When I get stuck in traffic and the temp rises to 220,it starts missing,fuelpressure jumps around between 20# to 40#'s till she knocks off then have no fuel pressure till she cools down.This happened to me right after replacing fuelpump last yr so ended up replacing pump number of times thinkin it was the problem.Well it's done it to me twice in the last 3 weeks so I don't think it's the fuel pump.A friend thinks the hot return fuel is causing vapor lock in the tank.Anyone have this problem and if so how did you solve it?
Thanks,
BD3:hail: :bowtie:
Performance Resource

 

Yeah, it sounds like it could very well be vapor lock. Air pockets caused by that could cause the fuel pressure to fluctuate.

BTW: Ever get that chip situation sorted out?

 

What is your oil pressure at? The TPI engines gave an oil pressure switch that shuts down the fuel pump if the pressure drops too low. When the oil is hot the oil flows much easier which could cause low oil pressure if the engine is worn. If the oil pressure is fine then it could be that the oil pressure switch is worn out and needs to be replaced. The switch is located on the engine block just bove the oil filter housing, check it out, it may be your problem.

 

Im not too sure about that above statment. It has been said, but no one has really confirmed this. When my GTA had a spun bearing, at idle the pressure was at 0, but the car ran, and continued to run.

 

It has been confirmed that the oil pressure switch serves no
real purpose. That's not the problem.

Does it set any codes when it dies?

You may have a bad fuel regulator.

Because of the nature of the beast, with fuel in constant motion,
vapor lock is not possible. The fuel should never be able to get
hot enough to vaporize.

I have seen fuel regulators act normal then stick near closed
or near wide open when they get real hot. Yours might be sticking
open when it gets too hot. Then when it cools down it works
normal again.

 

oil pressure is fine just changed oil right before this happened so I was keeping an eye on the pressure.So do I need to change out the AFPR?IROC still turning better times w/ Hypertech Stage II than Performance Resource custom chip for those who wanted to know.
BD3

 

Anyone else have any ideas?
BD3

 

Have you checked fuel pressure with a guage to verify you are
loosing pressure or is it just starving for gas. You may have an
injector or two that are bad. When a bad injector gets hot it can
short out and cause the injector driver in the ECM to overheat and
shut down until it cools back off.

 

Swapmaster I have a fuel pressure gauge mounted inside my cowl hood so I can see the fuel pressure while I runnin' @ the track.Also about a month ago had fuel injectors cleaned and flo-matched at Cruizin Performance so I highly doubt the injectors are the problem.Thanks for the thoughts.
BD3

 

Just bouncing some ideas around. Next time it does it crack the
gas cap to relieve the pressure a see if it don't start right back up.

 

could a clogged cat do all of this?
BD3

 

A clogged converter will kill power big time but not cause a loss
of fuel pressure.

 

Thanks Swapmaster...we willbe doing a pressure test across the convertor to check it out.

 

How I check the converter is pull the oxygen sensor and screw a
1/2" brass nipple with a 3/8" hose barb on it and hook a Vacuum
guage to it. Use an automotive vacuum guage that has the
vacuum and pressure scales on it. Fire up the car and you should
not have more than a pound or maybe two at the most of
pressure. A clogged converter will cause a pressure reading of
like 5 to 7 or maybe 9 pounds of pressure.

 

Well converter was ok found it to be outta time.Reset timing drove fine but when I went to start this morning would'nt start.Sounds like it's outta time again.
BD3
BTW getting code #24 (vss) and the speedo isn't working.Will this stop the car from starting?Thanks

 

heres a thought..... im a dealer tech at an import dealer,and have seen some cars with similar complaints,possible junk in tank and after a while of running ,tank sock stops up.When car dies ,suction goes away and sock unstops.

Just something to think about.

 

Oh, jeez! That would suck! That'd aggravate the heck out of me!

 

I believe i have more than one problem...Seems ignition module just quit on me so I'm hoping to get the Holley from Summit in a few days.See if that was the problem.Stay tuned.
BD3