Andre Hedrick

Back ground:
204K miles on 4.5L stock w. PK tensioner only, and Carl's PSI rail gauge.
Small vacuum leak on brake pedal when lightly depressed, goes away when depressed hard or not at all.

Cold/Warm start and idle are fine, where warm is defined as half way between the bottom and first bar. Fuel PSI caps out at 50 or less.

As the temp rises in stop-go traffic to the first bar the idle rises from about 750 to 1300, but is still starts if I stop and shut down. Fuel PSI caps out at 50-52.

As the temp rises between the first and second bar the idle falls from the 1300 down to 400,300,200 and if I stop, she does not want to start until cooling down. The catch here is when trying to start, it sticks of injector flooding the engine and the fuel PSI rises to 60+.

Any thoughts or ideas?

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After reading other threads, they talk about the Cold Start Injector, could this cause the flooding smell?

Andre Hedrick

BUMP: The OP is hoping for comments and advice from the local brain trust.

Andre Hedrick

The OP is not feeling any love from the forum today

jpitman2

4.5L with which injection ? Sounds like you speak of L-jet, ???
My CIS 4.7S had a head hot start issue, mostly fixed by a new accumulator.
Bit more info on fuel system would help please.
jp 83 Euro S AT 54k

Mrmerlin

remove the big hose to the booster and plug it,
drive the car being careful as you wont have any power brakes.
if the issues go away then you need a new booster

Andre Hedrick

Issue appears to go away, and no booster shows about 22" of vacuum, and w/ booster it falls to 18". What is the expected range for the vacuum to fall w/ the booster, and when you step on the brakes?

Now if I hammer the brakes (sitting still) it falls from 18" to 15", then rises to 20".

What should the idle warm/hot vacuum be on an '81 4.5L?