Engine no start, no check engine light on?

If fuel pump is not energizing when key is on and pump is new, check fuel pump relay. When ign. is turned on, FP relay should click, if not then relay or fuse.

When you turn the key to the on position without cranking the engine over can you hear the fuel pump run in the tank for 5 seconds?

https://www.2carpros.com/articles/car-cranks-but-wont-start

Please run down this guide and report back.

If relay and fuse are OK, then it may be a wiring issue, the wiring/ground to the FP.

Start by checking fuel pressure with a mechanical gauge, if no fuel pressure, then fuel issue.
If no gauge is available, spray some starting fluid into throttle body, if car runs for a few seconds, it is the fuel system.

we know that the original problem was the relay but now it won't start at all. do we need to just replace the fuel pump?

https://www.2carpros.com/articles/car-cranks-but-wont-start

Get a helper disconnect a sparkplug wire or 2 and ground it to the engine atleast 3/16 away from ground-have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, Do you hear the fuel pump come On when you turn key on? If not check fuel pump fuse and fuel pump relay if okay-check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs,coil's resistances,cap and rotor,distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it and keep testing

Have you checked to see if your getting power and ground to the fuel pump while your cranking the engine to start it?

1997 Chevy Mark III Van
90,000 miles
305 Cu in

My van was running fine till the other day.
Now when I try to start it, it wont start unless I give a shot of ether. It then starts right up and runs fine.

I can then shut it off and it will start right back up. But, if I let it sit a while, it will just crank over and not start unless I give another shot of ether.

I can also hear the fuel pump build pressure and stop.


Any ideas?

Check the fuel system residual pressure-hook up a fuel pressure gauge and time it 5-10mins. it should hold the specified pressure if it drops quick-check the fuel pressure regulator/injector/pump check valve your leaking pressure.

Electrical problem
1997 Chevy Van V8 Two Wheel Drive Automatic ? miles

I have a Chevy 2500 Van with a 5.7L engine that cranks but not start. I confirmed spark and compression. I found no power to the fuel pump and had no pressure (obviously), I measured the voltage at the fuel pump relay found 12v on pin 87 (Org/B1), I have 0v on pin 86 (Green/White wire) the Fuel Pump Relay Feed from the VCM. I have good grounds at the relay. I tried jumping 12v battery power to 87a (GRY/A3) wasn't able to confirm fuel flow from the pump (I couldn't hear it pumping). I did test the relay and all checked out. Any ideas I still have to look at the oil pressure sender. Until tonight when I have the proper tools to get to it.
Any ideas???

Power the fuel pump connector gray wire from the battery, did the fuel pump come on?

I could not confirm the pump at that time. I tried to start the vehicle and it wouldn't. Going to be back at the vehicle later tonight to take the doghouse off. I figure I should've been able to hear the pump. I will repost tonight once I know for sure that the pump wasn't turning on.

[quote:2143e98e37="rasmataz"]Power the fuel pump connector gray wire from the battery, did the fuel pump come on?[/quote:2143e98e37]

Okay, so I made a connection to the fuel pump with a 10 amp jumper wire i made, I confirmed that the voltage is getting to the pump. I had the fuel filter lines disconnected when I energized the circuit and to no avail I had no fuel flow... I confirmed the ground which had 3-4 ohms of resistance. Also confirmed the 2 sec feed from the ECM/VCM. So I'm thinking I should possibly be replacing the pump. But I would like a second opinion, there is still something in the back of my head thinking that the oil pressure sender could be causing this. But after jumper`n the fuel pump and not getting anything, ARGG. I would just like to be sure in my head. I'm thinking too much.

You got battery voltage and a good ground it should fire up w/o the oil pressure switch when direct battery voltage being applied

[quote:52045c662a="rasmataz"]You got battery voltage and a good ground it should fire up w/o the oil pressure switch when direct battery voltage being applied[/quote:52045c662a]

That is what I thought or at least puymp fuel all over the ground which it didn't do that either. I guess I just didn't wish the pump to be bad @ $528+tax. Thanks for helping.

My van will not start in the mornings or if it sit for more than 2 hours the only way that I can get it to start is if I use staring fluid

check fuel pressure and let me know what do you have for pressure

[quote:68129bedf3="charmed1"]Engine Mechanical problem
1997 Chevy Van V8 Four Wheel Drive Automatic 109000 miles

My van will not start in the mornings or if it sit for more than 2 hours the only way that I can get it to start is if I use staring fluid[/quote:68129bedf3]

When was the last time your vehicle had any induction services?

I have a 19997 Chevy Conversion van with approx. 171,000. Runs great, however when it rains or a dew/heavy humidity occur, it will not fire. suspect electrical. I have taken to 3 shops. Once I was able to start drove to Chevy dealer, they put on dyno, no problem found. Twice had towed however both times whe shops were able to look at vehicle , it started. No problem found. As you can see it usally starts after 2 to 3 hours moisture leaves area I have got no suggestions from any trust worthy mechanics in K.C. area. Can you help?

i know when i had that problam mine was as simple as a cracked cap when the water got under the cap will not fire untill cap was somewhat dry agin. hopfully that helps

its time for a tune up
replace cap and rotor
check coil and relpace ignition wires too
good luck

Good fuel pressure and good spark. Turns over fine will try to run on starting fluid

scan for codes and check fuel pressure with a gauge 60-66 psi if below that won't run. check fuses underhood box and check pcm connectors for corrosion if they have it,cleanit off and use dielectric grease at connections.

1996 Chevy Van V8 Two Wheel Drive Automatic 137k miles

In the morning, my van turns over but won't start unless I spray a little ether in it. For the rest of the day it starts fine and runs great. I tried adding fuel injector cleaner but it didn't help

Thanks

Assuming you are not getting any error codes, it is a fuel problem.

Best approach is to have the fuel pressure tested with a mechanical gauge.

If OK, then I would suspect the cold start valve. It is a small injector that adds additional fuel on cold engines, it only operates when cranking and if not working will cause the no start (cold) you describe.

I can be driving along fine when suddenly the engine is racing and acting like the transmission doesnt exist. This occurs for a few seconds and then all is fine again. Once when I started the van it died and I had to restart several times and had to increase the RPM to keep it running but when I got on the road the van acted like the trans wasnt even connected. I parked it and the next morning all was fine for about a week and then I had the problem when on the road at high speed but it corrected itself.

Hi there,

Thank you for the donation,

i would first check fore any unresolved fault codes in the ECU, not all fault codes will set a MIL, also as a precaution i would get the transmission in for a test and report at by a qualified trans tech, to be honest, i don't think that i have come across problem like this, it sounds like a sudden drop of line pressure, but some tests may show up more , start here.

mark (mhpautos)

There are no fault codes showing up. Could you get me a second opinion as this is eratic and probably wont happen when it is looked AT

replaced fuel pump,filter,plug wires,dist. cap rotor,cam pos. sensor. engine cranks but will not start. pulled codes found PO306

PO306 is just a misfire on cylinder #6

All "crank, no start" conditions are approached in the same way. Every engine requires certain functions to be able to run. Some of these functions rely on specific components to work and some components are part of more than one function so it is important to see the whole picture to be able to conclude anything about what may have failed. Also, these functions can ONLY be tested during the failure. Any other time and they will simply test good because the problem isn't present at the moment.
If you approach this in any other way, you are merely guessing and that only serves to replace unnecessary parts and wastes money.



Every engine requires spark, fuel and compression to run. That's what we have to look for.

These are the basics that need to be tested and will give us the info required to isolate a cause.

1) Test for spark at the plug end of the wire using a spark tester. If none found, check for power supply on the + terminal of the coil with the key on.


2) Test for injector pulse using a small bulb called a noid light. If none found, check for power supply at one side of the injector with the key on.


3) Use a fuel pressure gauge to test for correct fuel pressure, also noticing if the pressure holds when key is shut off.

4) If all of these things check good, then you would need to do a complete compression test.

Once you have determined which of these functions has dropped out,
you will know which system is having the problem.

Greetings,

I really appreciate your website and making your knowledge and experience available to us shade-tree mechanics.

My problem child is my 1995 Chevy Beauville Van, 5.7 TBI, 4L60E Trans (I think), It’s really in great shape and I plan to repair the rusted lower body panel and make her new again. But she’s currently giving me fits.

I worked on it one evening, installing some fog lights. I ran my fused switch line to the a pin on the fuse block. Job was done, I shut her off, and went in for the night. She would not start the next morning.

The truck has it’s original fuel pump (which I admit still could be the problem if there’s not ENOUGH fuel pressure). However, when I jump the FP Relay, and crack the fittings at the base of the TB, II get a very healthy spray. If I pour raw fuel into the TB, she will light. I don’t have a fuel pressure gage to check, but I believe the pump to be OK.

I have replaced all the fuses and Circuit Breakers. On two occasions the van DID start, but ran very rough. I attribute this to the FP Relay fluttering as I had a test light connected to ground and the relay activation lead. It flashed wildly and pulsed to the engine ignition. Eventually the engine would die, not to start again. This is what leads me to believe that this is an electrical issue.

She turns over freely. No known mechanical issues. I have + power to the injectors but they are not activating that I can tell through my stethoscope (long screwdriver to my ear).

I have swapped the PCM with a known good unit. I have also replaced the FP Relay. If I jump the relay, the pump runs at the same pitch as it always has. Sound just like the one in my 1995 Caprice. Are there any fuseable links or hidden fuses I should be looking for? Everything seems tobe in order under the dash. This has not been all cobbled up like so many old vehicles. It’s all original and in very good shape.

So, assuming there is adequate fuel pressure from the pump, the PCM is good, all the fuses are good, the FP Relay is good, there is good gas in the tank, the battery is strong and connections are clean, what am I missing?

I am hopeful you can help me. My job is depending on this van.
Sincere thanks,

Chris Baker
[email protected]

Check the fuel pressure and get back

FUEL PUMP PERFORMANCE

5.7L (VIN K) 9-13 psi

Will check that tomorrow. However, I feel the pressure is there. Assuming it is, after all of this, what would prevent the FP relay from engaging? It appears (if I got the right wiring diagram) that I'm not getting power to the relay or possibly the PCM, thus preventing the pump from running and the injectors from activating.

BTW, There is good 12VDC + at the injectors. Rechecked all the plugs.

So, if everything else is checking out OK, I guess my question is what would cause the FP relay to flutter? Could the pump put such a drain (dragging) that it would cause the relay to disengage? I would have my doubts, but I'm not the expert.

Thanks guys!
Chris Baker

Its the computer that energizes the fuel pump relay and also drives the ground circuit for the injectors-recommend you check the wiring and also for shorted injector that's taking out the other

OK. But I swapped computers with a known running van of the same year, make and model. My computer runs that van fine.

Pardon my ignorance, but what would then be between (or before) the Computer under the seat and the relay and injectors that could cause this?

i've never seen anything like this. Also, I have great spark from the dist to the plugs.

Thanks for the diagram. Where would that test port be located on my van?

Truly, many thanks for your help.

What type of fuel system do you have? TBI/MPFI/CPI Vortec ????? Not to familiar with vans-If its a vortec-you should be able to see the fuel test port when you follow back to the rear from the upper plenum

It's the last year of the previous generation of full-sized Chevy Van (boxy), So it is TBI--fuel is fed into base of TB and injected thru the 2 injection over the throttle butterfly.

Get helper to crank her over and look at the injectors are they spraying fuel in a cone looking shape-

The fuel lines is behind the TB follow the feed if there's no test port T the fuel filter

Already known. There is no fuel coming out. When I jump the FP relay, the FP runs and sound absoutely normal (I know, not a real indication of performance, but is't a start).

When FP is running, I can crack the fittings at the base of the TB and get a strong spray. What I've narrowed down is that the FP relay is not being activated when KOEO (key on-engine off) position. It should activate for approx 3 seconds as a prime to stat the engine. At this time the engine is supposed to start and the oil pressure sensor tells the PCM to continue pumping fuel. None of that is happening.

Thanks

The computer doesn't control the OPSU-when the computer energizes the relay for 2secs it primes the fuel system-when vehicle starts up the OPSU powers the fuel pump by closing its contacts by oil pressure.

Check the pressure should be 9-13psi

Hi guys, Just got back inside. Very cold and snowing hard here in Northern Indiana. OK. Fuel pressure (if we read the things correctly) indicates just under 12 psi. I figure that should be enough.

So there is still no 2-3 second prime activity or injector pulse. Remember in my earlier posts, I swapped PCM's with a known working vehicle. Could there be a problem in the wiring harness? Any ideas of where I might start looking? BTW, there is no place in any of the looms that indicate melting or tearaway as if being too close to the exhaust of getting snagged on something. Also remember that she ran fine up to the point where I parked her, then she wouldn't start the next morning. Ans also remember the fluttering fo the FP relay when she DID start, but ran rough.

I'm not the dimmest bulb in the box, but I can't figure this one out. I honestly cannot understand what may be casuing this.

Is there anything under the dash, near the fuse panel that could be unplugged or something?

You guys are great. I am very releived to be able to bounce these troubles off of you. Hopefully, we can figure it out.

CB

Remove relay from connecor-check wiring for power

At the fuel pump relay wire harness check for power on the orange wire-you should have it-if the fuel pump fuse is okay-

Now turn key to run you should have power on the dark green and white wire let me know-

Hi Ras, Orange wire is hot. Fuse is good. With the test light on the Green wire, it does NOT come on with key.

The problem has to be AFTER the key and BEFORE the fuel pump. I've just come in after checking EVERY electrical connection on the engine harness.

Also, all the connections under the dash, on the steering column appear to be intact and undamged.

Keep in mind, I have the insode engine cover off and a test light connected to the green lead so I can see if power is going to the FP. Plus, I can also hear the pump if it is running. It is almost as though there is not enough current to keep the relay engaged. I don't see that as possible as the Amp meter shows a positive charge when it did start, plus there is a high-power battery charger or other vehicle jumping it.