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Hey guys,
I am having a hesitation issue with my '91 GTP 5 speed. I bought the car in July of 2010 with 197k on it. It now has 208k. Since I have owned this car, it has had a tip in hesitation which is temperature related. For example on a cold winter day ~20 degrees fahrenheit on a cold start, the first 2 or so minutes are very smooth and hesitation free. After about 2 minutes, the hesitation crops up and gets worse as the engine temp increases. The hesitation is at its worst at about 130 degrees. Once the engine warms up to 195, the hesitation is still noticeable, but much less so. If the outside air temp is like 40 degrees or higher, the hesitation is there right from the start, even on a cold start. I guess I should describe the hesitation. Every time you crack the throttle, the engine cuts out to an extent momentarily, causing the engine to rock back and then forward again about once; sometimes a bit violently and then it gets over it. If you roll onto the throttle extremely (and I mean extremely) gently you can just about avoid it. The engine performs fine; it's got good power and runs smoothly except for said hesitation. I have checked the fuel pressure (45psi; service manual says 40-47 is acceptable), MAP sensor values look fine. Even switched MAP sensors with another car and it made no difference. No SES light. I drove the car twice right after I bought it in July before pulling the engine to do some repair, and it had the hesitation then. While the engine was out, I replaced the timing belt and chain, bottom end, and some other things including the TPS. When I had the car running again a few months later, the hesitation still existed and had not changed a bit. I bought a 3.4 service tool kit for the thing, figuring the cam timing was off a touch. I pulled the cam gears off, bolted my homemade hold downs on the cams (service tool kit was missing the cam hold downs), etc. and put it back together. Hesitation was unchanged and still exists. Have you guys experienced anything like this before? I really like this car, but this hesitation's about to drive me wild! What should be my next move?
Thanks,
Andy
I am having a hesitation issue with my '91 GTP 5 speed. I bought the car in July of 2010 with 197k on it. It now has 208k. Since I have owned this car, it has had a tip in hesitation which is temperature related. For example on a cold winter day ~20 degrees fahrenheit on a cold start, the first 2 or so minutes are very smooth and hesitation free. After about 2 minutes, the hesitation crops up and gets worse as the engine temp increases. The hesitation is at its worst at about 130 degrees. Once the engine warms up to 195, the hesitation is still noticeable, but much less so. If the outside air temp is like 40 degrees or higher, the hesitation is there right from the start, even on a cold start. I guess I should describe the hesitation. Every time you crack the throttle, the engine cuts out to an extent momentarily, causing the engine to rock back and then forward again about once; sometimes a bit violently and then it gets over it. If you roll onto the throttle extremely (and I mean extremely) gently you can just about avoid it. The engine performs fine; it's got good power and runs smoothly except for said hesitation. I have checked the fuel pressure (45psi; service manual says 40-47 is acceptable), MAP sensor values look fine. Even switched MAP sensors with another car and it made no difference. No SES light. I drove the car twice right after I bought it in July before pulling the engine to do some repair, and it had the hesitation then. While the engine was out, I replaced the timing belt and chain, bottom end, and some other things including the TPS. When I had the car running again a few months later, the hesitation still existed and had not changed a bit. I bought a 3.4 service tool kit for the thing, figuring the cam timing was off a touch. I pulled the cam gears off, bolted my homemade hold downs on the cams (service tool kit was missing the cam hold downs), etc. and put it back together. Hesitation was unchanged and still exists. Have you guys experienced anything like this before? I really like this car, but this hesitation's about to drive me wild! What should be my next move?
Thanks,
Andy
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