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I have 1989 Ford Thunderbird Supercoupe. It cranks but no start. I changed fuelpump, fpr, crankshaft position sensor. I checked that fuel injectors spray and it has spark. If I spray fuel into the throttlebody, the car will start and it runs by itself. It runs rich but still it runs.
So. I also noticed that it is misfiring and popping when accelerating so its not driveable under boost at all. Is something wrong with ignition system? Spark not strong enough? :unsure:
I have been told that sparkplugs and wires are very critical parts in this model, so I already ordered them.
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It’s sounds by your description that it is running lean and not rich. I would get a fuel pressure gauge installed on it before I went any further. Once you know if the pressure is correct you can move on in the diagnosis.
Is there lots of fresh fuel in the tank, no water ?
I have tested fuel pressure and I think it was in specs. I maybe have to check it again. There is fresh fuel in tank. When I get it running it blows black smoke and smells very bad.
Well.. I noticed that when car was running there was steam coming from right side of the engine. Also when i topped up the coolant and replaced leaking cap the car was running rough for a minute and then it was impossible to start it again.. So there was pressure building in the coolant system cause the new cap and then forced the coolant in to cylinder? So faulty head gasket? Im just guessing but its not possible to do compression test because theres just not enough space.
Would testing for a vacuum leak around the cylinder head be of any benefit? Carb cleaner (very carefully), water or a propane wand? Seems that would check the head gasket for a failure anywhere. Black smoke is oil though isnt it? Would blow by be a culprit or that may be jumping to worst case scenario. Id check fuel pressure again, then a compression test to check the cylinders….or just jump to a leakdown test and listen through the tailpipe, oil fill, throttle body and look for bubbles in the radiator.
Thanks for the reply.
I really have to try that leakdown test. I never thought that test but It will definately tell me what is going on. I will try that next. I dont know when I have time to do the test, but when I get it done i will tell you. 🙂 I know its not impossible but it is really pain in the butt because theres all kinds of stuff in the way.I thought black smoke is rich condition– blue smoke is oil.
From:
http://www.freeasestudyguides.com/exhaust-color.htmlBlue/Gray Smoke: Blue/gray exhaust smoke is an indication of oil burning in the combustion chamber. These are possible symptoms and causes:
Valve Seals: Leaking valve seals will cause blue/gray smoke at startup because oil leaks past the seals into the cylinder after the engine shuts down.
Valve Guides: Excessive clearance between the valve stem and the valve guide allows oil to leak past the gap into the cylinder.
Piston Rings: Worn or damaged piston rings will cause blow-by resulting in blue/gray smoke.
Worn Cylinder Walls: Worn cylinder walls cause blow-by resulting in blue/gray smoke.
PCV System: A stuck closed PCV valve will cause excessive crankcase pressure resulting in blue/gray smoke.
Black Smoke: Black exhaust smoke is an indication of a rich fuel condition. These are possible causes:
Fuel Injectors: A leaking or dripping fuel injector will cause a rich fuel condition.
Fuel Pressure Regulator: A stuck closed fuel pressure regulator will cause a rich fuel condition.
Fuel Return: A restricted fuel return line will cause a rich fuel condition.
White/Gray Smoke: White exhaust smoke is an indication that coolant is burning in the combustion chamber. These are possible causes:
Cylinder Head: A crack in the cylinder head (around the coolant jacket) will cause coolant to enter the combustion chamber.
Engine Block: A crack in the deck of an engine block near the coolant jacket will cause coolant to enter the combustion chamber.
Head Gasket: A damaged or blown head gasket will cause coolant to enter the combustion chamber resulting in white/gray smoke coming from the tailpipe.
[quote=”Vkek” post=80202]Well.. I noticed that when car was running there was steam coming from right side of the engine. Also when i topped up the coolant and replaced leaking cap the car was running rough for a minute and then it was impossible to start it again.. So there was pressure building in the coolant system cause the new cap and then forced the coolant in to cylinder? So faulty head gasket? Im just guessing but its not possible to do compression test because theres just not enough space.[/quote]
If you start the engine cold and than shut it off a few minutes later and loosen the cap (be careful) is there pressure?
If there is, there is a good chance the head gasket might be damaged.
Raistian77,
Can you explain that? Wouldn’t a normal working car have some pressure if you remove the radiator cap after a few minutes of running?
Also, how would a bad head gasket cause a no start?
[quote=”juels98″ post=80494]Raistian77,
Can you explain that? Wouldn’t a normal working car have some pressure if you remove the radiator cap after a few minutes of running?
Also, how would a bad head gasket cause a no start?[/quote]
No. The reason is the pressure is generated by the heat. Heat=pressure and it takes a cooling system awhile to build up it’s maximum pressure. If you have high cooling system pressure after just a few minutes (less than 5) than there is combustion gasses going into the cooling system and pressurizing it. Coolant leaking into the cylinders (and vice versa) can interrupt the combustion process and result in a no start or very hard start.
We had a Neon in the shop that had a blown head gasket, you had to hold the throttle open to get it to run and after only 1 min of running the cooling system was under pressure.
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