87 5.7 TBI Died

[Sgt Hollywood]

So my 87 Short bed (350 tbi) was running great last week. Then while cruising at 65mph on the highway it lost power, luckily I managed to hit the off ramp on the down side. Having limited tools with me and being 2hours away from home I was a bit in a jam.

Checked the filter and I do get fuel spray from both injectors, but how much is a question. But it only idles very roughly (with a little pedal work) and if you try to give it gas it boogs down and will stall out. You can hear the pump prime when you turn the key.

I also don't get an engine check light with the key in ignition and don't get any error codes. The latter is strange since I'm sure there's a few in the system.

Right now its in the closest shop but I'm not sure if they put a gauge on the output pressure.


So I'm thinking Fuel pump or ECM(?)

For point of reference in case, any idea which pump and sender unit a 87 350tbi with 16 gallon tank would use. I'm seeing a couple different codes VEH VEX. Any source you guys would recommend if I do end up needing a new ECM. 1227747 ACSF.

[rfmaster]

Originally Posted by Sgt Hollywood

So my 87 Short bed (350 tbi) was running great last week. Then while cruising at 65mph on the highway it lost power, luckily I managed to hit the off ramp on the down side. Having limited tools with me and being 2hours away from home I was a bit in a jam.

Checked the filter and I do get fuel spray from both injectors, but how much is a question. But it only idles very roughly (with a little pedal work) and if you try to give it gas it boogs down and will stall out. You can hear the pump prime when you turn the key.

I also don't get an engine check light with the key in ignition and don't get any error codes. The latter is strange since I'm sure there's a few in the system.

Right now its in the closest shop but I'm not sure if they put a gauge on the output pressure.


So I'm thinking Fuel pump or ECM(?)

For point of reference in case, any idea which pump and sender unit a 87 350tbi with 16 gallon tank would use. I'm seeing a couple different codes VEH VEX. Any source you guys would recommend if I do end up needing a new ECM. 1227747 ACSF.

Sgt

Your ECM and all sensors are probably OK. What has happen is in-tank fuel line connecting Fuel Pump (FP) output port to the feed through is leaking (bursted line). You might be seeing 2-3 PSI of fuel pressure - just enough for injectors to deliver enough fuel during idle. Normal TBI fuel pressure is around 13 to 15 PSI.

1) Perform a a fuel pressure check.
2) If below 9 PSI drop tank and replace FP and in tank hose. Make sure to use SAE 30R10 rated fuel line (fuel immersion rated).

//RF

[Sgt Hollywood]

Is there any way to tell which harness I have if there is not a tag attatched. VEH VEX?
The price difference is pretty sizable between those and VEO, VEW, VEG,?

Not to mention I"ll want to order the correct part!

[Sgt Hollywood]

Not to dig up an old thread but I forgot to detail what happened, and I hate reading about an issue with no followup!

It was the fuel pump, hadn't completely died but was not putting enough pressure to get past a really starved idle. Replaced the pump and sender assembly, and some fuel tank hangers while the tank was out anyway. Unfortunately, it had died more than two hours from any suitable work space so it was done by a local garage.

Fast forward almost a month! Yeah nothing like a shop telling you how "hard it is to find parts for such an old truck" (laughable) I ended up sending him the parts....

Pick up truck, pay $$ out the rear, and get about an hour away only to have it die. Won't start, no fuel, nice! It's blowing ECM fuses like popcorn. Hmmm sounds like a short.
Yup, they pinched the injector wires when putting the cleaner on, smoking an injector.

Since I'm still 2 hrs away from home, another local guy does the repair (this guy was excellent). At least the previous garage ate this bill. Pick up truck, drive home, super happy, and then I notice that the fuel gauge isn't moving, Arrghh! Testing shows dead sending unit! Awesome, another thing that got shorted, least I have a running truck and can finally work on it myself! Not to mention a lifetime warranty on the sending unit.

[babyJay]

Thanks for the followup! Glad you got it home where you know competent hands will be doing the remainder repair work.

[turbo350]

Originally Posted by Sgt Hollywood

a shop telling you how "hard it is to find parts for such an old truck"

Yeah GM only made several million of these

Thanks for the follow-up its nice to here what the outcome was.

[rfmaster]

Well it tells you that a knowledgeable owner is a force to be reckoned with!

Happy holidays!

//RF