What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

199 Suburban V1500 4x4 350 engine tuns over but does not start

B

blackandgold51

1/2 ton status
Joined
Oct 6, 2015
Posts
724
Reaction score
86
Location
New Orleans, LA
I was driving through the parking lot and th suburban just shut off. I cranked it up but no start. I turned the key in ignition and I hear no fuel pump sound.

I"m guess that due to the streets having bumps andpot holes might have knocked the fuel pump loose??
 
Not likely at all.

Check your fuses. Pretty sure you've got a fuel pump one. Take a wire with you, and run it from the battery + terminal to the red wire hanging off the relay on the firewall. That will force the pump to run. If you have another relay, swap it, just in case the relay is bad internally. (I'm not saying replace parts...just if you have a spare relay, try it....the '88+ C/K's used the same relay style for the AC and fuel pumps, so those are easy to swap to test, not sure if the R/V trucks got the same setup) The truck SHOULD still start after about 10 seconds of cranking even with a bad relay, since the oil pressure switch should close, but if it's failed already, it wouldn't start.

Also realize that the pump won't turn on every time you rotate the key to run. There is about a 10-15 second timer in the ECM, you'd have to wait at least that long between each try to actually hear the pump run, if it's working.
 
After fuses and relay checks,I would be looking at the ignition control module,inside the dizzy
 
snowdriver said:
After fuses and relay checks,I would be looking at the ignition control module,inside the dizzy
Click to expand...
Hmmm. Is that one of the reason why the suburban sometimes feel like it's "dragging" and lose power when stepping on the accelerator and then goes back to normal?

I was thinking it was the injectors which I was going top replace later on with high performance injectors. It sometimes felt like a delay in fuel when I step on the throttle
 
Ask here before you go replacing stuff. "High performance" injectors aren't going to do anything, and may make it run worse.

It would be possible the ignition module is dead, but that has no bearing on the fuel pump running in terms of priming with the key. No spark is an easy way to tell the module is toast, but that isn't the only test of it.
 
dyeager535 said:
Ask here before you go replacing stuff. "High performance" injectors aren't going to do anything, and may make it run worse.

It would be possible the ignition module is dead, but that has no bearing on the fuel pump running in terms of priming with the key. No spark is an easy way to tell the module is toast, but that isn't the only test of it.
Click to expand...
How does high performance injectors make it run worse? Along with a high performance throttle body?
 
When my icm went bad,spark was dead,but fuel pump still worked,I have heard when they go bad,you shouldn't be getting fuel either,but mine just killed the spark side
 
Also,hi-perf injectors won't do you any good,unless you have upgraded exhaust,intake,and better flowing heads,,,,
 
snowdriver said:
When my icm went bad,spark was dead,but fuel pump still worked,I have heard when they go bad,you shouldn't be getting fuel either,but mine just killed the spark side
Click to expand...
Where can I locate all the electric stuff (inside the suburban)for the fuel pump? Relays, switches etc?
 
The icm is under the distributor cap,you have a fuel pump relay on the firewall,just to the left of center as you look at the engine,but that relay is just to start the truck,there is also a oil pressure switch that keeps the fuel pump running after start up,I am not sure where that one is,and your fuel pump is inside the tank
 
I've had fuel pump issues on mine before and never had one actually run good and just quit ? Mine would be sluggish and act like it was starving for fuel before it died. I have been in a buddies truck and his died on us we tapped the tank with a rubber mallet and it came back to life long enough to make it home. I had a cts sensor crap out at a red light and it would not crank luckily a empty tow truck was behind me and towed it home where it cranked right up lol. Word to wise if it is a fuel pump change the wiring harness to the module or buy a new module. I burnt up 3 pumps before I changed the module and solved my problems.
 
I'd put a new fuel filter on in before doing anything more labor intensive..it just might be plugged up with crud or water..
 
diesel4me said:
I'd put a new fuel filter on in before doing anything more labor intensive..it just might be plugged up with crud or water..
Click to expand...

I saw the problem a few minutes ago, the fuel relay was hangin on the side of th manifold which probably burnt the relay due to the manifold bein hot.
 
blackandgold51 said:
How does high performance injectors make it run worse? Along with a high performance throttle body?
Click to expand...

You can't just add fuel to an engine and get better performance, UNLESS it has the air to support the additional fuel. EFI (at least EFI without wideband O2's) like your truck has cannot compensate for too much or too little fuel under certain conditions. The engine will run lean or rich under other than cruise conditions, neither of which is good. Obviously running lean, you run the risk of destroying the engine. You change the air or fuel requirements of the engine, you need to tune the vehicle through the PROM.

These engines are "limited" by the cam, heads, probably the intake, and exhaust. In reality they make very good power at the low end, and increasing air/fuel isn't likely going to help under those conditions.

Do people throw "high performance" stuff on the engines and seemingly not have problems? Yes. Does that mean they have done the work and testing to ensure that fueling is right across the board? Nope.
 
You must log in or register to reply here.

Latest Posts

Top Bottom