Boost Problem...will anyone ever have the answer?

[TurboCoupeWHITT]

ok my parents had a 87 turbo coupe with a five speed and the turbo blew out in it and they werent doing nothing with it ..... it had been sittin for about 4 to 5 years....and i decided i was goin to buy the factory turbo and swap it in ...so i bought the car off of my parents swapped it and .... changed all the vacum lines, belts, oil, oil and fuel filters, plugs everything........
got a boost controller off of a friend.. i know it works cause he was boost 25 psi in his talon and he got an elctronic boost controller and gave me his old one ...... when i boost 10 psi my car runs fine no problems in any gear.......then when i turn the boost to 15 the car bucks and **** like its being cut from fuel or the timing is being retarded.... so i checked my injectors replaced my o rings to my injectors and fule filter...... and it still cuts out and jumps when i try to boost above 10 psi.....anyone got any ideas????

 

[351wcoupe]

If you suspect its pulling timing.
1. check the timing w/ and without the SPOUT connected.
2. disconnect the knock sensor


My opinion......
If it doesn't do it at 10 but does over that check to make sure your hose clamps for the intercooler aren't leaking.

 

[NY Eric]

What did you tune up with. Unless you used Motorcraft parts you are asking fro probs in the turbo cars. Also check your timing with the spout out you should be 10DBTDC.

 

[NY Eric]

If you suspect its pulling timing.
2. disconnect the knock sensor
QUOTE]

Careful on this one yes it is a good Idea to check but Headgaskets go quick if you dont know what you are doing. Just My 2 cents.

 

[351wcoupe]

yeah thats definately a good point
thats why I mentioned checking the timing both ways first. Most people ignore the truth (including my post) but my teachers repeatedly tell me to address the cause of the problem not the effect.

 

[NY Eric]

chiming in

yeah thats definately a good point
thats why I mentioned checking the timing both ways first. Most people ignore the truth (including my post) but my teachers repeatedly tell me to address the cause of the problem not the effect.

Glad you didnt think I am steping on your toes. At forced4 we have had a run on headgaskets lately. It seems it is now fun to unhook the knock sensor and run the car till she blows.

I just thought I would mention the consequences of an accidental detonation.

 

[TurboCoupeWHITT]

ok i toolk my car to my freinds house who is a mech... and had a timing gun and knows what he is doin ....he said my car was in time and he said he thinks the knock sensor is ****ed up and told me if i unplugged it i should be fine......then it started raining and i was goin to run more boost but the rain messed that up cause everyone know TC are bad on wet streets...so until then is there anything i should check

 

[Stinger]

The knock sensor won't cause that...

Sounds like a boost leak between turbo and throttle body, your vam hose is sucking shut, or your fuel pressure regulator is bad...

 

[351wcoupe]

My opinion......
If it doesn't do it at 10 but does over that check to make sure your hose clamps for the intercooler aren't leaking.

I agree...

 

[TurboCoupeWHITT]

Hmmm i had my hopes up tha it was that.........but now i guess its back to checking my intercooler hoses, buy a new fuel press. reg. , and about the vam hose how would u check that ...

 

[Stinger]

Don't buy a fuel pressure regulator...just check your fuel pressure...it's WAY cheaper

Make sure the vam hose has a coiled wire inside of it that holds the hose open...

You can also grab the hose and see if there is tension when you try to squeeze it shut or if it's really flimzy.

 

[mightypoof]

If your going to buy a FPR then get an adjustable one for a few bucks more, you'll be happy in the long run...Especially If your turning the boost up.

 

[TurboCoupeWHITT]

ok my vam hose is holding up strong ive checked my intercooler connections ......so i guesss next is to check my fuel pressure ... more than likley purchase pressure reg... anyone have any suggestions on what brand to buy that reliable ... and what psi should my fuel be pushing

 

[Stinger]

Get a Kirban unit for an 87-95 5.0 Mustang...should only be about 65 bux if you shop for them.

It should be ~38psi at idle with the vacuum line removed from the top of the regulator.

 

[a351Must2]

Did you ever answer if you used Motorcraft parts for your tuneup? It's unbelievable how picky these engines are about the spark plugs, wires, and coil used. The only spark plugs I'd trust are Motorcraft or NGK...anything else and you're likely not even sparking above 10psi of boost.

Ask your buddy with the DSM what happens if he uses anything other than NGK... I used Bosch in my DSM once and took it to the dealer because I couldn't get more than 3psi before the engine started bucking/missing.

 

[TurboCoupeWHITT]

Yeah Motorcraft all the way..... ill ask my friend with the DSM.....or ill tell him more liek it cause we are tearing his motor apart puttin new pistons in it and he is boring it 20 over and putting pretty much everything in it new and swaping a 16G for his turbo and a Front mount intercooler ill be sure to tell him to get NGK plugs...thanks for the advice.. im getting ready to get a 91 Talon my self cause ive road in my other friends Evo 8 and the awd has got my by the heart .... i love the power and traction awd gives u...

 

[TurboCoupeWHITT]

ok the problem was a simple plug after all i went and changed the crappy plugs and put some NGK in it and it boosts whatever iw ant it 2... im runnin 18 psi right now i love it all though im goin to crank it down to around 17 psi thanks for the help every one