surging problem 951 ????

[ketchum951]

Hi everybody , again the never ending problem in 951 !! a short description of my problem, my car is 951 86 it has 27 , tial wg, 3barfpr, manual bc, deleted cycle valce, he start giving me surges and trying dieing, and also couple times , after running and turn off for gas or just in restuarant after 25 minut didn;t want start it start after pulling it or juper with electrical cables, any way preplace new alternator, new starter, new tps, new ecu temp sensor, new blowoffvalve, new gas damper, new filter full new tune up cap rototr, magnecor wires, car still surges, even new ecu fuel pump relay, and same thing surges and not strating, took car to 2 different porsche shops, almost 6 in one shop and 2 in last one , first mechanic thoughts were car was over boosting , and he basic didn't do nothing he found smal leak exhaust by wastedgate he took car of it, new blowvalve, and damper--------------------- new mechnanic said is electrical problem, he looks for vacuum leaks, check fine, he replace speedreference sensors, and clean grounds he found one ground not good, by engine wall, anyhow, he check all rest of stuff like air fuel meter and cap rotor, wires, coil all chack fine I live 3 hrs away from porsche shop, so ll this convesations with shop are by phone mechanic report car improve and drive better after fixing ground but still surging a little, so i went and bought ecu and klr from know good working car and stock set chips 450.00 anyway mechanic replace that yesterday and test drove car he said car is much much better and he needs to adjust micture, So today i was praying for a good final answer (car is fixed!!) mechanic said try new ecus, with performance chips, said car run much much better that stock chips, but car is still surging a little, he said he will correct mixture, and give him call tomorrow I"m getting sick of all deal, searching looking in web, thing for hrs waht can be wrong !!!! I alredy replace alot of stuff with new parts spend $$$ plus this mechanice will kill me at 75$ hrs--------what else can be wrong
the main question what things produce surges in 951??? having in mind out of parts we alredy replace and he check!! i was thinking a bad fuel pump, can do this ? bad injectors, maybe engine harwaht were are missing ? is there anyother sensor, and trick you guys know that I can make mechanic go and check!!!
A bad fuel pump can give that surges?
a bad injector?
bad engine harness??
whats is deal????

[robs944]

just a guess but clogged/bad injector?
had an "surging" issue with my 951 (only stage II chips) removed injectors and had them
cleaned. Fixed my problem.

Here is the thread I had Fuel problem or something else?

Soxnail gave me a good explanation on why it could be injectors.
Hopefully it's something simple, after all the time and $$ you have into it.

[myskyon]

my surging problem i had on my first 951 was due to the cap not being put on correctly. so it would boost wierd and mis then be fine. then go bad. the cap did look like it was on correctly but it wasnt. it even felt tight.

[clarkeph]

+1 for injectors. Sounds like the only thing left, I agree take them out and have them checked and/or replaced.

clarkeph

87 951 all rebuilt, LR turbo, dpw, mbc, chipped 18" 993 wheels, no leaks!