The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 1990 Chevy Suburban idle/accleration problems

cableguy0 · 08-17-2010, 05:47 PM

You need to check for vacuum leaks first and foremost. Where is your timing set at? Was it set with the est wire disconnected? If you hear an obvious whistle there has to be a vacuum leak somewhere. Lean codes also indicate a vacuum leak. It could be a lack of fuel but it wouldnt run better cold if it was fuel flow. Im gonna bet you have a massive vacuum leak somewhere and while the engine is in closed loop for cold start up the extra fuel being dumped for warm up is overcoming the vacuum leak.

08-17-2010, 05:47 PM	#2
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,950	Re: 1990 Chevy Suburban idle/accleration problems You need to check for vacuum leaks first and foremost. Where is your timing set at? Was it set with the est wire disconnected? If you hear an obvious whistle there has to be a vacuum leak somewhere. Lean codes also indicate a vacuum leak. It could be a lack of fuel but it wouldnt run better cold if it was fuel flow. Im gonna bet you have a massive vacuum leak somewhere and while the engine is in closed loop for cold start up the extra fuel being dumped for warm up is overcoming the vacuum leak. __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.