'87 350 TBI, advice needed for basic operation...

Hey Guys, I've done quite a bit of research here, but this is a unique situation. Back in 2014 I picked up an '88 r30 w/ 350 tbi to use as the base for a mutant vehicle I was creating. I have since radically modified the rig, including relocating the driver controls.

The vehicle never drives faster then 15-20 mph, averaging 5mph, and most of the time during operation she sits at idle turning two high output alternators provided power back to 4 12v "house" batteries

The one issue im having is the motor runs very rich at idle and upon acceleration.

I purchased a new wiring harness, new injectors, new o2 sensor, temp sending unit and Map sensor. When relocating the driver controls, the only wiring I brought up to the new location is ignition. I installed new afermarket fuel, temp and oil pressure gauges. Needless to say, I dont have the idiot lights ie: service engine lights etc. Of course, the new wiring harness does have the code reader, I'll attempt to get a hold of a reader and see if its pulling any codes.

I'd like to keep the tbi running with the bare min sensors etc. Which wires/sensors dont I need? What could be causing this extreme rich conditions? Outside of the motor running rich, she runs great, well except that it take 3-4 cranks of the motor to fire up.

I dont have to worry about emissions either as this will never be registered to be a street legal rig. Primarily for festivals, parades and special events.

Thanks in advance.

I had a bad coolant temp sensor which made the computer think that the engine was always running "cold" and therefore "richened" the mixture. Lots of sooty exhaust, poor idle etc.

if you dont have the efi tuned to remove those sensors you will cause a code and this will set the ecm in limp home mode causing it to be rich and lazy on timing. Get live data feed to see what is going on.

I had an '88 k1500 with that engine for a few years. Always smelled rich at idle, but also always turned in a respectable mpg figure (15-17 mpg if you could plan trips with lots of steady driving at 60mph) for a 30 uear old 4x4. I think it has to do with how the injectors deliver the fuel which is akin to this. For what it's worth, the entire time I had it, it was a dependable vehicle that never failed to start or run.

5akman said:

I had a bad coolant temp sensor which made the computer think that the engine was always running "cold" and therefore "richened" the mixture. Lots of sooty exhaust, poor idle etc.

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I've changed out the sensor, twice with thoughts maybe the newer one may be faulty. This didnt fix the issue.

4WDKC said:

if you dont have the efi tuned to remove those sensors you will cause a code and this will set the ecm in limp home mode causing it to be rich and lazy on timing. Get live data feed to see what is going on.

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Bingo!! Please, how do I go about doing this?

mrgto said:

Bingo!! Please, how do I go about doing this?

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That depends, how far down the rabbit hole are you prepared to go?


Go make yourself a large plate of food with snacks. get a large bottle of your favorite soda and start reading here. http://www.gearhead-efi.com/Fuel-In...ou-start-when-tuning-a-chip-Update-10-24-2011

If you google search you will see alot of people say to use TBIchips but from what I have read and learned I would tell you not to. DaveW on the site above does tuning and maybe able to help you but unless you live close to him you will have to do the leg work that he cant.

4WDKC said:

That depends, how far down the rabbit hole are you prepared to go?


Go make yourself a large plate of food with snacks. get a large bottle of your favorite soda and start reading here. http://www.gearhead-efi.com/Fuel-In...ou-start-when-tuning-a-chip-Update-10-24-2011

If you google search you will see alot of people say to use TBIchips but from what I have read and learned I would tell you not to. DaveW on the site above does tuning and maybe able to help you but unless you live close to him you will have to do the leg work that he cant.

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Haha, thanks. Not too far down, considering I just need the engine to perform well at idle and up to 15mph ;-)

I don't care about fuel economy or emission controls, however I would like a fast idle situation 1,000-1,100 rpms to keep those alternators happy.

However, I would consider a custom chip for this my application.

.

mrgto said:

Haha, thanks. Not too far down, considering I just need the engine to perform well at idle and up to 15mph ;-)

I don't care about fuel economy or emission controls, however I would like a fast idle situation 1,000-1,100 rpms to keep those alternators happy.

However, I would consider a custom chip for this my application.

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contact DaveW on that forum he may be able to swap you ecms for one that is already modified for a new and less expensive chip that he can tune for you.

Check your ecm ground.