TBI problem, Truck won't stay running

[JCribb]

So it sounds like by reading this thread, that tuning these little machines isn’t really all that complicated as it first seems, is that a fairly accurate statement?

I’m only asking because I have not read the data, nor have I ever logged anything of the sort. I only have the new chip set up by fastchip when I paid him three years ago. I haven’t done anything other than a fuel pump since that time, but I’m always wanting to learn more to see if something else can be done to fine tune it more.

I had considered buying the self learning efi, but at easily a grand to get started, that’s not easy money to part ways with.

 

[Darrell]

I had considered buying the self learning efi, but at easily a grand to get started, that’s not easy money to part ways with.

I too was thinking the same..self learning, no brainer..I think ! But nearly a grand is what lead me to asking for help and trying to maybe figure this TBI out.

 

[Darrell]

Your fuel pressure should be 12.5-13, not 11. The difference won't be earth shattering, but it is at least 1 thing that isn't right. Once you have an ALDL cable, try bumping base timing to 4 degrees and monitor for knock if the TBI motors have knock sensors? I think they do. You did add 16 degrees to the intake lobe and likely as much to the exhaust. .385" on the intake sounds stock, you sure that's right? While it isn't much cam, the stocker was pathetic and this could cause an off idle stumble if that's the only real issue you're experiencing.

This is my fuel pressure reading, If I should be getting a little more and this is one problem, is this meaning a new fuel pump in the tank ?

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[Darrell]

Your fuel pressure should be 12.5-13, not 11. The difference won't be earth shattering, but it is at least 1 thing that isn't right. Once you have an ALDL cable, try bumping base timing to 4 degrees and monitor for knock if the TBI motors have knock sensors? I think they do. You did add 16 degrees to the intake lobe and likely as much to the exhaust. .385" on the intake sounds stock, you sure that's right? While it isn't much cam, the stocker was pathetic and this could cause an off idle stumble if that's the only real issue you're experiencing.

My error, my correct cam is

Edelbrock cam 3702:
194/214 intake/exhaust duration @ .050"
.398/.442 intake/exhaust lift
112 degree of lobe separation

I believe the stock cam specs were
165/175 intake/exhaust duration @ .050"
.382/.402 intake/exhaust lift

I ordered the ALDL cable and software, hopefully have by mid next week.

 

[Supercharged111]

No need for a pump, just need an adjustable FPR.

http://rvmorsemachine.com/product.htm

 

[JCribb]

No need for a pump, just need an adjustable FPR.

http://rvmorsemachine.com/product.htm

I probably have way more fuel than I will ever need, pump, modded unit from Morse, spacer. I don’t have a gauge or adjustable regulator, but I do have the 18psi spring.

I commented here to learn more about the system.

 

[Supercharged111]

My regulator only went as low as 15. My TBI truck had long tube headers (now on current 1500), injector pod spacer, and chopped the extra metal off the top of the TB, timing at 4 degrees, and ran premium fuel as I did not have the ALDL cable. It acted a little weird, so I suspect 15 was a smidge too high.

 

[PlayingWithTBI]

I probably have way more fuel than I will ever need, pump, modded unit from Morse, spacer. I don’t have a gauge or adjustable regulator, but I do have the 18psi spring.

I got the 62-FP, 62-FR, and the 62-PG

http://www.rvmorsemachine.com/orders.htm#FP62

 

[68vett]

Hey all, I've continue to have some sort of TBI problem since it's rebuild.

I have a '95 TBI with a couple issues.

1) The throttle blades are sticking now (This is new) but only after it's been running then shut off and it sits for a few minutes. If I try to restart the throttle pedal won't move until it's press hard and then it frees itself and operates normal. This is only on the initial start up and only after it's sat for a while.

2) I've replaced several sensors, TPS, IAC, Throttle body temp to be exact. I was getting the code flashes for these so I've replaced them. Fixed, I no longer get any codes flashing except the normal "1-2" flashes at the beginning.

BUT...the problem is that once it's started (after the sticking blades free up) it won't stay running once I crack the throttle. Whether it's from inside on the pedal or under the hood at the throttle linkage.

I'm showing approx 10-11 psi on my fuel gauge at the rear of the TBI, so that seems good..I think

Not sure if I'm getting to much fuel and it's choking itself out or what..but once it's starts up I'm getting black smoke and black soot specs all over the driveway....

any suggestions.....I'm about the scrap this TBI and look for an alternative replacement !

Thanks in advance

I've read you post and feel your pain... I have a 94 Gmc had the same issues. Did everything to fix the issue of die at idle while in gear. I mean everything! IAC,, TPS,, Fuel pressure,, Complete Tune Up,,, plugs, wires, cap, rotor and ignition module,, Checked all grounds,, Temp sensor., Timing,, New Computer.. EVERYTHING!! The item that fixed it was something no one ever talked about as a problem,, the hall effect part in the distributor was weak.. Installed a rebuilt distributor... Problem solved... Been running great for 5 years..

 

[Darrell]

No need for a pump, just need an adjustable FPR.

http://rvmorsemachine.com/product.htm

Btw..Been so damn busy and haven't had a chance to jump back on the truck, but today I decided to start and check out the fuel gauge at the back of the TBI and I notice even a lower pressure. It was at 5 psi and holding.

Going to order an adjustable FPR

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