86 hard start
Thread Starter
Instructor
Joined: Jul 2006
Posts: 138
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From: Eagle River Alaska
86 hard start
...just replaced a leaking injector on my 86 since I was experiencing hard starts due to flooding. I'd have to hold down the throttle and crank for about 3-4 second to get it going. checked all other injectors at the spark plugs for leakage and all appear good. Checked fuel pressure for holding and holds good and running pressure is good as well. Starting is slightly better but still about the same hard starting as before I replaced the leaking injector.
fuel filter is new too.
My valve seals need to be replaced as there is a small puff of wht smoke on startup if the car sits for 8 hours or so. not too bad though, but I don't think that should give it a hard start condition.
What else should I look for???
fuel filter is new too.
My valve seals need to be replaced as there is a small puff of wht smoke on startup if the car sits for 8 hours or so. not too bad though, but I don't think that should give it a hard start condition.
What else should I look for???
Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
You can use your fuel pressure gauge to check to see if the ECM and fuel pump relay are priming the fuel system. That would delay starts until the oil pressure switch was activated.
White smoke (steam) is usually associated with coolant going through the engine, rather than oil.
RACE ON!!!
White smoke (steam) is usually associated with coolant going through the engine, rather than oil.
RACE ON!!!
Thread Starter
Instructor
Joined: Jul 2006
Posts: 138
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From: Eagle River Alaska
not sure i understand what your saying. I assumed the fuel pump relay is working since the system pressurizes when I turn the ignition on and not actually crank the engine over.
Are you talking about a different kind of test?
also the car fires right up on the first start of the day after it sits all night long, but after that it cranks for about 5 seconds unless i hold the pedal down and then it cranks less, maybe like 2-3 seconds till it weakly fires up then goes to a normal idle and everythings fine.
as for the smoke i'm not too concerned about that right now, it smells a little of oil and not sweet so that is why I am pretty sire it's the stem seals as it did the same thing on my 87 I had years ago. I just want to get this hard starting thing dealt with it's irritating me....
Are you talking about a different kind of test?
also the car fires right up on the first start of the day after it sits all night long, but after that it cranks for about 5 seconds unless i hold the pedal down and then it cranks less, maybe like 2-3 seconds till it weakly fires up then goes to a normal idle and everythings fine.
as for the smoke i'm not too concerned about that right now, it smells a little of oil and not sweet so that is why I am pretty sire it's the stem seals as it did the same thing on my 87 I had years ago. I just want to get this hard starting thing dealt with it's irritating me....
Race Director
Joined: Jun 2005
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From: Lenoir City TN
St. Jude Donor '08-'09-'10-'11
Did you replace them all or just one? Sounds like you still have leaking down, this was exactly the symptoms on my 86 until I had all injectors serviced.
Edit: Never mind I can not read tonight, I would get them all serviced or replaced.
Edit: Never mind I can not read tonight, I would get them all serviced or replaced.
Burning Brakes
Joined: Aug 2006
Posts: 780
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From: New Port Richey Florida
With rspreng I would get all the injectors serviced, don't think white smoke is from valve seals that is usually blue/black smoke, I would say the engine is still flooding causing hard start and white smoke. IMHO 
Thread Starter
Instructor
Joined: Jul 2006
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From: Eagle River Alaska
Makes sense... is there another way to check the injectors for leaking besides checking for fuel pressure holding(which it is) and pulling the plugs? All the plugs are dry as well...
I only get the puff of whitish smoke when I let the car sit for about 6-8 hours after it was running. all other times there is no smoke puff.
I only get the puff of whitish smoke when I let the car sit for about 6-8 hours after it was running. all other times there is no smoke puff.
Race Director
Joined: Jun 2005
Posts: 17,640
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From: Lenoir City TN
St. Jude Donor '08-'09-'10-'11
Keep an eye on the coolant, you could also have a coolant analysis done to see if exhaust gases are in coolant or whatever it is called, as well as applying pressure to the coolant system and see if the pressure holds. Do on cold engine.
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Le Mans Master
Joined: Aug 2003
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From: Magnolia Mississippi
St. Jude '03-'04-'05-'06-'07
You have 2 different issues:
1. Hard start: Fuel pressure test and injector leakdown to find the problem injector or injectors (prob best is to pull them and have Rich at Cruzin service all)
2. White Smoke: Nothing to do with hard start... as said by others, thats a coolant issue, if your only getting a puff, which alot of c4's do, i'd address the hard start injector issue.
1. Hard start: Fuel pressure test and injector leakdown to find the problem injector or injectors (prob best is to pull them and have Rich at Cruzin service all)
2. White Smoke: Nothing to do with hard start... as said by others, thats a coolant issue, if your only getting a puff, which alot of c4's do, i'd address the hard start injector issue.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
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From: Louisiana
They I would think it is an injector(s) issue. You seem to have adequate fuel pressure and have noted that the fuel pressure builds with the key turned to the on position.
My suggestion at this point is to ohm the injectors first thing in the morning and then drive the car to operating temps and shut the engine off and ohm test the injectors again. They all should ohm over 10 ohms and be very close to one another. Usually with bad coils, the resistance readings will change when the coils have warmed up.
My suggestion at this point is to ohm the injectors first thing in the morning and then drive the car to operating temps and shut the engine off and ohm test the injectors again. They all should ohm over 10 ohms and be very close to one another. Usually with bad coils, the resistance readings will change when the coils have warmed up.
Race Director
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Cruise-In II Veteran
When it has a chance to sit all night,the fuel leak stops,it evaporates inside the combustion chamber and the plugs become dry,making it easy to start in after all night or several hours.
That being said,You replaced a bad injector and theres a very high chance theres a few that are leaking and are on the way out.
With an older 8 injector systems,its always a good idea to do them all at once if they havent been done before.
Thread Starter
Instructor
Joined: Jul 2006
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From: Eagle River Alaska
looks like i'll be buying 7 more injectors soon.... damn... thought i'd fix it with replacing the 1 bad one i thought i only had...
....off goes the plenum again... might *** well polish it this time while it's off again!
Now I can't sleep! i'm starting to worry about my puff of smoke on startup not being the seals and the start of a major problem!
....off goes the plenum again... might *** well polish it this time while it's off again!
Now I can't sleep! i'm starting to worry about my puff of smoke on startup not being the seals and the start of a major problem!
Le Mans Master
Joined: Feb 2006
Posts: 8,753
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From: Louisiana
Go ahead and ohm the injectors. Try to pinch off the feed fuel line at the tank quickly AFTER priming the fuel system. If the pressure leaks down, that tells you there is a lead outside the tank (line, connection, FPR, injectors). The puff of smoke is likely just valve seals. Check the oil for signs of water/coolant.
Thread Starter
Instructor
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From: Eagle River Alaska
RRT, no water/coolant ever in oil. Coolant level is always the same as well. At around 3000 miles the oil is around 1/2 qt low at the most. Which is why I've always thought valve seals.
As for my injectors I will try and ohm tomorrow after work. Just to make sure to properly ohm test them I connect both poss and neg terminals of my voltometer to the injector leads? and they should read 11 or higher with the ignition off right?
...couldn't find anything in the FSM about ohm test just injector balance test and I don't have the tool to turn the injectors on 1 by 1 that it talks about having in there.
As for my injectors I will try and ohm tomorrow after work. Just to make sure to properly ohm test them I connect both poss and neg terminals of my voltometer to the injector leads? and they should read 11 or higher with the ignition off right?
...couldn't find anything in the FSM about ohm test just injector balance test and I don't have the tool to turn the injectors on 1 by 1 that it talks about having in there.
Team Owner
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From: Summerland B.C. Canada
Le Mans Master
Joined: Oct 2003
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From: seattle WA
about the seals. Make sure you set your meter on ohms, and yes, you got the rest right as far as testing goes. I also agree with it really sounds like injector(s) leaking on the hard start. That's why you ohm both cold and warmed up, resistance changes with heat. Hard lesson learned, not just for you, but if you find one or two injectors bad the rest are usually just behind, best to replace all 8 at the same time. As far as pinching off the fuel line, you can do that if you want, but if it's starting after sitting a long period of time I really doubt you have fuel pump or regulator problems.
Thread Starter
Instructor
Joined: Jul 2006
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From: Eagle River Alaska
ohm tested my injectors and here's what I got:
engine cold= all injectors at 16.5 and one at 16.7
engine hot (199F.)= 6 inj. at 17.5 and 2 injectors at 17.3-17.4
So all are above 11 do these numbers look good? And also I'm not sure what this tests for, does this just test to tell if my injectors are receiving signals from the ECM? Or does this tell if I have another leaky injector?
engine cold= all injectors at 16.5 and one at 16.7
engine hot (199F.)= 6 inj. at 17.5 and 2 injectors at 17.3-17.4
So all are above 11 do these numbers look good? And also I'm not sure what this tests for, does this just test to tell if my injectors are receiving signals from the ECM? Or does this tell if I have another leaky injector?
Le Mans Master
Joined: Feb 2006
Posts: 8,753
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From: Louisiana
The test looks good and verifys that the injector coils are up to par. That test doesn't tell you about leaky injectors or that the injectors are receiving signal (need a noid light for that).
Have you looked at the spark plugs? Where they all the same color? Any wetness or white plugs?
Have you looked at the spark plugs? Where they all the same color? Any wetness or white plugs?