98 sierra 2500 gets gas and spark but won't start

[Klturi421]

Yesterday the truck was running great. No problems. No codes. Now I go to start it up and it cranks but won't start. I can hear he fuel pump priming. A code did pop up and checked. Turned out to be a p0102. Would a maf cause the truck to not start?

Any ideas I can check on? If it were a distributor cap/rotor issue would there still be a spark? Any way to check the timing on it?

As a weather condition it is wet out side if that helps at all.

Thanks in advance!

 

[Molson02536]

Yesterday the truck was running great. No problems. No codes. Now I go to start it up and it cranks but won't start. I can hear he fuel pump priming. A code did pop up and checked. Turned out to be a p0102. Would a maf cause the truck to not start?

Any ideas I can check on? If it were a distributor cap/rotor issue would there still be a spark? Any way to check the timing on it?

As a weather condition it is wet out side if that helps at all.

Thanks in advance!

Start with the simple and check your fuses. The wiring harness by the firewall over the transmission, its the sensor side of the O2 sensor (not the heat side) may have a shorted wire which will caused the ENG-1 fuse to blow.

Start with that and keep us posted and repair any damaged wire harness.

Molson02536

 

[Klturi421]

Wiring was checked as well as the fuses. Those check out just fine. No issues there. One thing that I was going to check was the fuel pump. For some reason it struck me last night that it might be a fuel delivery issue. The pump itself is priming but may not actually be sending fuel.

Yesterday my brother in law replaced the u-joints on the drive shaft, so I am wondering if maybe he hit anything, he says that he didn't. Could even be the fuel pump. Happened on my s10 blazer.

Any idea where I should check the fuel pressure at? The fuel line at the back of the engine seems to be a little difficult to reach. Was looking at checking near the fuel filter. Any Ideas?

 

[Molson02536]

Wiring was checked as well as the fuses. Those check out just fine. No issues there. One thing that I was going to check was the fuel pump. For some reason it struck me last night that it might be a fuel delivery issue. The pump itself is priming but may not actually be sending fuel.

Yesterday my brother in law replaced the u-joints on the drive shaft, so I am wondering if maybe he hit anything, he says that he didn't. Could even be the fuel pump. Happened on my s10 blazer.

Any idea where I should check the fuel pressure at? The fuel line at the back of the engine seems to be a little difficult to reach. Was looking at checking near the fuel filter. Any Ideas?

You can check your fuel pressure with a gas pressure gauge connected to the schrader valve located on the fuel line by the distributor on the drivers side. You need 62-65 psi to get the engine started and should drop by 5 psi when the engine is running.

You can start with the simple and spray a small amount o enginef starter fluid into the throttle body and see if the engine will start and stay running.

If so, then its your fuel system that's has the issue and you my need a new fuel sending unit. If it doesn't start, that its going to be your ignition system that will need to be address and I would start with having the ICM tested.

Keep us posted.

Molson02536

 

[Klturi421]

One thing that I did last night, haven't worked on it today, was sprayed some starter fluid into the air breather just before the MAF, the filter was off when I sprayed it in and it would start or even act like it wanted to start with it. Would I need to spray it directly into the throttle body?

 

[Molson02536]

One thing that I did last night, haven't worked on it today, was sprayed some starter fluid into the air breather just before the MAF, the filter was off when I sprayed it in and it would start or even act like it wanted to start with it. Would I need to spray it directly into the throttle body?

It should of stared or tried to start when the starter fluid vapors made its way into your intake. I would make sure that your ignition system is working and your have a good spark at the plugs.

Check the wire harness to your coil and ICM to make sure no crazy animals like a field mouse didn't chew the wires off trying to make a winter nest for him self somewhere lol.

If all wires look good, then have the ICM tested at Napa or another brand auto parts store and they can check it for buy before you buy a new one.

Keep us posted

Molson02536

 

[PSEUDONYM]

I had the same issue on a 2001 Chevy Express 5.7 liter. It would start when I sprayed starting fluid directly into the throttle body, but power was down. The issue was the SCFI system. It did not show any codes. I converted to MFI with AC Delco part #2173029, now everything works fine.