery negative to insure grounding.

I checked the PCM ground pins. They are also fine. I have torqued spark plugs to 20 ft/lbs on each install.

ACC power turns on and my dash lights up. The check engine light flashes on then back off. My oil pressure light comes on until I attempt to start. I can hear the pump priming and it is giving ~60psi on start. I have pulled spark plugs after a few attempts in order to reduce flooding from fuel. Spark plugs have fuel on them when removed.

No codes have been thrown. What signals does the PCM need in order to send coil signals?

 

[Sirius1995]

what year is your dsm?

 

[Zen Hakuren]

what year is your dsm?

It is a 1998

 

[Sirius1995]

It is a 1998

okay, I wanted to make sure you didn't have 2ga, so we can mark that off the list, it is possible that your ECU is dead, is there another one you could try it with? unless you got bad sensors as new which can happen

 

[Zen Hakuren]

okay, I wanted to make sure you didn't have 2ga, so we can mark that off the list, it is possible that your ECU is dead, is there another one you could try it with? unless you got bad sensors as new which can happen

I found the issue... My timing was off by about 16 degrees on the crankshaft. I got it to start and run but it loses fuel pressure very quickly. There are no leaks I can see. . going to check.my injectors next. Thanks for all the help of everyone here.

 

[Sirius1995]

I found the issue... My timing was off by about 16 degrees on the crankshaft. I got it to start and run but it loses fuel pressure very quickly. There are no leaks I can see. . going to check.my injectors next. Thanks for all the help of everyone here.

oh I thought you already checked your timing, that makes sense, probably bad pump, do you have stock fuel pressure regulator?

 

[Zen Hakuren]

oh I thought you already checked your timing, that makes sense, probably bad pump, do you have stock fuel pressure regulator?

I did check my timing when I put the engine back in.... It seems the timing belt tensioner was loose when I checked it again. I have it properly torqued now. As for my fpr I have an aftermarket adjustable one. It is set up after the fuel rail to a return line and is set to 55psi at idle. After starting it I got an evap pump code: P1495. I've had this code before and it has come and gone seemingly at random. It runs really rough and eventually dies even if I use the gas pedal. That and fuel pressure drops when dies.

 

[Sirius1995]

I did check my timing when I put the engine back in.... It seems the timing belt tensioner was loose when I checked it again. I have it properly torqued now. As for my fpr I have an aftermarket adjustable one. It is set up after the fuel rail to a return line and is set to 55psi at idle. After starting it I got an evap pump code: P1495. I've had this code before and it has come and gone seemingly at random. It runs really rough and eventually dies even if I use the gas pedal. That and fuel pressure drops when dies.

Check fuel pump connectors and test the relay

 

[Zen Hakuren]

So the issue is my fuel pressure at idle is correct unless I hit the gas. The fuel pressure then decreases until I hit 20psi then stabilizes and doesn't recover unless I turn the car off fully and then back on. I have been through 3 pumps and 3 different brands of FPRs to fix this issue. I do not understand why the fuel pressure does not recover. The pump can provide the proper pressure at idle but not when revving and doesn't recover back when idling.

 

[dwb]

Have you tried replacing the filter? Do you ever smell raw fuel? Is fuel pump rewired and/or have you checked voltages at the pump?

 

[Zen Hakuren]

Have you tried replacing the filter? Do you ever smell raw fuel? Is fuel pump rewired and/or have you checked voltages at the pump?

The filter was replaced as well. I haven't checked voltage at the pump yet. The pump has not been required. The relay was even replaced.

Also I posted that in a new thread because it does run now after several fixes including re looking at the vacuum lines.

 

[steve]

Those threads have been merged, the background is important since you have been having various issues with the car and your current issues might not be unrelated.

 

[Zen Hakuren]

How would I go about checking voltage when the only time this happens is when revving......

 

[Fernanfloo__24]

I did check my timing when I put the engine back in.... It seems the timing belt tensioner was loose when I checked it again. I have it properly torqued now. As for my fpr I have an aftermarket adjustable one. It is set up after the fuel rail to a return line and is set to 55psi at idle. After starting it I got an evap pump code: P1495. I've had this code before and it has come and gone seemingly at random. It runs really rough and eventually dies even if I use the gas pedal. That and fuel pressure drops when dies.

But with the timing wrong the car didn't spark? Or it didn't spark bc of the fpr that was low on psi? I'm having the same issue but mine is all stock l. Just don't have spark

 

[Zen Hakuren]

But with the timing wrong the car didn't spark? Or it didn't spark bc of the fpr that was low on psi? I'm having the same issue but mine is all stock l. Just don't have spark

The car is running with a fuel pressure issue. If you would read further down the no start issue was resolved.