Fuel Injector question and information

[wrightz28]

Exactly, neither the fuel pump nor opti are a fun job to do which is why it pays to cover all basis and determine where the problem lies. Your gauge should come with some basic intruction on how to isolate and determine which of the fuel system components is at fault should there be a unacceptable reading found. If not, you know you can get help here

Also, Formula has touched on a noteworthy point that sometime at idle or low throttle situation, readings will be normal, and only a road test will pin point the dropoff, however, it sounds like your problem exists at idle and should be readily apparent if ti's in the fuel system.

[rhinton]

Originally Posted by wrightz28

Exactly, neither the fuel pump nor opti are a fun job to do which is why it pays to cover all basis and determine where the problem lies. Your gauge should come with some basic intruction on how to isolate and determine which of the fuel system components is at fault should there be a unacceptable reading found. If not, you know you can get help here

Also, Formula has touched on a noteworthy point that sometime at idle or low throttle situation, readings will be normal, and only a road test will pin point the dropoff, however, it sounds like your problem exists at idle and should be readily apparent if ti's in the fuel system.

See thats the thing. It's not normally at idle. Besides the cranking up part.
When I'm driving...lets say at 1200 RPMs...you can hear that clicking noise sometimes in the engine compartment.
Then while cranking up it can take a second time just to start it up, or waaay too long of turnovers.

Oh, and the blasted Autozone didn't have a fuel pressure gauge. Just great. I'll have to go to another place tomorrow.

[rhinton]

Okay, finally got a pressure gauge that works.
And here is the deal...

Pressure when first turning key over: 47 psi

But, pressure drops. It does not stay constant. Isn't it suppose to stay at around 41 or so? It just totally drops to zero (0).

Pressure when at idle: 41 <-- I think, didn't write it down.

Anyway, I kinda figured that if the pressure drops then why not just cycle the pump once, then turn the key back to "off" then just crank it when there is pressure, and this morning it cranked right up. Guess it just means I'm not keeping constant fuel pressure.

I'm thinking about buying some new fuel injectors to start with because these "cheapy" ones I think maybe one cause to the problem as they are not solid metal like the stockers.
What was the regular stock number for the injectors? 24 lbs/sec?
And should I get the Accel Injectors from Summit or get those Ford injectors? Not sure which would be better.

[FormulaLT1]

Originally Posted by FormulaLT1

Fuel pump check valve is done. One of the first sign of a pump on the way out. On average it probably takes 3 attempts before it will start, correct?

Originally Posted by FormulaLT1

Alot of mechanics will check fuel pressure with vehicle running. See it is within specs and move on. However, this does not mean your pump is not the cause of your issue's cause the pump is suppose to meet the high demand of your vehicle and when the pressure rises and the injectors start pulsing longer and faster, if the pump can not keep up. It will lean out your mixture, raise your exhaust temps and cause missing.

Also, the check valve could not hold pressure but it will appear to be fine under light throttle conditions and idle. I just hope your mechanic gave it a good once over and if not, you should make sure to go over it to make sure it not just functioning but functioning perfectly.

Thats what your dropping to 0 means.

[goldz28]

Sounds like you fuel pump, go ahead and get the injectors because the onse you have are crap but get the pump done aswell.

[rhinton]

Originally Posted by FormulaLT1

Thats what your dropping to 0 means.

Gotcha.
Where is the check valve? Is that just part of the fuel pump? Basically just need to get a new fuel pump then?
Yeah, those injectors are garbage too.

Stock fuel injectors? What are the numbers?

[rhinton]

How about the Edlebrock pump?

http://store.summitracing.com/egnsea...=KeywordSearch

[poormillionaire2]

Stock injectors are 24lbs.

[FormulaLT1]

Originally Posted by rhinton

Gotcha.
Where is the check valve? Is that just part of the fuel pump? Basically just need to get a new fuel pump then?
Yeah, those injectors are garbage too.

Stock fuel injectors? What are the numbers?

Check valve is in the pump. You need to replace the whole pump as you already know and yes the stock injectors are 24.9LB's.

[rhinton]

Excellent.
I really appreciate the combined knowledge.
I'll let you know how this job goes. Looks like it's just a matter of getting that fuel tank off and I should be good from there.
Just have to order the parts now. "Cha-Ching"
Autozone wants around $350 for a pump...forget them.

[FormulaLT1]

Originally Posted by rhinton

Excellent.
I really appreciate the combined knowledge.
I'll let you know how this job goes. Looks like it's just a matter of getting that fuel tank off and I should be good from there.
Just have to order the parts now. "Cha-Ching"
Autozone wants around $350 for a pump...forget them.

Get a walbro pump off ebay or from from full throttle's site http://cgi.ebay.com/ebaymotors/Walbr...spagenameZWDVW . They are great for stock to 600 horsepower engines. Even though the amount of fuel pumped will increase, your regulator will keep the pressure within specs and your PCM will lessen the pulse for any change. They are what all the high performance F-body guys out there run and there is a reason for it..

[rhinton]

*whew*
Good thing I read this before I bought my Edlebrock pump.
I'll check that link out when I get home.
Work doesn't like eBay. Go figure.

[Whoaru99]

Originally Posted by wrightz28

BTW, I 've heard nice things about the injectors from those guys with blue ovals in their logo

Yup, my car runs better than it ever did with the Multecs... And a they're a BUNCH cheaper too.

The only downside is they're noiser, but at least they work.

[FormulaLT1]

I use to run 30lb SVO's and now run 42lb SVO's. If you have a modified engine, most likely you won't be hearing the solenoid clicking over the exhaust tone. Ford does make some damn good injectors though.

[Whoaru99]

Yeah, mine is basically stock. Just the simple bolt-on stuff; K&N, underdrive pulleys, SLP cat back, SLP chip, intake baffles removed, 180 thermo, etc.

The car started running odd on occasion a year ago (I only drive it in the summer months) then this spring it was running really crappy. Diagnosed two bad injectors (ohms way off spec) and one marginal. After much research decided to go with the Bosch (Ford) injectors because they were cheaper and lots of "stuff" flying around about how crappy the OEM Multecs (Rochester?) were. This is in a 91 Z.