I followed Vaders Tech article on making an adjustable fuel pressure regulator. My car is a 1989 IROC 350. We just had it recently rebuilt so now it is a 355( bored 30 over). Trying to get it to run has been a complete headache. We have reset the timing many times. Checking the TPS resulted in a .4 and less with the throttle valves closed and .9 at WOT. We went and bought a new one after we decided that the old one couldn't be adjusted properly. After hooking up the new one it sat perfectly at .54 but at WOT it is still around 1.0, don't know why.

So, getting to that fuel pressure regulator, we decided to see how much pressure there was when the engine was turning over, since it doesn't want to run. We first pulled the vacuum line off the fpr and plugged it leaving the afpr nipple open. Our result on the gauge was 60psi. That didn't seem right so we plugged the nipple on the fpr and left the vaccuum line open. Same result. We then put the vacuum line on to see if that changed anything.. nope still 60psi. I know that is not the desired pressure for a mostly stock engine. The bolt on the fpr is not putting any pressure on the spring, So it should be the stock pressure shouldn't it? Is it possible for me to get a proper reading just cranking over the engine? or does it need to be running? Could it be a vacuum problem?

The car ran fine before we rebuilt it, although it did smoke bad. The only mod is the fpr being made a afpr. But it should be like 42psi shouldn't it? not 60. Any of ya have any possible idea's as to what my problem is? Thanks a bunch..


Steve

 

Spearson,

Did you use the steel ball or the flat disk to take the pressure of the adjustment screw?

If you used the steel ball, you need to read the warning in the article about the size of the ball and the contact area on the spring end, to make sure the ball doesn't contact the plunger at the center of the regulator. I had to use a 0.315" ball in mine to barely contact the spring plate and avoid the plunger.

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Later,
Vader
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"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

I used the 3/16 steel ball as said in your article. There is no warning in the article I have, have you changed or updated it recently?

 

Vader, I'd like to see that article, but don't see it in the tech section here, where can I see it please?

 

If you are using the article found at MikeInAZ's site,it is incorrect. The article to which I post links is the correct one. I emailed Mike a long time ago asking to update the article, and haven't checked it recently to see if it was updated.

The correct article is here: AFPR.pdf

The warning about checking the ball size and contact area is at the last page under assembly/adjustment instructions.

------------------
Later,
Vader
------------------
"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

Ok, I have fixed the fuel pressure problem, back down to the mid 40's. But here is what is happening now: When we turn the engine over it is chugging, but won't start, when we stop turning it over it chugs by it self for a sec then quits. When we turn the distributer all it does is either chug faster or not at all. Could this be like a pickup coil problem or just timing?

 

Spearson,

How do the spark plugs appear? If they are fuel-fouled, you might be getting very poor ignition. If not, you still may have a weak ignition or severe timing problem. Verify the wire positions and firing order, and make sure the base timing is correct. An approximate guide should be to have the distributor rotor contact pointing toward the #1 cylinder when the #1 is at TDC on the compression stroke.

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Later,
Vader
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"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

Hey Steve, mines on the road . I also managed to get a B in Calc..... WTF????

Anywaysss.... It sounds to me like you are 180* off on your base timing. This is a very easy thing to mess up so I would double check that. How is the battery? It sounds like you have been cranking away on the battery a lot and maybe it has lost some power and no longer is feeding the ECM enough juice to fire the injectors properly. This could also explain the low readings on your TPS.

There's a couple ideas for ya to try.

I also don't remember you saying anything about rebuilding the engine before??? Or was it already rebuilt before the head/bolt fiasco?

Anywho..... Let me know if ya need a hand working on it.

Laterzzzzzzzzzzzzzzzzzzz

Matt
email: pontiacgta@mediaone.net

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1987 GTA L98 MD8 GH3
355 '97 Vortec 4-bolt block, TRW(suck) forged pistons 10:1 CR, TFS 23*, LT4 Hot Cam, Ported plenum and intake, SLP Siam Runners, Edelbrock TES, gutted Cat, Flowmaster, Home-made cold air system w/ K+N cone, AFPR, TB bypass, AirFoil, !AIR, !A/C, !EVAP, 2300 stall.

"Stop Lights timed for 35Mph are also timed for 140Mph"

[This message has been edited by Matt87GTA (edited June 12, 2001).]

 

Got it, thanks Vader!

 

Vader, we have set and reset the base timing numerous times now, verified all the wires are where they should be, even readjusted all the valves just in case. The plugs do seem slightly fuel fouled. We even bought a new coil because the old one failed all the tests, and still nothin.. This is getting so frustrating.

Matt, heh I got a C in calc, wonder how I did on that final hmm ? When we took the heads off it was very obvious that the rings were shot, so we had it bored 30 over, now it is a nice fresh engine that doesn't run.. go figure. No the timing is not 180 out, that was an error we fixed at the very beginning. Brand new optima battery, been running it dead every day just about, charging it over night, great battery by the way. Brand new TPS, readings are just fine now. On the road already? how is it?

How can I go about testing my ECM?, we have gone through everything else over and over again, might as well test this thing as well.

Once again, Thanks
Steve

 

Well we figured it out, the EST was disconnected, as soon as we reconnected that, it fired right up, just need to get the rockers properly adjusted now and reset the IAC..

 

Sounds like we'll have to do some cruisin soon than. Are you still planning on selling it or are you gonna keep it since you put the time/money into rebuilding the engine? Tell me you put a better cam in it and did some head work......

Anywho... gotta run. BTW, I got that internship with Qwest for the summer so I am making some pretty decent $$$. I got some more plans in the works for the GTA hehehehe.......

Laterzzzzzzzzzzzzzzzzzzzz

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1987 GTA L98 MD8 GH3
355 '97 Vortec 4-bolt block, TRW(suck) forged pistons 10:1 CR, TFS 23*, LT4 Hot Cam, Ported plenum and intake, SLP Siam Runners, Edelbrock TES, gutted Cat, Flowmaster, Home-made cold air system w/ K+N cone, AFPR, TB bypass, AirFoil, !AIR, !A/C, !EVAP, 2300 stall.

"Stop Lights timed for 35Mph are also timed for 140Mph"

 

Nope stock cam, heads were decked slightly, not that that will do much if any. Yes, I am going to sell the car probably next summer. It just isn't worth putting performance parts on this car. The underside of the car is a headache in itself. And I want nothing to do with it. So next summer it is going out the door after we touch up the body a little bit.