OK - 267,000 miles

Having hesitation on normal acceleration and at times when cruising 60 - 75mph.

On heavy acceration - smooth going - no problem. MAF sensor was replaced 6 month ago when this issue first appeeared - seemed to take care of it - but it's back. No warning lights on dash... so no codes.

Shop tells me that there is a small coolant leak on intake manifold - but since so many miles - best not to mess with it - I keep an eye on coolant and top as needed.

Shop says they think hesitation is from deposits in upper head (?).

I'm no expert but couldn't this possibly come from the MAF sensor not good again or coil pack or blockage in muffler/cat system or vacuum leak somewhere? But, as I say, I'm just shooting in the dark...

I would appreciate any info or ideas - -

Thanks

Might be the sensor, but more likely to be a bad wire or plug or a weak coil. If the exhaust were restricted you would lose top end or if it's enough it won't even idle. I could also be a dirty or weak injector. Use an ohm meter to verify both ignition coil and injectors are good. If you've never done before, running a fuel cleaner (I like seafoam) may help clear up any blockages or restrictions in the injectors.

I would fix the coolant leak, you're wasting money in coolant by letting it leak out - which is a bad thing.

_________________
Boost addict


The Fleet:
'93 SSEi - Twincharged + manual Build thread
'97 Camaro - Top swap
'05 STS - V8, AWD, her DD
'92 Trofeo - Fair weather DD
'99 Montana - top swap 3800
'04 Sierra 2500HD - LLY Duramax

Current project:
Something cool, trust me.

Upcoming projects:
'92 Bonneville SSE
'87 LeSabre T-type
'67 LeSabre

Gone to greener pastures:
'84 Sierra Classic - Twin turbo 3800
'97 LeSabre - Top swap

RIP:
'86 LeSabre - pictures
'93 SE - L67

Thanks for the info Matt - I've had Seafoam coursing through it's veins for a couple of days - seems to be slightly better... but not gone - maybe it could use a week of Seafoam

Forgot to mention that if I'm accelerating hard - the shift from 3rd to overdrive at 60 - 65 bogs...

I'll have the garage check the coil, plugs, wires and injectors. Thanks again - much appreciated - and if anyone else has any thoughts - please feel free...

TP

Well - Turned out to be spark plug wires - got them replaced and now - smoooooooth cruising in the '90 SSE!

Thanks for the info provided -

Tom