[kneesrbad2]

Have an 89 deville 4.5 which I have been trying to solve the hesitation problem. Replaced EGR, cleaned EGR tubes and throttle body completely did not fix my problem. Now I get the following Codes E71, E72, E74, E76, E77, E78! Can someone please tell me if this indicates a bad MAP Sensor or is there something else I am missing? Car hesitates when I take my foot off the accelerator or try to give it gas. Idles terrible now!

 

[adalla]

Bunch of codes usually a good indication of poor electrical contacts. Inspect battery cables, connections, grounds. Another thing to look at is ECM (the computer). In my car it is under the glove box. Remove the glove box and tap the computer. Watch if tapping affects the idle.

 

[opelgt19]

those are not error codes,
they are the ecm switch test codes
error codes show up before 7.0 is shown.
7.0 is the decision-point for various tests you can perform.
that being said...............its quite possible to have no codes and still have your problem.
you need to check or "recalibrate" your TPS sensor
and also engine timing. follow the manual and don't try to shortcut steps.
if either is incorrect then the car will run correctly but still have a hesitation on takeoff. if they are correct post back and we'll try some other things.

 

[kneesrbad2]

Thank you for your response and yes those codes did come after the 7.0 code not before. I do not have a manual so I don't know what you are talking about re the recalipration of the tps and timing! Should I take it to the blood sucker or is there somewhere here I can find out what to do on my own?

 

[opelgt19]

if you have acess to a timing light, and can use basic functions on a multimeter you can do it all yourself.
a factory service manual is preferred because of the detailed information.
a Chilton's manual is "adequate" at best for basic things but does cover timing and TPS.
you can find factory service manuals on ebay for $40-$50 usually.
several of the auto parts stores carry Chilton's Manuals-they are about half-price of a Factory SM because they only have about half the information.
beware though Chilton's makes TWO manuals, a cheapie $9.99 version and a $19.99 version. get the $19.99 version it will say
"wiring & vaccum diagrams "on the front cover & contains more information. worst case check your local library, they often have several available.

P.S. they also contain the codes and their meanings.

 

[adalla]

FSM on eBay may be as cheap as $10.