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90' SE falls on it's face under load

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I bought a 1990 SE a few months back. The prevoius owner had it parked for most of the past 3 years, so I did a full service (timing and all other belts, fuel filter, plugs, air filter, rebuilt the chargecooler pump). I also repaired the exhaust manifold and then did the gaskets upon install. The car is running a de-catted exhaust, and Borla Muffler. It also has a specially developed turbo, and I switch between stock, S300, the #5, and #6 Red race chip.

My problem existed before all the above work was done and continues, to my great frustration...

It revs to the sky when parked. Revs pretty strongly when gradual throttle input is used, but god help me if I stab it, or mash the throttle when I'm in a higher gear and it puts the car under load. What happens then is a violent stutter, backfire, stumble, falling on it's face, as it refuses to allow full boost. I thought it was the chargecooler pump, but that did not fix the problem.

I had a freind sit in the car with a Lotus diagnostic tool hooked up (Tech 2). It showed no error codes when parked or moving untill I hit it. When the problems started to show, he "captured" the event on teh Tech 2. When he analyzed it, the reslults showed that the timing was being retarded by 20 degrees. Again, no error codes, no low load problems, but it's horrible to drive and NOT fast. Getting blown off by honda Civics is never fun, but especially in this car.

Please help! If it was an O2 sensor, knock sensor or something of that nature, wouldn't it have shown up as such in the form of an error code? I'm at my wit's end here. Any help is much appreciated.

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Does the boost gauge peg and then does it feel like you are running out of gas until the boost subsides then appears to run fine under non boost conditions?

Did you confirm both fuel pumps (primary/secondary) are working?

Use the stock chip or street chip to work on solving the problem first.

Did you check the wastegate, capsule, actuator hose to the capsule attached?

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Does the boost gauge peg and then does it feel like you are running out of gas until the boost subsides then appears to run fine under non boost conditions?

That is what it does allright. It actually runs OK under boost if applied smoothly up to .5 Bar as well. I still drive it and it runs perfectly right up untill I really stoke the fires.

Did you confirm both fuel pumps (primary/secondary) are working?

Did not confirm, but the Tech 2 indicates that it is dumping plenty of fuel into the engine

Use the stock chip or street chip to work on solving the problem first.

I did. It still does it, just not as badly. Still plenty annoying though...

Did you check the wastegate, capsule, actuator hose to the capsule attached?

I have not done that yet, and frankly am not sure what the capsule is or how to check it.

Thanks

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sounds like the std chargecooling /turbo probs with high boost.

is the chargecooler rad/pipes totally flushed through? and the best they can get?

how modded is the std turbo?

have u read this? :- http://www.wcengineering.com/esprit/turbo.html

Edited by pitstoppete

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I guess I'm relieved to hear that it's a standard problem, but what's the fix? The chargecooler pump was rebuilt very recently. I didn't do anything to the cooland pipes/hoses. Should I? I am just hoping it's something simple that I can replace like the knock sensor or 02 sensor, temp sensor someplace? I need to do something though. It's awful to have this car and not be able to drive it like it's intended to be. What's telling the brain to retard my diming by 20'???

I am running a special turbo. Stock housing with significantly not stock internals (impellers are both larger and changed angle), done by the shop that used to build the turbos for the World Challenge Esprits. The guy also does a lot of work for Garrett Air Research, so I'm sure that the turbo is good, and anyway, the same problem existed prior to the turbo swap out.

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i have a very similar problem on my 1997 gt3 at the moment.

more prodomenant in 4th or 5th. when getting to about 2000rpm with my foot the the floor i get the dam annoying shudder on the car, as if it is going to stall/backfire, and it just will not pick up. but if i gradualy feed the power it is fine.

sorry i cant really help much but ill be looking out for any other replies because its such an anoying fault

fingers crossed

dave

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I had a similar problem with my 89 SE (still do to a certain degree but I think thats due to a leak in the gasket between the manifold and turbo).

Had the car serviced by my local specialist who put the problem down to the throttle position sensor giving inaccurate readings and the crank sensor being coated in [email protected] so the poor ECU didn't stand a chance of knowing what the engine was doing.

They cleaned up the crank sensor, fitted a new throttle position sensor and did a temp fix on the manifold/turbo gasket and all was well after that.

Unfortunately, the gasket is now leaking again and with it has returned a fairly bad stumble between 2500-3000rpm (not the known common 3k stumble before anyone suggests that !!).

If you get your car hooked up to a laptop and Freescan, that will tell you if your sensor readings are all over the place and could well save you a lot of money in garage diagnostic charges / remedies.


Steve

89 SE Pacific Blue

http://lexi.mantaur.co.uk

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sounds good to me

will have freescan in a few days i hope :P

i have replaced the throttle possition sensor and did improve it. still there tho.

for anyone interested you can just repair your old throttle sensor.

take it off and soak it in some pure alcohol (isopropanol). if you dont have that you could use your missus nail varnis remover! but dont tell her!

then spray with wd40 and make sure you turn the sensor loads of times to get the carbon deposits off the carbon track.

then pop the lil beauty back on and bobs your uncle!

would recommend doing this anyway even if your not having problems.

it makes the drive so much smoother :(

where is the crank sensor situated buddy?

dave

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sounds good to me

will have freescan in a few days i hope  :P

i have replaced the throttle possition sensor and did improve it. still there tho.

for anyone interested you can just repair your old throttle sensor.

take it off and soak it in some pure alcohol (isopropanol). if you dont have that you could use your missus nail varnis remover! but dont tell her!

then spray with wd40 and make sure you turn the sensor loads of times to get the carbon deposits off the carbon track.

then pop the lil beauty back on and bobs your uncle!

would recommend doing this anyway even if your not having problems.

it makes the drive so much smoother  :(

where is the crank sensor situated buddy?

dave

<{POST_SNAPBACK}>

Dave's GT3 is another problem but yours is probablyrelated to the wastegate or actuator, maybe the capsule hose has been disconnected or leaking. The fuel cutoff on overboost is quite dramatic. If the overboost is detected the ECU will cut the fuel pump and ignition. The backfire occurs as unburnt fuel ignites in the exhaust. Once the wastegate can bleed off the overboost the fuel pressure and ingintion will be stable and you will have a smooth power transition.

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I really don't want to sound like a cretin here, but...

Have you changed your HT leads?

My SE stumbled like hell at boost, and i assumed wastegate/turbo area.

Turned out the (overstretched) longest HT lead had split inside the rubber

boot and was arcing itself to death. (route them carefully guys!)

:P

This was not evident by checking the plugs or the lead ends, and i only found

it when cutting the lead open (out of interest) looking for a problem because

fixing the new leads cured the problem!

OK, you probably have new leads, but i hadda say this as a cheap fix on an

Esprit is always worth a shot.

:(

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HT lead??? Spark plug wire or something else...

Not sure of the abreviation. Thanks for the thought though. If you are speaking of the spark plug wires, they look newish (red in color) but I have not changed them, and they are at least 4 years old.

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HT lead??? Spark plug wire or something else...

Not sure of the abreviation. Thanks for the thought though. If you are speaking of the spark plug wires, they look newish (red in color) but I have not changed them, and they are at least 4 years old.

<{POST_SNAPBACK}>

Yeah, the four sparkplug leads :ph34r:

Cheap part, and if they are not new then no harm in replacing them even if it

is not the cause of the problem (because they can give same symtoms).

:)

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