[fattboyzz65]

Just joined today.
Did a search ,but didn't find my exact issue.

89 S10 2.8 5 speed.

When I crank it ,it just spins over. A slight chug ,like it wants to fire up ,but wont.
If I prime the TBI with a lil fuel in each side, it fires right up most of the time. Take 2 or 3 tries priming sometimes though.

Any advice is appreciated 🙂👍

 

[mr.vls]

You need to measure fuel pressure on inlet to the TBI. The built in pressure regulator should be 9-11 PSI. If the pressure is below 9 psi you will have trouble and will need to rebuild or replace the pressure regulator.

 

[jimmykicker]

Either that or a weak fuel pump. I had a 2001 like that. It would fire off if you poured gas in it. Run fine for the most part. Bad pump.

 

[fattboyzz65]

I replaced the old fuel pump assembly and fuel filter. The problem remains.

I'm picking up a fuel regulator rebuild kit today from Oriellys .
Couldnt find just a regulator.

I am hoping this will end the priming to crank issue.
Then I can get on to other issues .. lol

 

[Gen210]

Sounds as if the regulator diaphram is worn.

 

[fattboyzz65]

Put the kit it to rebuild the regulator and the truck runs and sounds great.

But .. I still have to prime the TB to crank it .

At first . Just like the new fuel pump assembly, it cranked right up about 5 or 6 times. Let it set for 10 minutes and it is back to square one 😫😫

 

[oldeerslayer]

When you first turn the key to on, not start, does the pump run for a couple seconds? You should be able to hear it. Could be an electrical issue causing it to not run the prime cycle. A faulty ignition switch that only powers the pump in start could cause that. Once it starts there are other sources of power to the pump. Like the oil pressure switch.

 

[fattboyzz65]

When you first turn the key to on, not start, does the pump run for a couple seconds? You should be able to hear it. Could be an electrical issue causing it to not run the prime cycle. A faulty ignition switch that only powers the pump in start could cause that. Once it starts there are other sources of power to the pump. Like the oil pressure switch.

Yes . When I turn the key on, I hear the pump run. Then I hear the relay click.

 

[oldeerslayer]

Since it is priming properly and the pump, filter, and regulator are all new don't know what to suggest other than doing a pressure test to be sure you're getting 12-15 at the TB. I suppose the injectors themselves could be failing? 😕

 

[Gen210]

Fuel pressure test is needed, I suspect the pump does not have enough pressure for initial pressurization but will flow once started. All points to a weak pump

 

[fattboyzz65]

Fuel pressure test is needed, I suspect the pump does not have enough pressure for initial pressurization but will flow once started. All points to a weak pump

Pump assembly is new

 

[Rhotpursuit]

Pump assembly is new

If everyone here had a nickel for every new pump that was bad out of the box…..Jeff Bezos would still be selling books out of his garage. Check the pressure.

 

[fattboyzz65]

If everyone here had a buckle for every new pump that was bad out of the box…..Jeff Bezos would still be selling books out of his garage. Check the pressure.

You guys here are willing to help me chase this gremlin and I appreciate it

 

[jimmykicker]

My instructor in college said, "You can have 100 distributor caps...doesn't mean any of them are any good...." I've put new parts on that were defective. On these old rigs I'd advise getting an inexpensive gauge and leaving it inline.

 

[fattboyzz65]

I was reading a blog on the subject and it said to make sure my system was primed well from new pump to Tbi. I replace the hose from the hard line in the frame and relocated the new fuel filter away from any heat sources. Also bought new relays and an O2 sensor.

The truck is running gr8 now and cranks everytime I hit the key.
The exhaust no longer smells rich.

Thanks everyone !

 

[jimmykicker]

I was reading a blog on the subject and it said to make sure my system was primed well from new pump to Tbi. I replace the hose from the hard line in the frame and relocated the new fuel filter away from any heat sources. Also bought new relays and an O2 sensor.

The truck is running gr8 now and cranks everytime I hit the key.
The exhaust no longer smells rich.

Thanks everyone !

Excellent! Thanks for the update on it. On something like that, it's ok to fire the parts cannon on it. I did the same with mine with an easy to reach fuel filter. Wonder if it had to do with the hose itself? Perhaps collapsing on itself and forcing the fuel back down the line, or some kind of line vacuum. Who knows. I've seen all kinds of weird stuff myself over the years.

 

[alexgranich]

I was reading a blog on the subject and it said to make sure my system was primed well from new pump to Tbi. I replace the hose from the hard line in the frame and relocated the new fuel filter away from any heat sources. Also bought new relays and an O2 sensor.

The truck is running gr8 now and cranks everytime I hit the key.
The exhaust no longer smells rich.

Thanks everyone !

Can you put some pics of how you route the lines....

 

[fattboyzz65]

I just made a bracket and mounted the fuel filter over on the fenderwell away from any heat sources..

 

[alexgranich]

thanks for the idea, much easier to change the filter and safe, and a lot of room to put any pressure gauge if you want to...