Hard starting cold, cranks ok spark good fuel pressure good.

Don't know this car. Check fuel pressure with a fuel pressure gauge- if correct, not a problem with the pump. Also make sure the pressure will hold for some time with key off. It should hold pressure for several minutes, maybe 20 minutes, some maybe a bit less, but it must hold pressure for a time. If pressure is good, check for spark when it won't restart. If spark is lost, suspect the crank position sensor.

is this the Single head cam or twin version?
no photo of engine, so answers will be weak.

double posted. is this the single cam or twin cam engine?????? per side, the twin cam has 4 cams. 2 /bank.
i can not understand your questions, at all.
ok you overhauled the engine,
nor can i understand , still hard start.
does that mean it cranks slow and turn runs and drive perfectly ?
or cranks fast, but hard to start and runs perfectly?
or does that mean it cranks fast, starts, then misfires and runs crapppy-pappy?
hark, the devil really is in the details, no?

Generic answer.
all the wires and sensors , hoses not put back correctly.
oil full, coolant full, fresh gas in tank,
then you crank engine with no spark (I pull fuses)
and the crank it until oil pressure is good. yah, do that.

if really savvy, we check for top end oiling next. cranked only.


ok looks like oil pressure is good,(I don't want to wreck a new engine) (also check compression on a new engine, to see if we messed up., if not 150psi or more, you timed it wrong)



then we crank it, ok, it cranks and don't start
I check spark and it's timing using my timing light, it's wrong, i retime it, no and its ok. as is ..
ok sparks good, on all 6 cylinders. checked carefully and for static time.

so now start engine on test fuel,
if fails, see above for why.!
ok it runs for say 2-3 seconds and stalls. good.
We yell at the gas engine gods. O'BOY my engine seems to be OK ! progress....

next is fueling , ill stop now, as typing a book on fuel injection
is not easy here.
but fuel pressure is next. on all EFI engines. as is good fuel.
when did car last drive perfectly, 1 month ago,
10 years. what?
if long ago, the gas is bad. as are related parts all gunked up, like filters, and injectors.
and even the pump, or its sock packed in GUNK.
as you can see we have no history on the car, so.
really anything is possible. even vandalism.

btw we never just throw and engine in a car.
we check.:
1: compression, gee even sitting on a pallet.!
why install (6hr labor) a dead engine,?
2: then cranked oil pressure, spark/fuel off line.
same reasons.
3: then if all that is ok, I do check top end oiling now, if not any top end, the cams will not last very long. they will smoke and seize up in a flash.

this is how its done correctly, ask how.

hot soak ,no starts 101:
which engine?, cant guess that. say it. please."name /size"
is it flooding or starving
hard to start , so that is easy you are parked, and makes diagnosis so easy, (no need to move)
you skipped the fuel filter:?
why not use a scan tool now.?
you crank for 5 seconds, see P03xx errors. DTC'
THE ECU REPORTS ALL CMP AND CKP SENSOR ERRORS!
bingo now you have your answer , finding this, scan tool free is hard hard work. am i to tell you that hard way, sure.
1:test spark on all cylinders ,same way 100 years, google it.
2: ok sparks good, i check all spark plug tips, for wet and dry or soaked in fuel.
3: i see dry, , i use test fuel (same way for 100 years,)
run on test fuel (my Model a ford, same way works.....)
4:; ah one plug is soaking , ah leaking injector
5:ah, all plugs wet, (too high fuel pressure, ECT stuck cold
if all are wet, I stop, there are lots of tests for this.(bulleted below)

• fuel pressure (KEYON, cranking and running and W.O.T.)
• injector leak down tests. all of em;'
• injector balance test (ALL)
• Fuelpump regulator 4 tests

all this perplexing, get your ASE mechanic in the loop.

no DTCs. (even cranked for 5second, you must crank to see them. pop up, P0340 355s etc.)
all fuses good? ever do a 60k mile tune up, ever? it repeats and is critfcal.
so you crank it.
you check spark at all cylinders, 4 to 6? (no engine stated)
got spark? you check timing with a "timing light" and its
WAY OFF, opps you skipped the new cam belt, service and if you
keep cranking it , you bend the head valves. ($$$$$$$)
ok, sparks good, and timed good.
its bad fueling?
you examine spark tips
all are wet, all are dry, or 1 or 2 are wet and others dry.
(this is called evidence)
this all assumes engine compression is at spec. 150PSI or more.

we then trouble shoot , these facts.
lean? , we check for low fuel pressure. and MAP /MAF sensor and ECT
rich? same thing, but this too high fuel pressure.

how cold is it outside. -50F or +80F in florida keys)
we check that the 2 sensors match that before first start. parked overnight.
the my both be near ambient, ECT and IAT.
scan tools allow you to see all the sensors. to see if they are fibbing.
easy.
a $9 tool.

no starts.
cranks perfectly, full cranking speed, not 1 rpm but nearer 300.

ever do the 60k tuneup in the book.?
assuming the service was done and all cyl. are over 150PSI (WOT)
then we check spark first, not fuel..
The ECU brain cuts fuel (by design) any time spark is gone.
here is the proper flow:
1: throw, wild guess?, compression is good,. cam belt slip??????
is cam shaft turning,? look down oil fill hole. is it?
2: i check spark it's bad. (fix spark)
2a: i check spark its good', on all 4 cylinders not just 1.
3: spark was good. cam spins, pray compression is ok....
4: i connect scan tool, i crank for 5 seconds and see RPM rise ,good
i see ECT at say 50f (garage temp) and might see DTCs get thrown as i crank? , i see P0340 or p0355 ( one is dead CKP and other is CMP)
in my case no DTC thrown cranking , and i have spark and ECU
communicates. (key point) we alway s do that ,the tool is $9 (ask)

5: i then look at spark tips, they are:
1: soaking wet, its flooded, (spark was good but they are 10 year old.
2: dry, no fuel all spark tips day.
your engine has 4 cylinders, and all four most not flood or run dry.
i can listen to any cold start and hear gross misfire. but.....
if they are bone dry, i check voltage to the fuel pump.
it must be 12vdc cranking , 1/2 the cars you must crank. to get the pump to run ,(ECU hard logic!)
say I have 12vdc cranking
i check he fuel pressure, its not 30psi, its 5 psi (bad)
i rap the side of the fuel pressure regulator and it now is 30psi.
car starts. the reg was stuck wide open(its bad)
ok, still no start. or good pressure. Good is 30.
let say it was 60psi, i find i forgot to replace my dirty and packed up fuel filter
at the 60k mile service point. ( did i save $10 ? , no)
pretend filter is good..... pressure way low.... (examples)
so i read my FSM and it shows this shunt test, i then block (pinch)
the Fuel return line at the Fuel press. regulator.
i see 60psi, the pump is good. (do only for 5seconds ) (2 man test)
i see 10psi, the pump is bad ( of i have 12v at pump cranking,.....)
all this are pump tests there are 6 tests. not counting the injector balance test.

this is my order you can do it backwards, but will most the time have to start over, and cuss a $200 pump change , in vain.
here is the scotty way.

http://www.youtube.com/watch?v=064Ilsz8Fzg&NR=1&feature=fvwp


Example 2.
wont start, spark is good, tuneup done. sparks all 4 are wet
this is called flooding, the operators guide, says.
crank with the throttle open (WOT) car starts, it was flooded.
can happen in N.Canana (especially summer fuel in tank)
now car runs find and fresh fuel , 10 x better.
or no?
if no , post car keeps flooding, we can work that too.
is fuel pressure at 60psi, bingo, ask.






\

have you checked timing? also, check compression in all 6 cylinders.

You need 3 things.
Compression
Good hot blue spark to all plugs.
Good gasoline and proper fuel pressure. 63-64 lbs.
If you have all 3 then move on to injector pulse to all injectors.
I think each injector is on a separate driver on that one.
Check for pulse to all of them.

You may be weak on fuel pressure . even a couple of lbs low on a cold start will cause a no start.
Double check cold start cranking fuel pressure. If under 63-62 lbs you have problems.
one test is to give it a squirt of carb cleaner not starting fluid. If it starts then you have a fuel pressure problem.
Run the full fuel pressure test and post back pressures.
Here is the guide lines on testing.
Hard to start cold.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel. Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak.

The 75-85 is only a check on the capable full pressure of fuel pump.
If you can not find the rubber return line check full pressure by plugging return line or just or the true full pressure can be taken direct at the end fuel filter.
What are the pressure readings that you have when done.
What are your cold start pressure readings?
Post back what you have. Good luck

You need 3 things.
Compression
Good hot blue spark to all plugs.
Good gasoline and proper fuel pressure. 63-64 lbs.
If you have all 3 then move on to injector pulse to all injectors.
I think each injector is on a separate driver on that one.
Check for pulse to all of them.

You may be weak on fuel pressure . even a couple of lbs low on a cold start will cause a no start.
Double check cold start cranking fuel pressure. If under 63-62 lbs you have problems.
one test is to give it a squirt of carb cleaner not starting fluid. If it starts then you have a fuel pressure problem.
Run the full fuel pressure test and post back pressures.
Here is the guide lines on testing.
Hard to start cold.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak.

The 75-85 is only a check on the capable full pressure of fuel pump.
If you can not find the rubber return line check full pressure by plugging return line or just or the true full pressure can be taken direct at the end fuel filter.
What are the pressure readings that you have done.
What are your cold start pressure readings?
Post back what you have.

The other thing to that is common is the (ICM) under the distributor cap. There is a breather screen on the bottom of the distributor that get's clogged with dirt causing condensation promoting corrosion, this was gm TSB for replacing the cap and rotor to make sure it's clean.

Good luck and hope this helps. Merry Xmas.

You may be weak on fuel pressure . even a couple of lbs low on a cold start will cause a no start.
Double check cold start cranking fuel pressure. If under 63-62 lbs you have problems.
one test is to give it a squirt of carb cleaner not starting fluid. If it starts then you have a fuel pressure problem.
Run the full fuel pressure test and post back pressures.
Here is the guide lines on testing.
Hard to start cold.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak.

The 75-85 is only a check on the capable full pressure of fuel pump.
If you can not find the rubber return line check full pressure by plugging return line or just or the true full pressure can be taken direct at the end fuel filter.
What are the pressure readings that you have done.
What are your cold start pressure readings?
Post back what you have. Good Luck

You need 3 things.
Compression
Good hot blue spark to all plugs.
Good gasoline and proper fuel pressure. 63-64 lbs.
If you have all 3 then move on to injector pulse to all injectors.

You may be weak on fuel pressure . even a couple of lbs low on a cold start will cause a no start. Double check cold start cranking fuel pressure. If under 63-62 lbs you have problems. One test is to give it a squirt of carb cleaner not starting fluid. If it starts then you have a fuel pressure problem. Run the full fuel pressure test and post back pressures. Here is the guide lines on testing.
Hard to start cold.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak.

Also you mentioned that you replaced the fuel pump, it's common for the $15.00 wire harness from the fuel pump to the frame will break and there is a bad connection till the wires heat up. You can try this trick, turn your ignition on for 30 seconds "engine not running" and then turn it off for for 5 seconds and then try to start. This will energize the fuel line if the fuel line check valve is bad which is a part of the fuel pump and will heat up the wire harness which will make a better connection and see if the engine starts easier. Regardless, inspect the wire harness for corrosion and the ground is good. Good luck and keep me posted.