84CUCV
3/4 ton status
I think this is my next step. anyway i could run a gauge into the cab? if its worth it. thanks
CK5
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How to test fuel pressure
- Thread starter 84CUCV
- Start date
Never had to test, but my understanding is that you can test for "leakdown" (turn key to run, watch to see if pressure peaks around 13, and if it keeps pressure) and then also test for pressure at idle.
Without an electric setup, I'd suspect it would be considered dangerous to run a long rubber hose full of gas to the cab. Can't see a reason it wouldn't work though.
In any case, I don't really see the validity of checking the pump while driving, the fuel pressure should never change, (within reason) since it's got a pressure regulator and a return, as fuel demand increases, the amount returned to the tank simply decreases. (voltage isn't variable to the pump, so it's on or off)
Without an electric setup, I'd suspect it would be considered dangerous to run a long rubber hose full of gas to the cab. Can't see a reason it wouldn't work though.
In any case, I don't really see the validity of checking the pump while driving, the fuel pressure should never change, (within reason) since it's got a pressure regulator and a return, as fuel demand increases, the amount returned to the tank simply decreases. (voltage isn't variable to the pump, so it's on or off)
84CUCV
3/4 ton status
i was thinking it was not getting the right pressure. it cant even idle. thanks
Seeing as I've not had to deal with this, I don't really know where you start looking if it won't even idle, if you suspect fuel. It would seem, assuming fuel is the problem, that if it can't idle, then pressure would be low if it were the pump or leaky injectors. If that was the case, even a test of pressure with the truck off, pump primed, should show the problem in my mind.
Hopefully you can get some info from others here that may already be running a guage, or have diagnosed this.
You can at least start it though I assume? Can you keep it alive with throttle?
Hopefully you can get some info from others here that may already be running a guage, or have diagnosed this.
You can at least start it though I assume? Can you keep it alive with throttle?
rolereversal
1/2 ton status
When is the last time you fuel filter was changed?
84CUCV
3/4 ton status
changed about two weeks ago.. think i might have got it. cant believe i over looked this. the injectors barely spray anymore. so that is step one for now.. injectors are pricey. 240 for them. thanks for the help
Where did you look for injectors?
I bought my injectors (granted, there are 8, so more sales volume potential) from Summit, and they were quite a bit cheaper than elsewhere.
I agree, test things out first. If it weren't so pricey to have them cleaned/tested I'd suggest that route, but I believe they are upwards of $75 for that procedure. Besides, as old as they are, probably best to replace if in doubt.
I bought my injectors (granted, there are 8, so more sales volume potential) from Summit, and they were quite a bit cheaper than elsewhere.
I agree, test things out first. If it weren't so pricey to have them cleaned/tested I'd suggest that route, but I believe they are upwards of $75 for that procedure. Besides, as old as they are, probably best to replace if in doubt.
Is this the Suburban you're fighting? 
Low fuel pressure will cause the injectors to barely dribble fuel. Check the fuel pressure before going any further!!!
Fuel pumps die a lot more often than injectors do.
The easiest way to check fuel pressure on a TBI truck is to buy the adapter that goes in place of the fuel filter, the adapter has a schrader valve that a regular fuel pressure test gauge connects to.
Low fuel pressure will cause the injectors to barely dribble fuel. Check the fuel pressure before going any further!!!
Fuel pumps die a lot more often than injectors do.The easiest way to check fuel pressure on a TBI truck is to buy the adapter that goes in place of the fuel filter, the adapter has a schrader valve that a regular fuel pressure test gauge connects to.
84CUCV
3/4 ton status
ok i was looking at this.
http://marine-performance-parts.com/cfmtechfuelpsiguageadaptorforgmtbi2843505774.aspx
thats a lot of coin tho. thanks
http://marine-performance-parts.com/cfmtechfuelpsiguageadaptorforgmtbi2843505774.aspx
thats a lot of coin tho. thanks
That will work good, made more for a permanent install though.
This is what I had in mind, little less money and can be left in the tool box for the next problem child.
http://cgi.ebay.com/ebaymotors/GM-T...022QQitemZ350001635770QQrdZ1QQsspagenameZWD1V
This is what I had in mind, little less money and can be left in the tool box for the next problem child.
http://cgi.ebay.com/ebaymotors/GM-T...022QQitemZ350001635770QQrdZ1QQsspagenameZWD1V
84CUCV
3/4 ton status
ok thanks will be getting one.
84CUCV
3/4 ton status
do you know of one that comes with a pressure gauge too? cant find this tool any were around where i live.
E-bay is your best bet. NAPA shows one for over a $100.00. For that much money you'd be better off shotgunning a fuel pump.
84CUCV
3/4 ton status
okk i will get. then i will find a gauge
