Cuts out when accelerating

[01Indian]

I have an 88 Sierra, cuts out when accelerating, changed tps, map coolant temp sensor, cap router wires plugs, fuel filter and still has same problem would appreciate any help 171k

 

[01Indian]

Meant rotor

 

[Alteca]

Probably fuel pressure, check electrical connections/grounds especially to the fuel pump

 

[Schurkey]

Stop changing parts at random.

As said, verify fuel pressure.

Connect a scan tool, look at the data stream, especially fuel trims, MAP sensor, and TPS voltage.

 

[tsr2185]

I have an 88 Sierra, cuts out when accelerating, changed tps, map coolant temp sensor, cap router wires plugs, fuel filter and still has same problem would appreciate any help 171k

what shurky said. Check CEL codes too. bad O2 sensor did that to my father in laws S-10 TBI, easy and cheap.

 

[01Indian]

Ok, I bought an innova 3170rs scanner. The old GM obd1 showed no codes. When I plugged this in it showed 8 codes, 31,32,33,35,43,52,54 and 55. This was a neglected truck showing 171,000. The plugs looked good, compression was solid. Just need a direction, picking up an o2 sensor tomorrow. Appreciate any help. Thanks

 

[PlayingWithTBI]

When I plugged this in it showed 8 codes, 31,32,33,35,43,52,54 and 55.

With all of those codes I'd guess you either have a grounding issue, blown fuse(s), or a bad ECM (code 55). Is your BCC chip (in the plastic holder) plugged in? You're probably running on limp mode.

www.repairpal.com/gm-obd-I-code-chart

GM OBD I Trouble Code Chart

Code Description Code 12 No distributor reference pulse (diagnostic test active) Code 13 Oxygen sensor circuit open or no

repairpal.com

 

[Schurkey]

VERIFY FUEL PRESSURE.

You have those codes written-down for future reference. Clear the codes, drive the thing. See which codes come back. Since you don't know the history of the truck, you don't know how many--if any--of those codes are "false" or have already been fixed with the heap of parts you've changed. They're not reliable. Clear 'em, start over. The codes that come back are likely genuine.

The 50-series codes are scary. Hope those don't reappear.

A fresh O2 sensor is generally a good idea. O2 sensors, and MAF sensors (NOT MAP) are about the only sensors that seem to have a limited service life. All the other sensors "can" fail, but their lifespan is totally unpredictable. O2 sensors get old 'n' lazy 'n' contaminated with use. But you could use your new scan tool to see how fast it's switching--either by looking at the graph (if available) or by seeing if the tool displays O2 cross-counts. Faster switching/more cross-counts is better. USUALLY, if the O2 sensor has adequate cross-counts or fast switching, it's OK--but not always.

Aside from the "codes", look at the data stream. That's where the REAL information is. Verify EVERY sensor's input to the computer using the scan tool, and take time to inspect the computer outputs--EGR, spark advance, AIR, (if used) make sure the injectors are firing with a nice pattern, and the fuel trims are reasonable, etc.

 

[01Indian]

Stop changing parts at random.

As said, verify fuel pressure.

Connect a scan tool, look at the data stream, especially fuel trims, MAP sensor, and TPS voltage.

It’s obd1 how do I get live data?

 

[01Indian]

Fuel pressure is at 6psi