Just a little problem

[Divers]

Well, after playing with my newly rebuilt car for two days only one problem that I need help with.

Little background....
-rebuild engine/head
-new fuel lines and fuel pump
-distributorless ingnition
-new or rebuilt brake system (not the issue, but stated anyway)

So...car runs great for about 15-30 minutes of stop and go with quick acceleration. Than, like clockwork...will not go over about 3k RPM's. Like hitting a wall....no matter how much I push the pedal...will not go up in RPMs.....feels like if I kept the pedal pressed, car would stall. If I take it out of gear, RPM's rev up no problem. Does not matter the gear...just will not rev past about 3k. Loosened the fuel cap with no change. AFM flap maybe???

Options and opinions! Really the only thing I have found...NO LEAKS

Thanks! Robert

[ga.spyder]

Misery loves company.I hope talking to me on the phone didnt 'jinx' your car!

[Divers]

Nah! Compared to what I have done with this car...this hopefully is just a bump!

[BEEK]

can you install a fuel pressure guage where you can see it. drive the car and watch the fuel pressure when you "hit the wall" assuming the issue is under load, not free revving

[Divers]

With all new stuff in the fuel system...you really think fuel pressure? I could try to rig up something....

[BEEK]

fuel starvation or ignition breakdown, first thoughts, but you didnt mention of an ignition breakup, so i would check fuel again first

[Divers]

Did not get a chance to hook up a pressure gauge. However, did try this.

Let car idle in garage for 1/2 hour...so was good and hot. Took it for a drive and ran smoothly for about 20 mi utes then...no go above about 3k....feels like something hold the car back. Shift into nuetral and revs just fine.

Does this sound like an overheated tranny? I bought it used and only changed the fliud 90 weight mineral oil.

Robert

[So Cal Mark]

sounds like a fuel issue to me

[Divers]

Damn....hooking up the gauge is going to be a pain in the ass. I have all new lines and a new pump. Cannot be a voltage problem to the pump or it would just shut the car off. I hate shotgun troubleshooting but.........

Lets say fuel issue...what heats up ONLY when driving and then get wonkie?

[Divers]

Hooked up gauge to my cs location. Good pressure for 15 minutes at 30 psi. Problem started and saw pressure fall to 20 and then 10psi.

Fuel pressure regulator?

[Divers]

Tok a note from Craigs p,ayboom and put vice grips on the output line from the pressure regulator...thing got better, but pressure still drops....under HEAVY acceleration.


What do ya think?

[81SPIDERMATT]

similar issue for me... it was the fuel pump... did not see you mention anything about fuel tank... could be crap from the tank is schmutsing up your new pump

[ga.spyder]

Damn Robert some of these symptoms sound eerily familiar. You have a cleaned out tank,right? Did you have the TPS off the plenum? I never saw a drop in pressure with my pressure guage hooked the same way(cold start)/Pressure regulator?

[Divers]

Hoping someone can chime in. Doubt its the tank and I have new lines. Regulator is old, pump is new. How to check regulator when driving? Its ONLY something that happens after the car gets hot. If it was a partial clog should happen all the time. Dont know what the internals are of the pressure regulator, but could it be heating up with the engine heat and then failing????

Robert

[So Cal Mark]

I've never seen a regulator be affected by heat. What about the coolant temp sensor? It may be going full lean when hot