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Discussion Starter #1
Hey guys, my 88 is running like crap. If I give it part throttle with no load, it will rev up slowly, but super roughly and it will blow a lot of smoke that smells like gas. Let off the gas, and it wants to die if I don't give it a little bit to keep it going. If I give it full throttle with no load, it seems like the injectors just shut off or something. No matter what rpm I'm at, go full throttle and combustion stops completely, rpm's drop like I shut the key off. Let off the gas, and combustion resumes like nothing happened. I'm assuming there's no fuel going in under full throttle, because it doesn't smoke.


Under load I still have to be careful how much and how quickly I give it gas, but once it gets going and into boost I can almost floor it without it dying. It runs strong once in boost, but if I go all the way open it will still die.

Everything I know about cars is telling me that it's somehow misfiring or running super rich, but I can't find the cause. And I have no clue why it's dying at WOT. TPS, IAC, cap, rotor, and plugs have all been replaced.

It's a 1988 with twin Garrett turbos, Edelbrock heads ported and polished, Edelbrock upper/lower intake, Accufab throttle body, CnL maf housing with a ford meter. Full MSD ignition, NGK plugs gapped at .040 or so, 255 lph pump, Kirban fuel pressure reg set between 35-40 psi dependng on intake pressure, and 42 lb injectors. Full exhaust. Any help would be appreciated. Thanks.
 

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Discussion Starter #4
I don't have a numeric guage, but AFR is in the stoichiometric zone 90 percent of the time, slightly to the rich side. When I let off the throttle it goes lean untill it's down to idle, then right back in the middle. It's been running weird all this year, I did a tune up and it improved a bit. It's strange though, three weeks ago it was running great, just had to warm up first. Now it's back to doing this again.
 

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I don't have a numeric guage, but AFR is in the stoichiometric zone 90 percent of the time, slightly to the rich side. When I let off the throttle it goes lean untill it's down to idle, then right back in the middle. It's been running weird all this year, I did a tune up and it improved a bit. It's strange though, three weeks ago it was running great, just had to warm up first. Now it's back to doing this again.
Are your readings from a wideband or narrowband sensor?

Under high vaccum deccel as seen when you let off the happy pedal, many systems have a fuel cut which would make your afr's read dead lean. If this is what's going on, it's normal.
 

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Hey guys, my 88 is running like crap. If I give it part throttle with no load, it will rev up slowly, but super roughly and it will blow a lot of smoke that smells like gas. Let off the gas, and it wants to die if I don't give it a little bit to keep it going. If I give it full throttle with no load, it seems like the injectors just shut off or something. No matter what rpm I'm at, go full throttle and combustion stops completely, rpm's drop like I shut the key off. Let off the gas, and combustion resumes like nothing happened. I'm assuming there's no fuel going in under full throttle, because it doesn't smoke.


Under load I still have to be careful how much and how quickly I give it gas, but once it gets going and into boost I can almost floor it without it dying. It runs strong once in boost, but if I go all the way open it will still die.

Everything I know about cars is telling me that it's somehow misfiring or running super rich, but I can't find the cause. And I have no clue why it's dying at WOT. TPS, IAC, cap, rotor, and plugs have all been replaced.

It's a 1988 with twin Garrett turbos, Edelbrock heads ported and polished, Edelbrock upper/lower intake, Accufab throttle body, CnL maf housing with a ford meter. Full MSD ignition, NGK plugs gapped at .040 or so, 255 lph pump, Kirban fuel pressure reg set between 35-40 psi dependng on intake pressure, and 42 lb injectors. Full exhaust. Any help would be appreciated. Thanks.
I had a similar problem not to long ago where at Idle I would give it gas and it acted like I was either not getting any spark or too much fuel. Also when I was cruising it whould buck like a wild bronco if I gave it a little gas. I finally figured that my tps and my 02's where bad. Now my car runs great.
 

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Check for vacuum leaks. Check all of your piping to make sure nothings loose or disconnected. Another thing to check is while the cars running take the radiator cap off and look for bubbles. Just finished tearing down my friends car with a similar problem to yours and his block was split right down the middle. It's not likely, but still possible. Those are just some standard problems related to your symptoms. Hey, maybe someone swapped your park plug wires.....
 

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Discussion Starter #10
Start by pulling the codes ................ let us know
I would, but I can't find the plug. There's a mess of aftermarket wiring under there, I searched for 20 minutes the other day and couldn't find it. I'm going to call the previous owner, hopefully he's got an idea of where it is.

Are your readings from a wideband or narrowband sensor?

Under high vaccum deccel as seen when you let off the happy pedal, many systems have a fuel cut which would make your afr's read dead lean. If this is what's going on, it's normal.
Thats fine, but it's when I go wide open throttle that the gas cuts out. And it's wideband.

I had a similar problem not to long ago where at Idle I would give it gas and it acted like I was either not getting any spark or too much fuel. Also when I was cruising it whould buck like a wild bronco if I gave it a little gas. I finally figured that my tps and my 02's where bad. Now my car runs great.
I already swapped the TPS, but I'm not even sure if the car has O2s. I'll have to take a look.

Check for vacuum leaks. Check all of your piping to make sure nothings loose or disconnected. Another thing to check is while the cars running take the radiator cap off and look for bubbles. Just finished tearing down my friends car with a similar problem to yours and his block was split right down the middle. It's not likely, but still possible. Those are just some standard problems related to your symptoms. Hey, maybe someone swapped your park plug wires.....
Checked everything already, that was the first thing I thought of. I guess I'll check firing order... I don't think that's it though.

seen is 88, did the map sensor still have the vacuum hose hook to the intake?
Should have stated, it's been converted to mass air.
 

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Thats fine, but it's when I go wide open throttle that the gas cuts out. And it's wideband. QUOTE]

What are the AFR's like as soon as you go WOT, after you go WOT and when it starts acting up?
 

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Discussion Starter #12
AFRs are always on the rich side of stoich, but I'll check them again and get back to you. It feels like it's rich but the guage doesn't say so.
 

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AFRs are always on the rich side of stoich, but I'll check them again and get back to you. It feels like it's rich but the guage doesn't say so.
IMHO, you need a gauge in there to tell you what your AFR's are. Simply being rich or lean does not tell you if you are safe....or let you know what's really going on.
 

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Discussion Starter #14
Well the car is definitely running rich, I let the car die and pulled the plugs, they were wet. Any ideas?
 

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Well the car is definitely running rich, I let the car die and pulled the plugs, they were wet. Any ideas?
You need a tune man. That wideband without an adequate gauge and a means to tune is not doing you any good.
 

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You need to start over.

If you do not know if you have 02 sensors and cant'd find the scan plug something is def. not right.

You could have a simple intermittent open in one injector circuit, or a whole host of problems.

IMHO you need to install everything yourself, and trust nobody's previous work. good luck.
 
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